I have done DC motor control with an H-bridge circuit before. I used a 3.6 V, 9000 mAh (ERC26500) battery and had no problems.
Now I want to use a latching solenoid and I need 7.2 V for that, so I will use 2 batteries in series. At the same time, I will regulate the 7.2 V voltage and reduce it to 3.3 V. This 3.3 V will power the STM32.
I had a problem when I made this circuit. The instantaneous current of the battery was not enough for the solenoid. That's why I added an ultra capacitor to the circuit. After adding the capacitor, the solenoid started working without any problems. However, while the solenoid is operating, it also draws some current from the battery and the STM32 does not receive enough power.
That's why I want to disconnect the battery and ultracapacitor before the H-bridge circuit works. So, the solenoid will only be fed from the ultracapacitor and the battery will continue to supply only the STM32.
I decided to use a depletion type MOSFET (Q1 in the schematic) so that the battery does not feed the solenoid. Is there any other method to break the connection between battery and capacitor for 1-2 seconds?