Simple Passive Load With Measurement Points

image Over at his site Krzysztof Marcinek has a simple little project that should be of interest to anyone who is thinking about amplifier construction.   He has built an elegant and useful little tool.

A passive load is pretty much just a pair of resistors that emulate the impedance of a set of speakers.  They give you the benefit of being able to test an amplifier without fear of destroying or damaging your precious speakers. 

Because these passive loads are designed to take amplifier output sized voltages and current, the resistors have to be pretty hardy to avoid burning up.  Personally I use resistors with large aluminium clad resistors to load test my projects. 

My analogue scope is able to withstand large voltages, but Krzysztof is using a computer soundcard to conduct measurements.  In his design he includes a low voltage output by using a stereo variable resistor to divide the voltage from his test amplifier. 

What’s very impressive is the construction that Krzysztof has applied to what is for most a common tool. (my passive load is simply a CPU heat-sink with the resistors tie wrapped to it!).  Check out his site for more information…

DIY, audio, electronics...