Protecting the LTC3780 (or other DC/DC converter)
The main problem when playing with LTC3780 (or other) is it can fry easily. Especially when you are playing with the feedback loop. How so ? Easy, just disconnect the feedback pin, it will crank up the output voltage to the max and burn As a bonus, it will also fry what's connected to it if they don't like higher voltage. So here, we'll add a very simple protection circuit : An enable pin that turns the LTC off by default, i.e. if the signal is not driven A shutdown circuit if the output voltage exceeds ~ 28v The right side is glued to the DC/DC converter The left side is on the control board. If the Enable pin is high (or floating), the STBY pin is pulled down and the DC/DC turns off Similarly, if Vout exceeds ~ 26 V, STBY is pulled down, and the DC/DC turns off Very primitive, but that should help when connecting/disconnecting stuff all the time NB: If you use another N-FET (Q4), you'll have to change R9 to something else T