DC power monitor

This circuit is used to detect whether the DC power supply is working in an overload state or an undercurrent state. When the load is overloaded for some reason , the current
of the power supply will increase significantly, which may lead to failure if not handled in time. As shown in the figure, when the load current reaches 65% of the full load, the circuit will send out an alarm signal.     The DC power supply is applied to the load through the small resistor Rx. When the voltage generated on Rx is applied to the ② and ③ pins, a current is formed inside the RCV420. The value of Rx is mainly determined by the load current. The relationship between them is Rx =75/ (//16rn_A -1).     For example, assuming that the maximum current of the DC power supply is 1= 1A=lOOOmA, then Rx=75/( 1000/16-1) : 1. 22(n). Therefore, after the current flowing through Rx is converted by RCV420, a voltage of O-5V is output. ⑥. @ pin output IO. OOV reference voltage, given by R]. R3 divides the voltage to get Va=3.2V, "=2.2V, which are added to the voltage comparator LM193/393 respectively . When the output voltage of RCV420 is greater than the Al (one) terminal potential, Al outputs high level; when the output voltage of RCV420 When the potential is greater than the A2(+) terminal, A2 outputs low level and the LED lights up; changing the resistance of Ri~R3 can change the current control point.