April 18, 2015 - The shortcircuit test

A project log for Digital Bench Power Supply

A new design, made from scratch, for a digital bench power supply to offer regulated voltage and current, and prompt shortcircuit protection

Radu MotisanRadu Motisan 04/27/2015 at 14:460 Comments

So I tested it for the shortcircuit response time, and the result is that...

The response is ultra-fast!

Here are some nice oscillographs showing the quick recovery after a shortcircuit event. It takes less than 350ms to recover to the original voltage configured as shown in the second picture. The CH1 (Yellow) is connected to the output, and the CH2 (Cyan) is connected to the shunt. The first picture shows the quick voltage drop on output, and an increase on the shunt, as expected.

A few more tests shown that I can get 26V and 5Amps max with a TL082 and 31.5V and 4Amps max with the LM384, yet the latter is too close to its voltage limits.

All's done, I'll just update the project description with code and PCB details as well as pictures with my construction. Those of you interested in building one, feel free to ask any questions or send suggestions. Thanks for your interest!