Load test control circuit diagram
FIG load test is a control circuit. This external load circuit up to 10A, widely used in the drive test power, the power amplifier, LED solenoids and relays, and the carrying c
apacity of the experiment. General resistive load different, it by a 1.2 50V voltage range adjustment load current to maintain a constant load test. Circuit power MOS-FET (VTl) and the sense resistor (RA a RD) load power consumption, battery used to isolate and solve the problem of grounding. RP2 10-turn potentiometer, improve the accuracy and resolution. Wiper RP2 for Al provides a reference voltage through feedback to ensure prosperous wiper voltage present on R5, forcing the required load current through the VT1. Al bias current (up to 3nA) via an RD series resistor RA circulation, the current times and four resistors (100 obtained 30OnV error voltage. This compared with the error voltage to provide the noninverting input of A1 by the voltage RP2 is small, negligible .Cl for enhancing stability, RA RD series resistor can be a 4 range of output current. During calibration, access the battery and the circuit, and then access 5V/l0A power as experimental load RL. In RP2 for the next full-scale, adjusting RPl and read the exact 10 OOA current with ammeter. In order to check the linearity of the circuit, to accurately adjust the RP2, and reads 5, OOA current with ammeter. RB RD adjust a resistance calibration to the rest of the current range.