I wanted to use 12v led, so I tried to switching 5v(gpio pin) to 12v.
This is my 12v switching circuit.
And this circuit broke down my raspberry pi.
When I wired this circuit, they worked well. But I switched on and off several times, the transistor and raspberry pi broke down.
Why my raspberry pi and transistor died??
Best Answer
When those transistors are turned on, there's what amounts to a short circuit through the associated LED to ground. You need an appropriately sized resistor in series with those LEDs.
I suspect what happened (the failure mode you experienced) is that the transistors got damaged by overcurrent, and the failed transistor inadvertently fed 12V back into your GPIO pin and that baked your Pi.