2 isolated circuits touching

Thread Starter

Apgar426

Joined Apr 25, 2020
1
Newbie curiosity question here - I have 2 separate battery chargers plugged into my wall - both putting out 58v DC. If I touched the positive wire of one output to the positive of the other, would anything happen? Why or why not? What if they were different voltages?
 

danadak

Joined Mar 10, 2018
4,057
Depends on the architecture. But yes a good possibility large current would
flow between them even with small voltage differences.

You could try it using a R, like 2 - 10 ohms, and seeing how current goes between
them constrained by the R. If you dont have a low ohm R take some wire and create one.
Online are tables of R/foot versus gauge so you know how long to make it. Mount wire
carefully as it may get very hot.


Regards, Dana.
 

dl324

Joined Mar 30, 2015
10,758
have 2 separate battery chargers plugged into my wall - both putting out 58v DC. If I touched the positive wire of one output to the positive of the other, would anything happen?
We need to know more about the power supplies. Are the outputs isolated from line voltage?
 

Reloadron

Joined Jan 15, 2015
5,456
I have 2 separate battery chargers plugged into my wall - both putting out 58v DC. If I touched the positive wire of one output to the positive of the other, would anything happen? Why or why not? What if they were different voltages?
I don't know. Maybe yes and maybe no as to anything happening. Do they have isolated outputs? Two separate battery chargers tells us absolutely nothing about them. Before anyone can say what may or may not happen one should know the actual circuitry. My answer is absolutely, definitely, maybe.

Ron
 

DJL33B

Joined Mar 13, 2020
2
DC current flows through a complete circuit connected across a difference in voltage. The amount of current depends on voltage and load resistance. Too much current causes dangerous failures.
If there is no complete circuit there will be no current flow.
If there is no difference in voltage there will be no current flow.
Un-connected negative leads, i.e. no complete circuit, will result in no current flow, and attempting to measure voltage may result in erratic or inaccurate readings.

When trying this with unknown internal circuits, I connect standard light bulb(s) between the devices, and measure the voltage across the light bulb(s). If there is no voltage across the light bulb(s) there is no current flow.

There are many online sources for learning basic DC circuits that will help you understand.
 
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