Bigsby® is a registered trademark of Fender Musical Instruments Corporation.Big Bends®, String Sleeves™, G-String Wipes™, Fret Board Juice™, AXS Wipe™, and Encore Scratch remover™ are trademarks of Big Bends LLC.Belden® is a registered trademark of Belden Incorporated.Babicz® is a registered trademark of Babicz Design Ltd.Alpha® is a registered trademark of Alpha Products Inc.3M® is a registered trademark of The 3M Company.and are not to be represented as products of the following companies unless otherwise noted. WD replacement parts are made by or for WD Music Products, Inc. Kluson®, the Kluson logo, Kluson stylized K, Kluson pinstripes and logo / artwork design(s), are registered trademarks of WD Music Products, Inc.Īll other trademarks, service marks and trade names present on this site are trademarks or registered trademarks of their respective owners. It's not very useful though.WD®, the WD logo, and logo / artwork design(s), are registered trademarks of WD Music Products, Inc. It is possible to measure the potential to ground of an isolated battery with care, and a very, very high input impedance meter (often called an electrometer). You touching it (body resistance 100k) would get it to the same potential as you with a time constant of \$\mu S\$. Adding just a few nC of charge to it, as you might easily do by walking across a carpet with it, would change the potential by thousands of volts.Ĭonnecting it to another body using a resistance of 100Mohm (about the highest value of resistor whose accuracy won't be trashed by surface contamination if you touch it) would equalise the potentials with a time constant of mS. For instance, a 9v battery may have a capacitance to infinity of a few pFs. While each terminal of a 9v battery does have a potential with respect to a reference point at infinity, it's not a stable or useful potential, as it takes so little charge to change it. It's a definition of potential, but not a practical one. I do not understand how this relates to circuits. Wikipedia tells me that the electric potential of a point is the amount of energy needed to move a unit positive charge from a reference point, usually infinity, to that point. When debugging it is very often most convenient to attach the negative probe to the circuit ground and take all readings with reference to that point. Inverting the meter so that its positive lead is grounded will also result in a -9 V reading.įor most practical electronics you just need to work out the potential between points.Inverting the battery we now have a positive ground.Putting a medium resistance (say 100k) across the meter terminals will cause the reading to collapse to zero. Note that a very sensitive digital meter will show random readings due to stray electric fields.
Without a reference for the voltmeter it will read 0 V.This prevents floating of the device power supply and might be used for safety, to avoid audio hum, etc., depending on the application. We have the option of connecting the circuit ground to earth.One recent question on this site showed an old transistor radio circuit with the battery positive as the "ground". In most battery powered equipment this will be the DC negative supply. In this case some arbitrary point in the circuit has been taken as ground.
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