This is a question I saw in another electronics forum. Although it is a simple question, I am still thinking there could be a simpler solution from the one I found.
The question goes like this: We have digital logic pulses going from 0 to 3.3V. We want them to be from 0 to -12V.
The solutions I thought of include using some kind of "isolation": Charge pump (capacitors), transformer or optocoupler. I actually simulated a solution using an optocoupler in Proteus and it works well.
My question is, can it be done only with transistors, without isolation components?
