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.