digitally adjustable overcurrent protection

Thread Starter

rustynex

Joined Jul 26, 2019
7
Hi all,

I am trying to make a circuit that supplies a high current (maybe as high as 60A) and i want to monitor that current consumption and isolate the output in an overcurrent situation. but i would like to make the cut off point adjustable with a microprocessor. so effectively what it would be is a programmable virtual circuit breaker.

i have been looking at hall effect current sensors as well as shunt resistors, but i am trying to design something that uses minimal components, as well as being consistently reliable and fully solid state and maintaining a high efficiency.

the idea is that in the end the design can be multiplied to make a multi output programmable power distribution module

anyone have any useful pointers?
 

dl324

Joined Mar 30, 2015
8,849
Insert a current monitoring resistor upstream of the regulator and use a power MOSFET disconnect the input for over current conditions.

You'll get more specific suggestions if you provide a schematic.
 

Thread Starter

rustynex

Joined Jul 26, 2019
7
Insert a current monitoring resistor upstream of the regulator and use a power MOSFET disconnect the input for over current conditions.

You'll get more specific suggestions if you provide a schematic.
thanks for the reply, i don't have a schematic at the moment because i am still working on the basic design, but the idea was basically what you suggested that the system would be isolated with a MOSFET and current monitored either with a hall effect sensor or a shunt resistor. but the actual monitoring and isolation is the bit i am having trouble with. of course i could put a microprocessor in that simply reads the current value and then cuts power when a certain current is detected, but the issues with this is that if the processor locks up or doesn't respond fast enough, then electronics further down the line could be damaged. so i need something basic and passive like a circuit breaker, except digitally programmable and resettable from a microprocessor.

So what are the range of currents you want to adjust to?
thanks for the reply, i was thinking of having multiple outputs with different ranges, so there would be high current outputs which have high current circuit design, components and connectors etc, and that would be in the range of maybe 20 to 70 amps? but then i would have a range of low current outputs from 1 to 20 amps, and then some basically signal outputs from 10mA to 1A, these i could potentially protect with a PTC maybe?
 
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