In one of my project I want to implement an Over Voltage + Over Current protection.
For Over Current I figured i'll just use a CB.
The Over Voltage I designed this way:
Source voltage goes into a voltage divider (2 resistors) and enters a comparator.
The second comparator input goes to a voltage reference (a zener diode).
The comparator output drives an npn transistor which drives the gate of a power mosfet.
The power mosfet is what switching the whole load which i want to protect to the ground or vcc (NMOS or PMOS).
I though of using a battery to power the comparator and zener, or perhaps use a 7805 to get 5v out of my power source. since the current used by the protection circuit is low I'd assume the 7805 won't need a heatsink.
How is the design ?
Is there a better way of doing it ?
Thanks in advance, Mike.
For Over Current I figured i'll just use a CB.
The Over Voltage I designed this way:
Source voltage goes into a voltage divider (2 resistors) and enters a comparator.
The second comparator input goes to a voltage reference (a zener diode).
The comparator output drives an npn transistor which drives the gate of a power mosfet.
The power mosfet is what switching the whole load which i want to protect to the ground or vcc (NMOS or PMOS).
I though of using a battery to power the comparator and zener, or perhaps use a 7805 to get 5v out of my power source. since the current used by the protection circuit is low I'd assume the 7805 won't need a heatsink.
How is the design ?
Is there a better way of doing it ?
Thanks in advance, Mike.