Wednesday, December 26, 2018

Relay Voltage Spike Glows 24 LEDs in Series




As the circuit schematic above. The relay (RL) is activated by a voltage of 4.5 volts. The relay switch is connected to one LED with a current limiting resistor (R). In the relay coil installed several LED in series.

Component details are as below:
RL 8 pin Double Pole Double Throw (DPDT) relay with 5 volts coil voltage.
5 mm diameter LED, blue colored
R 10 kilo ohms resistor value
30 LEDs are 30 pieces of 5 mm diameter LED connected in series

30 LEDs connected together but in the schematic are only three of them shown, to make the schematic looks simpler. The colors chosen are red, white, and green, to make them look different. This 30 series LED are connected in reverse direction to the supply current,

Seen in the video below, when activated the relay will supply current to a blue LED. The video shows that the blue LED will be lights up immediately after the relay is connected to the adapter. The relay coil becomes active, and it becomes an electromagnet.



When the adapter is disconnected, the blue LED immediately turns off and the relay is off. Then after the blue LED is off, some series LEDs will light even though the supply current from the adapter has been disconnected. Because those series LEDs get power from the relay coil, not from the adapter. This current comes from the induction of the magnetic field that collapses in the relay coil, also called spike voltage. The current direction from the coil is in the reverse direction of the adapter current. Therefore the serie LED is installed in reverse of the adapter current direction.

On the relay coil pin which is connected to the positive wire from the adapter, a crocodile clip is installed to choose the number of series LEDs to be connected on matrix circuit board.


As the above photo, maximum 24 LEDs series can be glowed by spike voltage. If one LED has a voltage of about 3 volts, the estimated voltage for 24 LEDs is around:

 3 x 24 = 72 volts.

The actual spike voltage is actually higher, around 200-300 volts. Although the current is very small and the period is less than 1 second, spike voltage can damage transistor and IC (Integrated Circuit). Installation of reverse diode as a snubber can reduce spike voltage.

If all series LEDs are connected to a total of 30 LEDs, there will be a shortage of voltage in some LEDs. So those LEDs with low voltage cannot light up.

LEDs require a minimum current to light up. If the current is smaller than the minimum current, even though the voltage is very high, the LED will not turn on.

Sunday, December 23, 2018

Lonjakan Tegangan Relai Nyalakan 24 LED Serie



Sebagaimana skema sirkuit di atas. Tampak sebuah relai (RL) disuplai dengan tegangan 4,5 volt. Saklar relai tersambung dengan satu buah LED dengan resistor pembatas arus (R). Pada koil relai terpasang beberapa buah LED serie.

Detail komponen adalah:
RL relai 8 pin Double Pole Double Throw (DPDT) dengan tegangan koil 5 volt.
LED diameter 5 mm, berwarna biru
R nilai resistor 10 kilo ohm
30 LEDs adalah 30 buah LED diameter 5 mm yang tersambung serie

30 LED yang tersambung serie tapi pada gambar pada skema cuma tiga buah, agar skema tampak lebih sederhana. Warna yang dipilih adalah merah, putih, dan hijau, agar tampak berbeda. 30 LED serie ini terpasang terbalik arah terhadap arus suplai,

Terlihat dalam video di bawah, jika diaktifkan, relai akan memasok arus ke satu buah LED biru. Pada video terlihat bahwa LED biru pada relai akan menyala segera setelah relai diberi arus dari adapter. Dan koil relai jadi aktif, menjadi elektromagnet.

Saat arus dari adapter terputus, LED biru segera mati dan relai non aktif. Kemudian setelah LED biru mati, beberapa buah LED serie akan menyala walau suplai arus dari adapter sudah terputus. Karena lampu-lampu LED serie tersebut mendapat daya lisitrik dari koil relai, bukan dari adapter. Arus ini berasal dari induksi medan magnet yang runtuh dari koil relai, disebut juga voltage spike. Mungkin bisa diartikan sebagai lonjakan tegangan. Arah arus dari koil kebalikan arah arus dari adapter. Oleh karena itu LED serie dipasang terbalik dari arah arus dari adapter.


Pada kaki koil relai yang tersambung pada kabel positif dari adapter, dipasang capit buaya agar bisa memilih jumlah LED serie yang akan tersambung pada papan sirkuit matrix (matrix circuit board).


Sebagaimana gambar di atas, maximal 24 LED serie dinyalakan oleh tegangan spike. Jika satu LED bertegangan 3 volt, maka estimasi  tegangan untuk 24 LED adalah sekitar :

 3 x 24 = 72 volt. 

Tegangan spike aktual sebenarnya lebih tinggi, sekitar 200-300 volt. Walaupun arusnya sangat kecil dan periodenya kurang dari 1 detik, tegangan spike dapat merusak transistor dan IC (Integrated Circuit). Pemasangan dioda terbalik sebagai snubber (peredam) dapat mengurangi tegangan spike.

Jika semua LED serie disambung menjadi total 30 buah LED, akan terjadi kekurangan tegangan pada beberapa LED (voltage drop). Sehingga LED yang kekurangan tegangan tersebut tidak bisa menyala.

LED membutuhkan arus minimal agar menyala. Jika arusnya lebih kecil dari arus minimal, walau tegangannya sangat tinggi, maka LED tidak akan menyala.



Wednesday, December 19, 2018

Recharge 9 Volts Battery Alkaline Non-rechargeable

Non-rechargeable 9 volts alkaline batteries usually cannot be recharged. But actually it can be recharged, though not as good as new or not as good as a rechargeable battery. This procedure is very helpful if you have no time to replace the battery with a new one. Good quality 9 volt batteries can usually be recharged many times.

The following video shows the process of charging a non-rechargeable alkaline 9 volts battery.


Before being charged, make sure the battery voltage is not less than 7.2 volts. The battery condition is still good, does not leak, does not rust. Charging is carried out with a voltage of 12 volts. In video, the charging power comes from the 12v adapter.


In the photo above, the battery voltage is still about 7.9 volts, and the battery condition is still good.

Connect the positive wire of adapter to the positive pole of battery, and the negative wire of adapter to the negative pole of battery. Let it connects for around 30 seconds. It needs only a small charging current about 10 mA for this 9v battery.


As the photo above, the black clip is negative and it is connected to the battery negative pole. The red clip is positive and it is connected to positive pole of battery.

Do not recharge too long, because the battery can get hot. Let it cools for a few moments. If the voltage is still low, then recharge it again.

After recharging the battery voltage reaches 9 volts. One LED voltage is of around 3 volts. Because there are 3 lights arranged in series, then the LED voltage is 9 volts. The light becomes brighter, after the battery is recharged.

Tuesday, December 18, 2018

Cas Baterai 9 Volt Alkaline Non-rechargeable

Baterai 9 volt alkaline non-rechargeable biasanya tidak bisa dicas. Tapi sebenarnya bisa, walau tidak sebaik baterai baru maupun sebaik baterai rechargeable. Prosedur ini sangat membantu jika belum sempat mengganti baterai dengan yang baru. Baterai yang berkualitas bagus biasanya dapat dicas berkali-kali.

Video berikut memperlihatkan proses pengisian baterai 9 volt alkaline non-rechargeable.


Sebelum dicas, pastikan tegangan baterai tidak kurang dari 7,2 volt. Kondisi baterai masih baik, tidak bocor, tidak berkarat. Pengisian dilakukan dengan tegangan 12 volt. Dalam video, tegangan pengisian berasal dari 12v adapter.


Tampak pada foto di atas tegangan baterai masih sekitar 7,9 volt, dan kondisi baterai masih baik.

Sambungkan positif kabel adaptor ke positif baterai, dan negatif adaptor ke negatif baterai. Biarkan tersambung selama sekitar 30 detik. Kebutuhan arus pengisian kecil saja sekitar 10 mA untuk baterai 9 volt ini.


Sebagaimana foto di atas, jepit berwarna hitam adalah negatif dan dihubungkan ke negatif baterai. Jepit berwarna merah adalah positif dan dihubungkan ke positif baterai.

Jangan terlalu lama mengisi, karena baterai bisa panas. Diamkan beberapa saat agar mendingin. Jika tegangan masih kurang, lalukan pengisian kembali.

Sesudah dicas tegangan baterai mencapai 9 volt. Sebuah lampu LED bertegangan sekitar 3 volt. Karena ada 3 lampu tersusun serie, maka LED voltage adalah 9 volt, nampak cahayanya lebih terang setelah baterai dicas.

Sunday, December 16, 2018

Printed Circuit Board (PCB) Without Etching

This procedure for making copper trace of Printed Circuit Board uses only cutter and soldering iron.. Cheap, easy and fast, this procedure is suitable for simple electronic circuit. The sample PCB prototype in this article will be used for brake lights flashing circuit with adjustable frequency.


Draw the copper conductor paths on the PCB. In this procedure, the conductor that covered in ink will be removed. The finished PCB copper traces are wide and can transmit big current, it cools the circuit, and conductor is not easily damaged if soldered too often or too hot. Therefore this PCB is suitable for simple circuits with high power and current.

Whereas in the chemical dyeing procedure (etching), the copper part covered in ink will be used as a conductor. And the part that is not covered with ink will disappear because it dissolves in a chemical solution.

This procedure can also be seen on the following YouTube videos:


The first video above shows the process: drawing, punching, drilling, and scratching or cutting the conductor. Note that only copper conductors are cut. The non conductor layer (substrate) of PCB is not cut.



The second video shows the process: widen the gap between conductors, test adjacent conductors, cut the PCB.



Mark points that will be drilled with punch, you can also use nail. Those punch marks will ensure drill bit does not slip, when it first hits the PCB.


Drill all component holes with diameter drill as needed, usually 1 mm diameter drill bit.



Cut copper according to the line drawn. Note that only the copper conductor is cut. While the non conductor layer (substrate) is not cut. For this reason, the cutter knife should not be pressed too hard, and must be scratched several times. It will feel lighter when scratching if the copper has been cut. The shape of  conductor will be quadrilateral-like, because this shape is easily made with a knife scratch.



Then the gap is formed between copper, it is widened by heating with soldering iron. Make sure the solder tip is pointed and clean of lead and dirt, to make it easier and the results are neat. The video shows that copper debris is released when heated and pushed by soldering iron, and the gap widens.



Check conductivity with ohm meter. If between two adjacent conductors is still connected (short circuit), then scratch the knife again, and expand the gap again with soldering iron.



If there is nothing conductor short circuit. Then the PCB can be cut. Cutting is the last thing to do, to make it easier to hold the PCB during the process. If the PCB is too small, it is difficult to hold it. If cutting using a cutter it must be scratched several times.



The cutter knife must also scratch the back of the PCB also, or the non conductor layer (substrate).

Cutting can also be done with a hacksaw or a plywood saw.

Thursday, December 6, 2018

Buat Jalur PCB Tanpa Kimia Etching

Prosedur pembuatan jalur konduktor Printed Circuit Board ini hanya menggunakan pisau cutter dan solder. Mudah, murah dan cepat, cocok untuk rangkaian elektronik sederhana. Papan PCB prototype ini akan digunakan untuk rangkaian lampu rem berkedip dengan frekuensi kedipan dapat disetel.



Gambarkan jalur konduktor tembaga pada PCB. Pada prosedur ini, bagian yang terkena tinta adalah garis atau bagian konduktor yang akan dihilangkan. Sehingga jalur PCB menjadi lebar dan dapat menghantar arus yang besar, dapat mendinginkan rangkaian, dan konduktor tidak mudah rusak jika disolder terlalu sering maupun terlalu panas. Cocok untuk rangkaian sederhana dengan daya dan arus besar.

Sedangkan pada prosedur celup kimia (etsa, etching), bagian tembaga yang tertutup tinta yang akan dipakai jadi konduktor. Dan bagian yang tidak tertutup tinta akan hilang karena larut dalam larutan kimia.

Prosedur ini juga dapat dilihat pada video YouTube berikut:


Video pertama di atas memperlihat proses: menggambar, menandai (punch), melubangi, dan menggores atau memotong konduktor. Perhatikan yang dipotong hanya konduktor tembaga saja. Bagian non konduktor (substrat) tidak sampai terpotong.



Video kedua memperlihat proses: melebarkan celah di antara konduktor, uji konduktor yang bersebelahan, memotong PCB.



Tandai titik yang akan dibor dengan alat pons (punch), bisa juga dengan paku. Tujuannya agar mata bor tidak meleset saat pertama kali mengenai PCB.



Bor semua lubang komponen dengan diameter bor sesuai kebutuhan, biasanya mata bor diameter 1 mm.



Potong tembaga sesuai garis yang digambar. Perhatikan, yang terpotong hanya lapisan konduktor tembaga saja. Sedangkan lapisan non konduktor (substrat) tidak terpotong. Untuk itu, pisau cutter jangan terlalu ditekan kuat, dan harus digoreskan beberapa kali. Akan terasa lebih ringan saat menggores jika tembaga sudah terpotong. Bentuk konduktor-konduktor yang mirip segiempat adalah karena bentuk inilah yang mudah dibuat dengan goresan pisau.



Selanjutnya celah yang terbentuk di antara tembaga, diperlebar dengan memanaskan dengan solder. Pastikan ujung solder runcing dan bersih dari timah dan kotoran, agar lebih mudah dan hasilnya rapi. Pada video tampak serpihan tembaga terlepas saat dipanaskan dan didorong solder, sehingga celah melebar.



Uji konduktivitas dengan ohm meter. Jika di antara dua konduktor bersebelahan masih menghantar (korslet, short circuit), maka goreskan pisau lagi, dan perlebar lagi celahnya dengan solder.



Jika tidak ada lagi konduktor yang korlset. Maka PCB bisa dipotong. Pemotongan terakhir dilakukan agar mudah memegang PCB saat proses berlangsung. Jika PCB terlalu kecil maka sulit untuk memegangnya. Jika memotong dengan menggunakan cutter maka harus digoreskan beberapa kali.



Pisau cutter juga harus menggores bagian belakang PCB, atau bagian non konduktor (substrat).

Pemotongan juga bisa dilakukan dengan gergaji besi atau gergaji tripleks.


Monday, December 3, 2018

Red Amaryllis Flower Hippeastrum Puniceum Blooming


This video consists of several photos when the red amaryllis is blooming. Then followed by a video recording from close up distance showing the inside of the crown (corrolla) with six petals. We can see clearly stigma and style as part of pistil. Also we can see anther and filament as parts of stamen.


According to the consensus of botanists in 1987, this type of flower plant was called hippeastrum, not amaryllis. With the species full name is hippeastrum puniceum. But the amaryllis name is already famous.



As can be read on Wikipedia. Hippeastrum's name is given by William Herbert which means "Knight's-star-lily". Over the years there has been confusion among botanists in the generic name of amaryllis and hippeastrum. One conclusion is that the common name "amaryllis" is actually genus hippeastrum, often sold as indoor flower bulbs especially on Christmas in the northern hemisphere and popular as Christmas amaryllis bulbs. As of November 2013 Hippeastrum was recorded to have 91 species. Usually the most expensive price is the double petal varieties, the flowers are double in one petal so that they resemble roses.

The genus name of amaryllis applies to flower plant from South Africa, usually growing outdoors. Amaryllis is relatively difficult to adapt, if compared to hippeastrum. So far only two species of amaryllis have been recorded: amaryllis belladonna and amaryllis paradisicola

Amaryllis is also known as: belladonna lily, jersey lily, naked lady, amarillo, easter lily in southern Australia, march lily in South Africa.

Both amaryllis and hippeastrum are in the same subfamily amaryllidoideae

In tropical environment such as in Jakarta, this hippeastrum plant is easy to maintain. Hippeastrum likes direct sunlight to make it diligent in flowering. Although it can live in the shade or indoor, but it will be difficult to flower. Photos of blooming flower are put together to become a video, taken from around 7:00 to 13:00. With an interval of taking photos every 10 minutes.

See also the bloom of four pink amaryllis flowers.




Wednesday, November 28, 2018

Mekarnya Bunga Amaryllis Merah Hippeastrum Puniceum



Video ini terdiri dari beberapa foto saat amaryllis merah sedang mekar. Selanjutnya diikuti dengan rekaman video dari jarak dekat memperlihatkan bagian dalam dari mahkota (corolla) terdiri dari 6 helai (petal). Terlihat jelas kepala sari (antera), tangkai benang sari (filament), kepala putik (stigma), dan tangkai putik (style).


Menurut konsensus para ahli botani di tahun 1987, jenis ini bernama hippeastrum, bukan amaryllis. Dengan nama lengkap spesies hippeastrum puniceum. Tapi nama amaryllis sudah terlanjur terkenal.


Sebagaimana dapat dibaca di Wikipedia. Nama hippeastrum diberikan oleh William Herbert yang bermakna "Knight's-star-lily", mungkin bisa diartikan sebagai lily bintang ksatria. Selama bertahun-tahun ada kebingungan di kalangan para ahli botani atas nama generik amaryllis dan hippeastrum. Salah satu kesimpulannya adalah bahwa nama umum "amarilis" sebenarnya adalah genus hippeastrum, sering dijual sebagai umbi bunga dalam ruangan terutama pada Natal di belahan bumi utara. Pada November 2013 hippeastrum tercatat mempunyai 91 spesies. Biasanya yang harganya paling mahal adalah varietas double petal, bunganya berganda dalam satu kelopak sehingga mirip mawar.

Nama genus amaryllis berlaku untuk tanaman bunga dari Afrika Selatan, biasanya tumbuh di luar ruangan. Amaryllis relatif sulit beradaptasi daripada hippeastrum. Sejauh ini hanya dua spesies amaryllis yang tercatat yaitu: amaryllis belladonna dan amaryllis paradisicola

Amaryllis juga dikenal dengan nama: belladonna lily, jersey lily, naked lady, amarillo, easter lily di Australia selatan, march lily di Afrika Selatan.

Amarilis dan hippeastrum berada dalam subfamili yang sama yaitu amaryllidoideae.

Pada lingkungan tropis seperti di Jakarta, tanaman hippeastrum ini termasuk mudah untuk dipelihara, dan menyukai sinar matahari langsung agar rajin berbunga. Walaupun bisa hidup di tempat teduh, tapi akan sulit berbunga. Foto-foto bunga sedang mekar yang kemudian disatukan menjadi video, diambil mulai dari sekitar jam 7 pagi sampai jam 13 siang. Dengan selang waktu pengambilan foto setiap 10 menit.

Lihat juga mekarnya empat bunga amaryllis warna merah jambu.


Sunday, November 25, 2018

Adjustable Frequency Brake Light Simple Flasher


This simple adjustable electronic flasher circuit uses a relay controlled by a transistor, so that its frequency can be adjusted easily with a trimpot (trimmer potentiometer). See the video when the circuit is tested for frequency adjustment.


Also watch the video when the circuit is connected to the third brake light on the car, or the center brake light.


The following is a list of components that are simple and inexpensive but effective as the above schematic.

R = 5 pins relay SPDT (Single Pole Double Throw) 12 volts
D = diode 1N4007
T = transistor BC109C
Rb = 10 kiloohms trimpot
Rc = 120 kiloohms resistor
C = condenser or capacitor 33 microfarads 25 volts
B = brake light

Relay (R) is SPDT five pins. SPDT stands for Single Pole Double Throw. Two pins of the relay are used to activate the solenoid, and the other three pins as switches. See the relay switch circuit, NC (Normally Closed) pin is connected when the relay is off, this pin is connected to the bulb and supply current to charge the condenser (C).

This flasher relay will turn on the brake light if the relay is not active. The relay will be active when the condenser voltage is above 0.6 volts. If the relay is active, the current to the lamp and condenser will be disconnected, because the relay connects to the Normally Open (NO) pin. The brake light will turn off. The condenser supplies current to the base of the transistor, the transistor connects the solenoid to negative. So the relay will be active for a while, and the brake light will still off. When the condenser voltage is lower than 0.6 volts, the transistor cuts the current and the solenoid relay will off. Then the NC pin will be reconnected, the light is on and the condenser is charging again. And the cycle will continue.


As shown in the circuit photo, the 12 volts relay is an orange colored Schrack type TN313012. This relay allows direct current at a maximum of 7 amperes. So for 12 volts, the maximum load power relay, in this case the brake lamp, is about = 12 x 7 = 84 watts.

Diode (D) will short high voltage (spike), which arises when the current to the solenoid is cut off. This spike can damage the transistor. The spike arises because collapsing solenoid magnetic field induces a high voltage in the opposite direction of supply current. That is why this diode is installed backward.

The BC109C is an NPN transistor switch (T). This transistor will allow the current from the solenoid relay flow to negative when the voltage at transistor's base is above 0.6 volts. This transistor has a metal body. So if it is overheated, a cooling fin can be installed. From the test results the temperature of the transistor does not rise even though the flasher is tested for several hours.

Trimpot (Rb) with a value of 10 kiloohms will determine the length of time to discharge condenser. So it determines the length of time of activating relay and the light is off. The frequency can be changed when this trimpot is adjusted. The greater the Rb value, the longer the condenser is discharging, the longer the light off, and the lower the frequency.

The 120 kiloohm resistor (Rc) determines the length of time the condenser is charging. In other words, the duration of the relay is inactive and the light is on. The greater the value, the longer the light on. This resistor also determines the amount of current supplied to the transistor base. So it determines the amount of current supplied to the relay solenoid. If the relay current is too small, the relay is difficult to activate. From the test results it is known that Rc resistant value 330 kiloohms will make the relay difficult to activate.

Actually the Rc can also be replaced with a trimpot, so that it can be adjusted. But too many adjustments can also be troublesome. The transistor also has a maximum base current limitation, so if the Rc is replaced by the trimpot, then the risk of the maximal base current is exceeded and the transistor will be damage.

The 33 microfarad condenser (C) determines the length of time of the light to turn on, and also determines the length of time of the light off. The greater the value, the lower the frequency.

The brake light (B) is connected to the Normally Close (NC) pin of relay. If the system does not work, the brake light will remain on but not blinking. So with this design, it is still safe for the car or motorcycle that using this circuit, although it is not function properly.

The video shows an LED light as an indicator. If you want to add a 5 mm LED light, it is simple by connecting LED to the relay pin using a resistor with a value of about 2.2 kiloohms. The LED will light up quite brightly. Installation of LED can also be read on simple relay flasher articles.

12 vdc input voltage is connected to a positive wire of the brake light wiring, or a positive wire from the brake pedal switch.

This circuit can also be applied as a turn signal flasher relay. An easy way to make a printed circuit board (PCB) for this circuit can be read in the article making PCB without chemical.

Flashing brake light is a very new technology. So the regulations are still ambiguous in several places. For this reason, it takes the viewer's discretion to apply this circuit on to car or motorcycle.

The purpose of the flashing brake light is to make it more visible. Because the tail lamp (rear light) has the same red color as the brake light. Some manufacturers such as Mercedes Benz, Volvo, BMW, Honda have applied brake light that can flash on several models of car and motorbike.

Currently at the rear end the Formula One (F1) race car, there is a flashing red light. That flashing red light is activated when conditions are critical (such as: rain, fog), or when the car harvests electric power from the wheel (kinetic energy) to charge the battery in the turbo hybrid system. Charging the battery will make the car slow down and be used when entering the bend, similar to braking technique by engine brake. Furthermore, battery power will be used for acceleration, such as when exiting a bend.


Thursday, November 22, 2018

Flasher Lampu Rem Berkedip Frekuensi Disetel


Rangkaian flasher lampu rem elektronik sederhana ini menggunakan relay yang dikontrol oleh transistor agar frekuensinya bisa disetel dengan mudah dengan trimpot (trimmer potensiometer). Lihat video saat rangkaian diuji frekuensinya.


Lihat juga video saat sirkuit dipasang pada lampu rem ke tiga pada mobil, atau lampu rem tengah.



Berikut adalah daftar komponen dari rangkaian yang sederhana dan murah namun efektif sebagaimana skema di atas.

R = relay 5 kaki SPDT (Single Pole Double Throw) 12 volt
D = dioda 1N4007
T = transistor BC109C
Rb = trimpot 10 kiloohm
Rc = resistor 120 kiloohm
C = kondensor 33 mikrofarad 25 volt
B = lampu rem

SPDT Relay (R) dengan lima kaki. SPDT adalah singkatan dari Single Pole Double Throw. Dua kaki dari relay digunakan untuk mengaktifkan solenoid, dan tiga kaki lainya sebagai saklar. Kaki NC (Normally Closed) terhubung saat relay mati, kaki ini terhubung ke lampu dan menyuplai arus ke kondensor (C).

Flasher relay ini akan menyalakan lampu jika relay tidak aktif. Relay akan aktif saat tegangan kondensor di atas 0,6 volt. Jika relay aktif maka arus ke lampu dan kondensor akan terputus, karena relay menghubung ke kaki Normally Open (NO). Lampu akan mati. Kondensor akan menyuplai arus ke basis transistor, transistor menghubungkan solenoid ke negatif. Sehingga relai akan aktif beberapa saat, dan lampu tetap mati. Jika tegangan kondensor lebi rendah dari 0,6 volt, maka transistor memutus arus  dan solenoid relai akan mati. Selanjutnya kaki NC akan terhubung kembali, lampu menyala dan kondensor terisi kembali. Maka siklus akan berlanjut.


Tampak pada foto rangkaian, relai 12 volt berwarna oranye dengan merk Schrack tipe TN313012. Relai ini dapat mengalirkan arus searah sebesar maximal 7 ampere. Jadi untuk 12 volt maka daya maximal beban, dalam hal ini lampu, adalah = 12 x 7 = 84 watt.

Dioda (D) berfungsi untuk menghilangkan tegangan tinggi (spike) yang timbul saat arus ke solenoid terputus. Spike ini dapat merusak transistor. Spike timbul karena runtuhnya medan magnet di solenoid menginduksikan tegangan tinggi dengan arah arus yang kebalikan arus suplai. Itulah sebabnya dioda dipasang terbalik.

Transistor BC109C dari jenis NPN, akan mengalirkan arus dari solenoid relay ke negatif jika tegangan di kaki basis di atas 0,6 volt. Transistor ini mempunyai bodi metal, sehingga kalau kepanasan maka dapat dipasang pendingin. Dari hasil test temperatur transistor tidak naik sekalipun flasher diuji selama beberapa jam.

Trimpot (Rb) dengan nilai 10 kiloohm akan menentukan lamanya waktu pengosongan kondensor. Sehingga menentukan lamanya waktu relay aktif dan lampu mati. Maka frekwensi dapat berubah saat trimpot ini disetel. Semakin besar nilai Rb maka semakin lama pengosongan kondensor, semakin lama lampu mati, dan frekwensi semakin rendah.

Resistor (Rc) berukuran 120 kiloohm menentukan lamanya waktu pengisian kondensor. Dengan kata lain menentukan lamanya relay tidak aktif dan lampu menyala. Semakin besar nilainya maka makin lama lampu menyala. Resistor ini juga menentukan besar arus yang disuplai ke basis transistor. Sehingga menentukan juga besar arus yang disuplai ke solenoid relay. Jika arus relay terlalu kecil maka relay sulit untuk diaktifkan. Dari hasil test diketahui bahwa Rc senilai 330 kiloohm akan membuat relay sulit untuk diaktifkan.

Sebenarnya Rc juga dapat diganti trimpot agar dapat disetel. Tapi terlalu banyak setelan juga dapat merepotkan. Transistor juga memiliki batasan arus basis maximal, sehingga jika Rc diganti trimpot maka beresiko arus maximal basis terlampaui dan transistor rusak.

Kondensor (C) senilai 33 mikrofarad menentukan lamanya lampu menyala, sekaligus juga menentukan lamanya lampu mati. Semakin besar nilainya maka frekwensi akan semakin rendah.

Lampu rem (B) tersambung pada kaki Normally Close (NC) dari relay. Jika sistem tidak bekerja, maka lampu rem akan tetap menyala tapi tidak berkedip. Jadi dengan desain ini, masih aman untuk mobil atau motor yang menggunakan sirkuit ini, meskipun flasher ini tidak berfungsi dengan baik.

Pada video tampak adanya lampu LED sebagai indikator. Jika ingin menambah lampu LED 5 mm tersebut maka cukup disambung pada kaki relay dengan menggunakan resistor dengan nilai sekitar 2,2 kiloohm sudah cukup terang sinarnya. Pemasangan LED dapat dibaca juga pada artikel flasher relay sederhana.

Input tegangan 12 vdc disambung ke kabel positif dari lampu rem, atau kabel positif dari switch pedal rem.

Rangkaian ini juga dapat diaplikasikan sebagai flasher lampu sein (lampu belok). Cara mudah membuat Printed Circuit Board (PCB) dari rangkaian ini dapat dibaca pada artikel membuat PCB tanpa kimia.

Lampu rem berkedip adalah teknologi yang masih sangat baru. Sehingga peraturannya masih rancu di beberapa tempat. Untuk itu dibutuhkan kebijaksanaan pemirsa dalam menerapkan rangkaian ini pada mobil ataupun sepeda motor.

Tujuan lampu rem berkedip agar lebih terlihat. Karena lampu malam (lampu belakang) juga berwarna merah yang sama dengan lampu rem. Beberapa pabrikan seperti Mercedes Benz, Volvo, BMW, Honda sudah menerapkan lampu rem yang dapat berkedip pada beberapa model mobil dan sepeda motor.

Saat ini di belakang mobil balap formula satu (F1) dilengkapi lampu merah berkedip yang diaktifkan ketika kondisi agak berbahaya (seperti: hujan, kabut), atau ketika mobil memanen daya listrik dari putaran roda (energi kinetik) untuk mengisi baterai pada sistem turbo hybrid. Pengisian baterai akan membuat mobil melambat dan digunakan seperti saat memasuki tikungan, mirip teknik rem dengan engine brake. Selanjutnya tenaga baterai akan digunakan untuk akselerasi, seperti saat keluar dari tikungan.

Wednesday, November 7, 2018

Depok Antasari (Desari) Toll Section Brigif Cilandak



The following video when driving from Brigif to Cilandak, then to Antasari road towards Blok M. The vehicle speed in the video is faster about 1.5 times of the actual speed. From Brigif direction, the operational gate is only Cilandak gate. Later there will be a gate towards Pondok Labu or Andara.



The Depok Antasari toll road (Desari) is already operational since it was inaugurated by President Joko Widodo on Thursday September 27, 2018, for section IA, the Antasari-Brigif section with a length of 5.8 km at toll gate Cilandak Utama, South Jakarta. The project Depok-Antasari toll road with a total of 21.6 kilometers is planned to be connected with the Bogor Ring Road toll road to Ciawi, with the addition of 6.5 kilometers of Bojonggede-Salabenda. So that it is expected to reduce the density on the Jagorawi toll road (Jakarta Bogor Ciawi).

The following video is showing a test drive from Antasari road and enter via Cilandak toll gate, then exit at Brigif. When the video was recorded, this toll road only reached Brigif. From the direction of Cilandak, the exit to Pondok Labu, Andara and Ciganjur is already operating. This exit is close to Green Andara Residence real estate.





KMToll GatesAdjacent ToDestination
0Antasari InterchangePangeran Antasari roadCipete, Blok M (north)
Jakarta Outer Ring RoadFatmawati, Pondok Indah, Jakarta-Serpong (west) toll
TB Simatupang roadMampang Prapatan, Pasar Minggu, Jagorawi (east) toll
1Cilandak UtamaMain toll gate Desari
3AndaraAndara roadAndara, Pondok Labu, Ciganjur
5BrigifBrigif roadCiganjur, Gandul, Cinere
8Krukut InterchangeCinere-Jagorawi tollCinere, Pamulang, Serpong-Cinere (west) toll
Kukusan, Margonda, Cisalak, Cimanggis-Cibitung (east) toll
13SawanganSawangan roadSawangan, Mampang, Parung
21BojonggedeTegar Beriman II roadBojonggede, Tajur Halang, Cibinong




Friday, November 2, 2018

Tol Depok Antasari (Desari) seksi Brigif Cilandak


Video berikut berkendara dari jalan Antasari menuju gerbang Cilandak, selanjutnya keluar di Brigif. Pada saat video direkam jalan tol ini hanya sampai Brigif. Dari arah Cilandak, pintu keluar ke arah Pondok Labu, Andara, dan Ciganjur sudah beroperasi. Pintu ini dekat dengan yang dekat dengan perumahan Green Andara Residence.


Jalan tol Depok Antasari (Desari) sudah dapat digunakan sejak diresmikan oleh Presiden Joko Widodo di hari Kamis 27 September 2018, untuk seksi IA, ruas Antasari-Brigif sepanjang 5,8 km di gerbang tol Cilandak Utama, Jakarta Selatan. Proyek jalan tol Depok-Antasari sepanjang total 21,6 kilometer direncanakan akan terhubung dengan tol Bogor Ring Road sampai Ciawi, dengan penambahan Bojonggede-Salabenda sepanjang 6,5 kilometer. Sehingga diharapkan akan mengurangi kepadatan di jalan tol Jagorawi (Jakarta Bogor Ciawi).

Baca juga Jakarta - Bogor via kereta rel listrik (KRL).

Video berikut saat berkendara dari Brigif menuju Cilandak, selanjutnya ke jalan Antasari ke arah Blok M. Kecepatan kendaraan pada video lebih cepat sekitar 1,5 kali kecepatan sebenarnya. Dari arah Brigif sementara ini hanya gerbang Cilandak yang aktif. Nantinya akan ada gerbang Pondok Labu atau Andara .



KM Gerbang Tol Berbatasan dengan Menuju
0 Antasari Interchange Jalan Pangeran Antasari Cipete, Blok M (utara)
Jalan Tol Lingkar Luar Jakarta Fatmawati, Pondok Indah, Jalan Tol Jakarta-Serpong (barat)
Jalan TB Simatupang Mampang Prapatan, Pasar Minggu, Jalan Tol Jagorawi (timur)
1 Cilandak Utama Gerbang tol utama Jalan Tol Desari
3 Andara Jalan Andara Andara, Pondok Labu, Ciganjur
5 Brigif Jalan Brigif Ciganjur, Gandul, Cinere
8 Krukut Interchange Jalan Tol Cinere-Jagorawi Cinere, Pamulang, Jalan Tol Serpong-Cinere (barat)
Kukusan, Margonda, Cisalak, Jalan Tol Cimanggis-Cibitung (timur)
13 Sawangan Jalan Raya Sawangan Sawangan, Mampang, Parung
21 Bojonggede Jalan Raya Tegar Beriman II Bojonggede, Tajur Halang, Cibinong


Thursday, November 1, 2018

Brake Light & Turn Signal Electronic Flasher


Flashing brake light is now popular. The purpose of the flashing brake light is to make it more visible. Because the tail lamp (rear light) has the same red color as the brake light. Some manufacturers such as Mercedes Benz, Volvo, BMW, Honda have applied brake light that can flash on several models of car and motorbike.

Currently at the rear end the Formula One (F1) race car, there is a flashing red light. That flashing red light is activated when conditions are critical (such as: rain, fog), or when the car harvests electric power from the wheel (kinetic energy) to charge the battery in the turbo hybrid system. Charging the battery will make the car slow down and be used when entering the bend, similar to braking technique by engine brake. Furthermore, battery power will be used for acceleration, such as when exiting a bend.

Read also simple adjustable twinkle light 2,200 watts.

The following simple and inexpensive electronic flasher circuit can be used to make flashing brake light. It can be applied to LED light or incandescent bulb.


R = relay 5 pins SPDT (Single Pole Double Throw) 12 volts
Dz = 12 volts zener diode 1 watt
C = condenser 470 microfarads 25 volts
R1 = 120 ohms 1 watt resistor
D = diode 1N4007
LED diameter of 5 mm
R2 = 1 kilo ohm 0.25 watts resistor
B = brake light


The following photo shows the composition of the components attached to the matrix board.



The following video on YouTube shows when the circuit prototype is being tested.



R is a relay SPDT with five pins. SPDT stands for Single Pole Double Throw. Two pins of the relay are used to activate the solenoid, and three other pins as a switch. NC (Normally Closed) pins are connected when the relay is off, this pin is connected to the lamp and supplies current to the condenser (C). Flasher relay will turn on the light if the relay is not active. The relay will be active when the condenser is almost full. If the relay is active, the current to the lamp and condenser will be disconnected, because the relay connects to the Normally Open (NO) pin. The lamp will turn off. The condenser will supply the current to the relay solenoid, so the relay stays active for a while, and the lamp stays off. If the condenser voltage is low, the relay solenoid will off. Then the NC pin will be connected again, the light is on and the condenser is recharged. Then the cycle will continue.

Seen in the circuit photo, 12 volt relay has orange color with Schrack brand type TN313012. This relay can transmit direct current for a maximum of 7 amperes. So for 12 volts the maximum power load, in this case the lamp, is = 12 x 7 = 84 watts.

Condenser (C) determines the blinking frequency. With a value of 470 microfarads will make a blink with a frequency of about 5 hertzs, or 5 blinks per second, suitable for flashing brake light. The frequency will also depend on the relay which is used.

With a value of 1,500 microfarads, flashing frequency is about 1.5 hertzs, suitable for turn signal (turn light). Because this flasher works with a solenoid (electromagnet), this flasher requires a negative wire. While the original flasher in a vehicle usually does not need a negative wire (ground), because it works based on heat due to the electric current that goes to the lamp. The original flasher is made of a bimetal that will disconnect the current when it is hot, and reconnect immediately after it's cooler. The turn signal lamp has a typical tick-tock sound due to the movement of the bimetal plate.


The zener diode (Dz) stabilizes the voltage at 12 volts. Because the voltage on a vehicle is usually unstable, and causes flashing frequency change. Zener and condenser also eliminate high voltage (spikes) that is produced in relay's solenoid when the relay is turned off. The spike voltage can damage the transistor and IC. Zener or condenser must always be installed when the relay is activated using an adapter with a transistor or IC voltage stabilizer. Pay attention to the above schematic and picture, zener is installed in reverse position. The cathode pin is connected to positive and the anode pin is connected to negative or ground. The current will flow from the cathode (K) to the anode (A) if the zener voltage is exceeded. This is why the zener to be used as a voltage stabilizer.

Resistor 1 (R1) connects the condenser (C) to negative (ground) when condenser is charging. The bigger resistant, the longer charging time for condenser, and the longer the lamp lights up. Conversely, if R1 is reduced, the length of time that the lamp lights up will be shorter. The current that passes through R1 also flows through the relay and activates the relay. If the R1 is too big then the relay will not be activated, because the current is too weak. Even though the condenser is full. From the test result, the biggest value of R1 is around 180 ohms, with this value the relay has begun to be difficult to activate.

The diode (D) prevents the current from the condenser to flow into the bulb (B) when the relay is activated. The current from the condenser can only go to the relay solenoid, in order to control relay activation.

LED light with a diameter of 5 mm is just an indicator, can be ignored. LED colors may be chosen according to your design.

Resistor LED (R2) to limit the current so that the LED will not damage. This resistor can be ignored if the LED is not installed. If the resistant is reduced then the LED will be brighter. For a diameter of 5 mm, usually the LED current must not exceed 20 milliamperes.

Lamp (B) is the vehicle's original brake light. Can be an incandescent lamp (bulb), or LED (Light Emitting Diode) light.

In my opinion, the flashing brake light should not be used on the brake light that are adjacent to the turn signal. Because it can be ambiguous when viewed at a glance by other drivers at high speed. The best position for the flashing brake light is on the third (3rd) brake light, or the brake light in the center at the back of the car. Some motorbikes have turn signal light with stem and separated from the brake light, so it can prevent confusion if the brake light is blinking.

Hopefully the reader applies this circuit wisely.

Wednesday, October 10, 2018

Flasher Lampu Rem Berkedip dan Lampu Sein


Sekarang sedang populer lampu rem yang dapat berkedip. Tujuan lampu rem berkedip agar lebih terlihat. Karena lampu malam (lampu belakang) juga berwarna merah yang sama dengan lampu rem. Beberapa pabrikan seperti Mercedes Benz, Volvo, BMW, Honda sudah menerapkan lampu rem yang dapat berkedip pada beberapa model mobil dan sepeda motor.

Saat ini di belakang mobil balap formula satu (F1) dilengkapi lampu merah berkedip yang diaktifkan ketika kondisi agak berbahaya (seperti: hujan, kabut), atau ketika mobil memanen daya listrik dari putaran roda (energi kinetik) untuk mengisi baterai pada sistem turbo hybrid. Pengisian baterai akan membuat mobil melambat dan digunakan seperti saat memasuki tikungan, mirip teknik rem dengan engine brake. Selanjutnya tenaga baterai akan digunakan untuk akselerasi, seperti saat keluar dari tikungan.

Sirkuit elektronik flasher sederhana dan murah berikut ini dapat digunakan untuk membuat lampu rem berkedip. Bisa diaplikasikan pada lampu LED maupun lampu pijar (bohlam).


R = relay 5 kaki SPDT (Single Pole Double Throw) 12 volt
Dz = dioda zener 12 volt 1 watt
C = kondensor 470 mikrofarad 25 volt
R1 = 120 ohm resistor 1 watt
D = dioda 1N4007
LED  diameter 5 mm
R2 = 1kiloohm resistor 0,25 watt
B = lampu rem

Foto berikut memperlihatkan susunan komponen yang terpasang pada papan matrix.



Video di YouTube berikut memperlihatkan saat prototipe rangkaian sedang diuji-coba.



SPDT Relay (R) dengan lima kaki. SPDT adalah singkatan dari Single Pole Double Throw. Dua kaki dari relay digunakan untuk mengaktifkan solenoid, dan tiga kaki lainya sebagai saklar. Kaki NC (Normally Closed) terhubung saat relay mati, kaki ini terhubung ke lampu dan menyuplai arus ke kondensor (C). Flasher relay ini akan menyalakan lampu jika relai tidak aktif. Relay akan aktif saat kondensor hampir penuh. Jika relay aktif maka arus ke lampu dan kondensor akan terputus, karena relay menghubung ke kaki Normally Open (NO). Lampu akan mati. Kondensor akan menyuplai arus ke solenoid relai, sehingga relai tetap aktif beberapa saat, dan lampu tetap mati. Jika tegangan kondensor sudah rendah, maka solenoid relai akan mati. Selanjutnya kaki NC akan terhubung kembali, lampu menyala dan kondensor terisi kembali. Maka siklus akan berlanjut.

Tampak pada foto rangkaian, relai 12 volt berwarna oranye dengan merk Schrack tipe TN313012. Relai ini dapat mengalirkan arus searah sebesar maximal 7 ampere. Jadi untuk 12 volt maka daya maximal beban, dalam hal ini lampu, adalah = 12 x 7 = 84 watt.

Kondensor (C) menentukan frekuensi kedipan. Dengan nilai 470 mikro farad akan membuat kedipan dengan frekuensi sekitar 5 hertz, atau 5 kedipan per detik, cocok untuk lampu rem yang berkedip. Frekuensi juga akan bergantung pada relai yang digunakan.

Dengan nilai 1.500 mikro farad frekuensinya sekitar 1,5 hertz, cocok untuk lampu sein (lampu belok). Karena flasher ini bekerja dengan solenoid (elektromagnet), maka flasher ini membutuhkan kabel negatif. Sedangkan flasher orisinal pada kendaraan bermotor biasanya tidak membutuhkan kabel negatif (ground), karena bekerja berdasarkan panas akibat dilalui arus listrik yang menuju lampu. Flasher orisinal terbuat dari bimetal yang akan memutus arus ketika sudah panas, dan menyambung kembali segera setelah lebih dingin. Flasher lampu sein berbunyi tik-tok yang khas terjadi karena gerakan pelat bimetal tersebut.


Dioda zener (Dz) menstabilkan tegangan pada 12 volt. Karena tegangan pada kendaraan biasanya tidak stabil, dan menyebabkan perubahan frekuensi kedipan. Zener dan kondensor juga menghilangkan tegangan tinggi (spike) yang timbul saat relai berubah dari aktif menjadi mati. Tegangan spike dapat merusak transistor dan IC. Zener atau kondensor harus selalu terpasang saat relai diaktifkan menggunakan adaptor dengan transistor ataupun IC stabilisator tegangan. Perhatikan skema dan gambar di atas, pemasangan zener yang terbalik. Kaki katoda terhubung dengan positif dan kaki anoda terhubung dengan negatif atau ground. Arus akan mengalir dari katoda (K) menuju anoda (A) jika tegangan zener terlampaui, inilah yang menyebabkan zener digunakan sebagai stabilisator tegangan.

Resistor 1 (R1) menghubung kondensor (C) ke negatif (ground) saat pengisian kondensor. Semakin besar resistansi maka akan semakin lama pengisian kondensor, dan makin lama lampu menyala. Sebaliknya jika R1 dikecilkan maka lamanya waktu menyala lampu semakin sebentar. Arus yang melalui R1 juga melalui relai dan akan mengaktifkan relai. Jika R1 terlalu besar maka relai tidak akan bisa aktif karena arus terlalu lemah, walau kondensor sudah penuh. Dari test yang dilakukan, nilai terbesar R1 adalah sekitar 180 ohm, dengan nilai ini relai sudah mulai sulit untuk aktif.

Dioda (D) mencegah arus dari kondensor mengalir menuju lampu (B) saat relai aktif. Arus dari kondensor hanya boleh menuju solenoid relai, guna mengkontrol aktivasi relay.

Lampu LED berdiameter 5 mm adalah indikator saja, dapat diabaikan. Warna LED boleh memilih sesuai selera.

Resistor LED (R2) untuk membatasi arus agar LED tidak putus. Resistor ini bisa diabaikan jika LED tidak dipasang. Jika resistor dikecilkan maka LED akan semakin terang. Untuk ukuran diameter 5 mm, biasanya arus LED tidak boleh melampaui 20 miliampere.

Lampu (B) adalah lampu rem orisinal kendaraan. Bisa berupa lampu pijar (bohlam), maupun lampu LED (Light Emitting Diode).

Menurut saya sebaiknya flasher lampu rem tidak digunakan pada lampu rem yang berdampingan dengan lampu sein. Karena dapat rancu jika dilihat sekilas oleh pengemudi lain saat kecepatan tinggi. Posisi terbaik untuk lampu rem berkedip adalah pada lampu rem ke 3, atau lampu rem di tengah, di belakang mobil. Beberapa sepeda motor menggunakan lampu sein yang menggunakan tangkai dan terpisah dari lampu rem, maka bisa mencegah kerancuan jika lampu rem berkedip.

Harap pembaca menerapkan rangkaian ini secara bijaksana.




Saturday, September 15, 2018

Busway TransJakarta Koridor 13 Mayestik Stop


Photo below shows Mayestik stop of TransJakarta busway koridor 13. Photo was taken on April 2017 from roof top of Mayestik Market. This market is famous with fancy textile, fabric, and clothing, with affordable price. Accommodations nearby are Everyday Smart Hotel Mayestik (2-star hotel), Veranda Hotel At Pakubuwono (4-star hotel).

Read more detail about TransJakarta Blok M-Ciledug koridor 13.

From Blok M to Puri Beta 2 (Ciledug) housing, the bus stops at: Tirtayasa, Tendean, Mayestik, Kebayoran Lama, Seskoal, Cipulir, Budi Luhur University (Adam Malik).




Foto di atas menunjukkan pemberhentian (halte) Mayestik dari busway koridor 13 TransJakarta. Foto diambil pada April 2017 dari puncak atap Pasar Mayestik. Pasar ini terkenal dengan tekstil, kain, dan pakaian mewah, dengan harga terjangkau. Akomodasi di dekat sini adalah Everyday Smart Hotel Mayestik sebuah hotel berbintang 2, Veranda Hotel At Pakubuwono (4-star hotel).

Baca juga detail lebih lanjut tentang TransJakarta Blok M-Ciledug koridor 13,.

Dari Blok M ke perumahan Puri Beta 2 (Ciledug), bus berhenti di: Tirtayasa, Tendean, Mayestik, Kebayoran Lama, Seskoal, Cipulir, Universitas Budi Luhur (Adam Malik).



Thursday, August 16, 2018

Rear Wheel Bearing Installation, Honda Car


This article is a continuation of the article on how to replace the rear wheel bearings with the type of wheel hub assembly (WHA). This WHA type bearing is easy to install, no need bearing press tool. This bearing is often referred to as: hub assembly, wheel hub unit, wheel hub bearing.

Read also about how to check the sound of a wheel bearing by turning the wheel by hand.


Clean spindle (axle), Anti-lock Braking System (ABS) magnetic sensor as indicated by the arrow in the above photo, and surrounding area. Soapy water can be used, then rinse with clean water.



The installation procedure for wheel hub assembly can also be seen on YouTube video.



As the above photo, install the new wheel hub assembly (WHA) bearing by inserting the axle into the bearing hole, then push the bearing by hand until stopped. No need to be pressed by special tool.



Attach the axle nut, usually can be easily rotated by hand until the bearing is steady.


Tighten the axle nut by socket wrench with 3/4 inch handle. Tighten to torque specification that is suggested by bearing manufacturer.

For Honda City, Fit, Jazz torque for rear wheel spindle nut is 134 ft-lbs ft = 181 Nm = 18.5 kgf.m .
More details about axle nut torque specification for various brands and models of cars can be read in SKF bearing catalog brochure.



If a torque wrench is not available, the following torque principles can be applied. See the picture above, torque or moment or force moment is the force multiplied by the length of the arm.

If the arm is shortened by half (L), to ensure the torque is constant, the force must be increased 2 times (2F).

If the arm is extended 2 times (L + L = 2L), then for constant torque, the force is reduced to half (F).

Your weight can be used as a force. If your weight is 70 kg, it will produce a force of 70 kgf. So to get a torque of 18.5 kgf.m, it needs an arm length of:

        18.5 / 70 meters = 0.264 meters or equal to 26.4 centimeters.

So with a weight of 70 kg, if you step on the handle of the socket with a distance of about 26.4 centimeters from the center point of the nut or axle, with both feet raised from the ground, it will provide torque of 18.5 kgf.m.

To ensure accurate torque, the socket handle must be in a position close to level  to horizontal line or ground. If the handle position is not close level, the torque will be reduced. In the position of the handle perpendicular to the ground, the torque will be zero. Do not jerk your feet when stepping on the socket handle. If the socket is easily detached from the nut, it is necessary to ask for help from another person (helper) to hold and ensure that the socket is still holding the nut, when the socket handle is stepped on.

More details about the principle of torque or moment of force can be read on the wikipedia page.



Install the brake drum by pushing it by hands, after wheel stud bolts are aligned into holes on the brake drum, like mounting the wheel.


As you can see in the photo above, 2 wheel nuts are installed to protect the wheel stud bolts if the hammer is missed. Using a screwdriver or a center punch with a hammer to make a notch on the spindle nut to lock the nut.


In the photo above, a notch has been made on the nut. Make sure the notch is deep enough to avoid the nut to rotate or loosen.


Attach the nut cap by pressing it by hand. Then install the wheel, jack stand and jack can be removed. Work has been completed.