Re: 400V DC, high side P channel FET load switch with dealy
Hi,
If the 5 seconds isn't a precise value, an option could be as simple as removing the 10k*10uF capacitor from the BJT base and placing them on a 5-second monostable 555 circuit block and the 555 output into an inverter and that into the BJT base. Maybe too convoluted a solution with too many parts for you, understandable.
I think Klaus said it already, if that's what I think it is, that isn't a useful time delay circuit there, it's only a very slow turn-on - the opposite to what the MOSFET should see. Look for gate drive circuits, they're usually about reducing actual switching time to the minimum possible.