switch one load off whilst switching on another

Thread Starter

gdallas

Joined Apr 25, 2012
74
under normal conditions my main load is R4, however when my PWM becomes capable of switching on my FET, and hence my lamp (R3) What would be the best way to siwtch off R4 at the point my FET swithces on to alow current to flow through R3. the loads will be matched in the final circuit, both 6 ohms.

thanks
 

Attachments

AnalogKid

Joined Aug 1, 2013
10,987
Without knowing anything about the needed response time, cross-conduction, etc., it's hard to say. Based on the information you're given, a simple frequency discriminator (missing pulse detector) driving a SPDT relay will work.

ak
 

Thread Starter

gdallas

Joined Apr 25, 2012
74
hi,

do not want to use relays. poewrfets or similar only. The frequency is constant, 100Hz. the fet shown switches on at around 50%, my thoughts were a a matched P channel FET but unsure if this would work and if it would, how to configure it,
 
Top