Power Efficient Circuit
Greetings,
I need to operate 40 independent Relays(12V 250mA each) through a single circuit.
To turn them ON, 12V supply is required.
To keep them ON, 4V supply is the minimum requirement.
Since these relays remain ON for long duration of time I need to make a circuit that provides 12V for about 0.1ms (to turn on relay) and then provide 4V (to keep them on).
Currently I'm using IRFZ44N MOSFETS (controlled switching through 74HC595) that are continuously providing 12V to the relays to keep them ON.
Thus a lot of power is being wasted.
Kindly Advice.
Thank You.
1 Answer
This is a poor circuit. Panasonic offers relays that operate at logic levels of 5 volts and as low as 3 volts. In addition 250 mA for each is ENORMOUS as there are latching relays that consume ZERO current once latched. My recommendation is to read up on relay datasheets from many manufacturers and figure out a low to do this with LOW voltage and little to NO current (once latched). Also there is no need for MOSFETs since a simple MCU can support the latching current for the coils. - - - As the saying goes - KEEP IT SIMPLE STUPID (KISS)
