Sometimes the simplest hacks tin beryllium the astir utile oregon ingenious, and specified is the lawsuit with [Keri Szafir]’s method of ensuring that potentiometers utilized successful audio devices are matched. If you see a emblematic stereo amplifier for a moment, you’ll spot 2 amplifiers successful 1 container with a azygous measurement control. Two channels, 1 knob? Volume knobs are ganged stereo potentiometers.
All potentiometers are not created equal, and peculiarly successful the cheaper devices they whitethorn not person a consistently matched absorption crossed some pots and crossed their travel. This messes up the stereo balance, truthful people it’s worthy selecting a portion with bully matching. [Keri] selects them not with his aureate ears, but by wiring some pots unneurotic arsenic a Wheatstone bridge. A metre betwixt the 2 wipers would observe immoderate existent owed to a mismatch.
A Wheatstone span is 1 of those useful circuits that has plenty of uses successful some AC and DC measurements. We astir apt spot them astir often in a strain gauge.