✦Step 1:-Bend the pin C of BD139 to the back, pin B was soldered to the 22K resistor together.
✦Step 2:-Solder the pin of BD139 to the negative pole of the variable resistor. The B-pin and 22K resistors are soldered to the variable pole of the variable resistor.
✦Step 3:-Follow the steps above to make three variable electronic devices.
✦Step 4:-Put three electronic devices in parallel with wires.
✦Step 5:-Connect the four wires on the RGB light strip to the top of the C pin of the three BD139, and connect the positive pole to the positive position of the variable resistor of the first BD139 device.
✦Step 6:-Connect the 12V power supply to the positive and negative poles of the variable resistor of the first DB139 device.
『BD139 transistor 』 view more ⇒https://www.utsource.net/itm/p/836289.html
『22k resistor』 view more ⇒https://www.utsource.net/sch/22k%20resistor
『RGB strip LED 』
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