Scott shows you how to modify a PC sound card to allow D.C. voltage measurements, he writes –
A PC Sound Card typically contains a sixteen bit ADC (or two if capable of capturing in stereo) which is used to digitise A.C. signals in the audio frequency range. In its typical audio application the ADC is intentionally isolated from any D.C. applied to input ports by series capacitance and so cannot be used to capture D.C. This page describes a general method for modifying a PC sound card to permit the digitisation of D.C. signal levels allowing a sound card’s ADC to be used as the basis of a simple and accurate ground referred voltmeter with millivolt or better resolution.
MAKE:it – Electronic Makers Toolkit @ The Maker shed. Hand picked by our Makers this kit features everything you need to get started with electronic construction.
- Soldering Iron
- PCB Vise Panavise “Jr”
- Small (7.8″) DeSoldering Pump
- Soldering Stand with sponge
- 0.5lb 60/40 Solder
- Desoldering Braid
- Wire Cutters/Stripper
- Shear Cutters
- 7-Function 2000-Count Multimeter