Mosaic
Well-Known Member
Hi,
I am thinking of making two battery operated portable tools.
1) Tests for constant current ( up to 5A DC) or constant voltage up to 24 VDC and assesses loaded DC ripple/noise p-p, if possible down to 2 mV.
2) Tests audio capacitors for value & A.C. coupling noise/distortion.
For item 1) I suppose Linear Bipolar power transistors on a fan cooled processor heatsink can apply the 5A load.
An instrumentation OPA to amplify the ripple with a peak hold into a uC ADC to measure it with a precision Vref.
For Item 2:
I am not sure what is the best approach. I am wondering if I just rely on hearing to work. So I use a high quality reference capacitor into one side of a headphone and the output of the test cap into the other side with matched parts for volume and amplification from a standard 'source' material. Either a pure sinewave with variable freq. or an mp3 hifi source.
I am thinking of making two battery operated portable tools.
1) Tests for constant current ( up to 5A DC) or constant voltage up to 24 VDC and assesses loaded DC ripple/noise p-p, if possible down to 2 mV.
2) Tests audio capacitors for value & A.C. coupling noise/distortion.
For item 1) I suppose Linear Bipolar power transistors on a fan cooled processor heatsink can apply the 5A load.
An instrumentation OPA to amplify the ripple with a peak hold into a uC ADC to measure it with a precision Vref.
For Item 2:
I am not sure what is the best approach. I am wondering if I just rely on hearing to work. So I use a high quality reference capacitor into one side of a headphone and the output of the test cap into the other side with matched parts for volume and amplification from a standard 'source' material. Either a pure sinewave with variable freq. or an mp3 hifi source.