I'm wondering if there's a way to create a current controlled voltage source. At the moment I have a mosfet (NPN, PN2222) connected in series with a positive 5V terminal and ground. I control that mosfet using a ~2.5 V input voltage. What I wanted to do was create a 5V output when the mosfet is on. However, mosfets can only be connected in series, with the voltage on one end being necessarily higher than the other for it to turn on. Is there a way to output a voltage using only a mosfet, A 5V source, 3 volt source to turn on the mosfet, and ground? Basically, if the 3 Volt source is connected, output 5 volts, otherwise 0 V. I only have 2 diodes and 2 mosfets and a handful of resistors to use.
Something like that ^. Obviously that doesn't work because there's no voltage difference and so the mosfet doesn't turn on even when 3V is applied to it, and that's where I'm stuck.