A few added components make a self-contained controller for 100A load

摘要

The late Jim Williams' last project was a 100A active load (Reference 1). That design needed a separate signal generator and other components. This Design Idea makes the load self-contained. It adds potentiometers to control the stepped load levels, a chopper oscillator to switch between the set load levels, and a dual-readout DPM (digital-panel meter) to allow for direct voltage and current readout. In tribute to Williams, it uses three Linear Technology chips. The heart of the load controller is two potentiometers, Set A and Set B (Figure 1). These devices allow you to set A and B load levels anywhere in the 0 to lOOA-load-range capability of Williams' design. For instance, assume that Set A is at -0.5V and Set B is at —0.75V.