Current sensed by power supply

Thread Starter

andrew74

Joined Jul 25, 2022
224
Hi!
Forgive the banality of the question I am about to ask, but being one of the first times to try out instruments of this type, I still lack basic knowledge, which I hope to find here.

I was feeding two resistors in parallel with a bench power supply (Rigol DP831). The display (the photo is an example from the internet) showed the voltage set by me and the current (and the power V*I).
Unfortunately I don't remember the value of the resistors and the voltage I set (I did a lot of tests) so I can't give a numerical example, but it's no need anyway for my question.
The current value shown in the display (under the voltage value set by me) indicates the total current flowing in the circuit? In other words, the red arrow in the schematic:

1681758895001.pngSmartSelect_20230417_211456_Samsung Notes.jpg

If I only wanted the current on one of the two resistors (without using ohm's law and calculations, but using only a multimeter) I would have to connect an additional multimeter in series with that resistor.

Am I wrong?
 

Ian0

Joined Aug 7, 2020
13,132
wrong-ish. You could simply disconnect the second resistor, and the power supply would tell you how much current was flowing in the first.
Or you could use a multimeter as you suggested.
 

Thread Starter

andrew74

Joined Jul 25, 2022
224
sbagliato-ish. Potresti semplicemente scollegare il secondo resistore e l'alimentatore ti direbbe quanta corrente stava fluendo nel primo.
Oppure potresti usare un multimetro come hai suggerito.
yes exactly, but with the two resistors in parallel (or whatever circuit it is) the current indicated by the power supply is the total current in the circuit, so for example with two resistors in parallel of 10ohm one and 100k the other .. the current indicated is the sum of the current on 10ohm and the current on 100k
Just to give an example
 
Top