Hi
I'm looking to design a circuit that allows me to supply 12V power from a DC to DC inverter. The aim of the design circuit is to use as little power as possible whilst it is switched on. There will be an overall kill switch on the DC-DC converter that will be used when this circuit is not required for large periods of time, therefor a small amount of power use when this circuit is in an OFF state is acceptable as most of the time after engaging into the OFF state the converters kill switch will be turned OFF. There are a few requirements of the circuit though.
It needs one ON push button and two OFF push buttons that need to be wired up such that they are isolated from the circuit and are incapable of delivering more than 50mA of current. (The switches will be placed a few meters away from the circuit but cannot carry greater than 50mA of current due to regulations that apply to the design.
My designs so far for this are to use a high resistance to pull up the switches as seen in the attached images.
(The 1K resistors are placeholders until I calculate the optimal resistance)
I have a working design for the circuit however it I have tried multiple ways of using the out signal with another MOSFET or two to latch the first P channel MOSFET on without any success.
I've looked at EEVblog's video: EEVblog #262 - World's Simplest Soft Latching Power Switch Circuit
https://youtu.be/Foc9R0dC2iIHowever I'm unsure on how to do this in conjunction with the requirements of the switches and pulling them up.
Does anyone have any suggestions on how I could design this circuit?
Sorry if my explanation is confusing I'm a newbie to the forum.
Thanks in advanced.