# Panel meter



## Bluedog (Dec 6, 2013)

I am building a control panel for my VFD with larger controls and I would like to add a panel meter to display the output. The output is 0 - 10VDC, 2mA max. Any recommendations for a panel meter that I can use to display the output as Hertz or RPM. I found one that I think will work, but costs more than my VFD did. 
Thanks


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## Tony Wells (Dec 6, 2013)

You could harvest the things you need from a cheap HF DMM. Basically, all meters are ammeters, and shunted and labeled to read as needed. If you need a frequency meter, HF even has a DMM with that funcion, IIRC. Otherwise, you will need to find one suited to your electronics that is calibrated in Hertz, or make a new meter face.


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## Bluedog (Dec 7, 2013)

I'm looking for a scalable display. For example I could set 0 V to correspond to 0 Hz and 10v to display 60 Hz with everything in between scaled accordingly. Not sure if that would be possible with parts from a DMM without some additional circuitry. If it could that would be great  
Thanks


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## Jeephead (Dec 7, 2013)

Check out Red Lion meters on the web. I use them a lot. They can be programmed to display what you want to correspond to volts or milliamps. Very accurate and easy to program.


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## lens42 (Dec 8, 2013)

Bluedog said:


> I am building a control panel for my VFD with larger controls and I would like to add a panel meter to display the output. The output is 0 - 10VDC, 2mA max. Any recommendations for a panel meter that I can use to display the output as Hertz or RPM. I found one that I think will work, but costs more than my VFD did.
> Thanks



Are you sure you really want Hz and not RPM? I stuck one of these:
http://www.ebay.com/itm/0-56-DIGITA...456?pt=LH_DefaultDomain_0&hash=item5af8b92f38

into my VFD box. Works a treat with a little opto reflective speed sensor on my lathe.


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## Bluedog (Dec 8, 2013)

Jeephead,
I looked at Red Lion, and the ones I saw were about $200.  Are there cheaper ones that I overlooked?  Which one did you use?  Did you buy it direct or from a distributor?  

lens42,
I just used Hz as an example.  With the scalable panel meters, I could also scale the output to correspond to RPM, but the problem with that is that my Wells Index mill is belt drive just like a Bridgeport J head, so if I move the belts I would have to re scale the meter.  I might find that I use a common belt setting most of the time and scale the meter to correspond with those speeds.  With the meter you posted, that would not be a problem if I could find a good spot to mount the head that reads the tape.  The spindle would not be a good spot, but I might mount it on the drawbar.

Thanks


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## lens42 (Dec 8, 2013)

I took off my spindle brake disc and painted black stripes on the outer edge, then mounted the optical sensor in the step pulley head. It all was very easy to get at on my BP clone.


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## SEK_22Hornet (Dec 8, 2013)

You might also look at the Tachulator mentioned in this thread - http://www.hobby-machinist.com/showthread.php/18858-Need-help-with-a-VFD-for-my-mill . Looks like a very neat gadjet and I believe the guy said it was under $100. 

Dan

Edit - added this link to Tachulator - http://tachulator.com/tachoptions.htm


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