bogdanserban
Newbie level 4
I'm building a current sense circuit that uses a current transformer and triggers the SD pin of the SG3525 controller at a set current value.
The chip terminates the outputs at a minimum of 0.7V at the SD pin (which is normally pulled to ground). But it can also do pulse limiting if the overcurrent period is short.
I calculated the CT to produce 0.7V at 10A using the typical rectifier and resistor circuit. My question is how can this circuit be improved? Some used an SCR, triggered the gate with the CT voltage and pulled a reference voltage to the SD pin, other used more complicated circuits with transistors, zeners and stuff.
The chip terminates the outputs at a minimum of 0.7V at the SD pin (which is normally pulled to ground). But it can also do pulse limiting if the overcurrent period is short.
I calculated the CT to produce 0.7V at 10A using the typical rectifier and resistor circuit. My question is how can this circuit be improved? Some used an SCR, triggered the gate with the CT voltage and pulled a reference voltage to the SD pin, other used more complicated circuits with transistors, zeners and stuff.