SHORTS, voltage across resistor converts to current

[walters]

I tried it and it didn't work

I put the power supply at 0.5 volts at 1 amp

I put one of the power supply probes on the output pin of the regulator and I would use the other power supply probe to probe random components

Some of the components measurements would say
1.) 0.5 volts at 1 amp
2.) 0.5 volts at 0 amps
3.) 0.3 volts at 1 amp
4.) 0.2 volts at 1 amp

I got multiple components reading those types of values

Am I doing this right?

 

[sky_123]

You're experimenting without remembering what you're looking for. When on an unknown PCB, the idea is to
try and make sense of what components you're looking at, the tracks and what voltages you expect. You've got some measurements
listed, but you forgot the point of what you were looking for. If done correctly, you should be seeing a small decrease as the
track proceeds, but it sounds like your multimeter can only measure in multiples of 0.1v (100mV).
As a suggestion, here is a circuit that you can practise with. Why not construct it, and learn from it by purposefully putting in shorts,
and seeing the result. An alternative method is to run this circuit in a simulator.

Notice that the circuit has a simulated probe attached, which is showing you the voltage at that point. The current is also displayed,
so the simulator is giving you valuable training information.

Or, as a pencil-and-paper exercise, write a table containing the locations where there could be potentially shorts (all wires are
numbered in the circuit, e.g. 1A, 1B, 2A, etc..) and also the expected voltage at each point.
In other words, pretend you're attaching a probe like the one shown, at different points, and write down the expected voltages.
Maybe do it for the unadulterated circuit, and then for the same circuit with a short inserted in a location of your choosing.

Until you're 100% comfortable with this simple circuit (after all, it is just one transistor), you will find it extremely hard to understand
other circuits. This circuit is directly related to your job (i.e. looking for shorts in power supplies) so I hope you find it relevant.

EDIT: As an example, approximately what voltage do you expect there to be at point 2C in the circuit shown, under normal operation? (This is not
a trick question by the way). Point 2C is the output of the power supply.

 

[FvM]

You're experimenting without remembering what you're looking for.

Exactly. The discussion has been about methods to locate shorts. The recent measured values don't seem to be related to shorts (which would involve a large current at about zero voltage).

 

[rohitkhanna]

Good grief. All this for a homework assignment ???!!?

LoL !!