I need to switch off a PNP transistor however, the voltage on the emitter side will always be larger than the base. Is there a way to switch the transistor off?
Edit: The aim is to maintain a constant voltage at the collector of Q2 of around 4.7V with a supply of between 10Vdc and 230Vac. I want to use Q3 to switch off Q2 by shorting the base of Q2 to supply when enough voltage is generated across R11. However it is never really switching off.
Any ideas please?
thank you for your time.
Best Answer
The PNP transistor can be turned on by maintaining a base voltage of
simulate this circuit – Schematic created using CircuitLab
so if you maintain the base voltage above (emitter_gnd volt - 0.7 volt) the transistor can be turned off