Simple analysis to remote compensation of Programmable Power DC source

In practical application, resistance in cable cause voltage drop. It will cause the voltage reach to load side different from exact demand voltage which affect the accuracy of test. This situation is common in ATE test. To make up this situation, it need to remote measurement function of Programmable Power Supply to compensate the voltage drop in cable. APM Programmable DC Source is equipped with this function with higher security and easier to operate.

Under ideal conditions, there is no resistance in the cable between Power Supply and load. In fact, resistance in cable increasing is related to the length of cable and standard. When loop current flows through the wire, it will cause voltage drop which make the voltage of load lower than expectation. If power supply is set to output 3.3V/1A, resistance of output wire is 0.3 Ohm; there will be 0.3V voltage drop. Voltage reach to load side will become 3.0V. It make load unable to operate normally. Thus, it needs to compensate the wire. For that, customers do not need to worry about it on APM products as APM Programmable DC Source is equipped with remote compensation function. Remote compensation wire connects from power supply to load as remote compensation is high resistance circuit in power supply. Current on compensation wire is small. Voltage drop could ignore. Voltage of load could back to power supply control circuit via remote compensation wire. Power supply could adjust its output to compensate above voltage to make the voltage of load equal to setting voltage. It could reach the accuracy of test.