In article ,
"Costas Vlachos" wrote:

"Watson A.Name - 'Watt Sun'" wrote in message
.. .
I got tired of switching the leads of my DMM. Suddenly if dawned on
me that I can just set the power supply to 10.0V for exaample, and
read the current, and then divide the voltage by the current to find
the resistance. Like I put a resistance on the PS, it reads 10.0V and
the current is .018A, so 10 / .018 gives 555.6 ohms. Must be a 560
ohm resistor.

I turned my PS into an ohmmeter - FREE!

Hee-hee - Work smarter, not harder!

Of course, make sure the current stays low so the resistance doesn't
overheat. For low resistances use a volt or less.



Yep, that's how ohmmeters work actually. I'm currently designing a digitally
controlled PSU which includes a dot-matrix LCD that shows a lot of info
about the state of the PSU. For e.g., it multiplies V * I so the user can
see the load power in real-time. Simple, but very handy. I suppose I could
also have it display V / I to show the load resistance in real-time. I think
the PSU approach is good for measuring very small resistances (when you need
to generate a lot of current to have a voltage drop large enough to measure
accurately.


At a local electronics store, there was a sale of multimeters for $5. I
bought a bunch and have velcroed some to my workbench. I set them for
voltage, current or resistance and leave them there. Good cheap way of
doing some quick and dirty measurements. Surprisingly accurate too. If I
smoke one, I just toss it. After all, it is a toss away world nowadays.

Al

--
There's never enough time to do it right the first time.......