Reverse Engineer Power Board to avoid over-current is an proved effective method, use existing arc suppression circuits to provide over-current protection and consider 5V 2A and 12V 3A flyback power supplies circuit board gerber file design.
Reverse Engineer Power Board to avoid over-current is an proved effective method, use existing arc suppression circuits to provide over-current protection
One of the key specifications of the power supply is to provide over power protection (OPP) for the 5V output when the 12V output reaches no load or when the load is extremely light. Both of these two outputs have a voltage regulation requirement of ± 5%.
For the usual solution, the use of a sense resistor will reduce the cross-regulation performance, and the fuse is expensive. And now there are arc suppression circuits for over-voltage protection (OVP). This circuit can meet the OPP and voltage stabilization requirements at the same time, and this function can be realized by using part of the arc suppression circuit which can be seen from below Figure
This circuit can meet the OPP and voltage stabilization requirements at the same time, and this function can be realized by using part of the arc suppression circuit
that R1 and VR1 form a 12V output active dummy load, so that 12V voltage regulation can be achieved when the 12V output is lightly loaded. When the 5V output terminal is overloaded, the voltage on the 5V output terminal will drop.
The dummy load will draw a lot of current and voltage drop across R1 can be used to detect this large amount of current. Q1 turns on and triggers the OPP circuit.
