Transistor Switch Question

Thread Starter


Joined Oct 26, 2005
I am currently working on my senior project and am having a bit of trouble. Basically, I have a 10 Volt source that needs to be given to a piece of hardware whenever a 3.6 Volt source is activated. I am pretty sure I need to deal with transistors, but don't have much experience with them. Can anyone point me in the right direction, or draw a simple diagram showing how this might work?
Help is appreciated.

(switch lets +10V go through to output) <----- +3V
+10V (after switch turns on)


Joined Oct 13, 2005
You could also use complementary enhancement-type MOSFETs instead of BJTs. Using MOSFETs would require only two resistors to bias the gates of the MOSFETs to the off state.


10V_in --> source_of-pFET
drain_of-pFET --> 10v_out
drain_nFET ---> gate_of-pFET
10V_in ---> 100k_resistor ---> gate_of-pFET
(Vgs-threshold of pFET needs to be less than -1V but more than -7V)

ground--> source_of-nFET
3.6V_in ---> gate_of-nFET
ground ---> 100k_resistor ---> gate_of-nFET
(Vgs-threshold of nFET needs to be more than 1V but less than 3V)