Designing a power failsafe system

Hi @rjehangir @model14 I am working on a custom asv and iam designing a failsafe system for it .My plan is to use a octocoupler(pc817) which will control the mosfets(IRF5305S) connected to the ESC( " Basic ESC" for T200 thrusters) . Do I need a diode for this circuit? (between mosfet and ESC),what diode should I use ?, am i using the right mosfet for the esc? I am begineer in this field and have little to no idea on how to solve this problem. I tried searching the internet but in vain I didnt get any answers or ideas to solve this problem.


Hi @SIVABHARATHI, welcome to the forum :slight_smile:

If you walk through the problem you’re trying to solve, the assumptions you’ve made, and your circuit design, we (the community) can potentially provide some feedback on that, but we can’t do electronic design work for you.

Beyond that, I don’t really understand what you’re intending to do here. An optocoupler provides physical isolation between a switching circuit and a load circuit, and your description implies you’d be using MOSFETs as the load (presumably with their outputs controlling the power supply connections for the ESCs?), but something still needs to control the switching circuit, which you haven’t mentioned in your post. Are you intending to have some kind of programmatic control, or a physical switch, or something else?