Hi,
I sent for a generic ebay 5135 type digital panel hall switched tachometer. What I actually received instead was the frequency meter version of this same panel meter. I hadn't installed it and realized the problem by the time the return date was long passed. I was wondering if these meters are convertible internally. I did see one similar digital tach/frequency meter that has a circuit board switch specifically for doing that.

Mine does not have a switch, but I was wondering if there's a jumper, or clipable component lead somewhere, or a component to be added that would allow it to be used as a tachometer. I just have a strong feeling that these boards are multi-use, but maybe I'm wrong. No great loss, but I'd hate to just shelve this rather than put it on my lathe.

I do know I can convert by multiplying by 60 mentally, but that's no fun! Or as much fun as fixing this, if it can be.

If anybody already has experience with converting these, that would be great. If you need a photo of the populated circuit board I can get that posted tomorrow morning.

Thanks for any help!

Best,
Steve

 

Could you use it with a 60 PPR encoder?

 

Yes, Strantor, thanks kindly for replying. I imagine so. But the lathe has already been set up with a hall sensor in the headstock casting and magnet embedded in the spindle drive wheel. I'd really like to use what I have, if it is just a matter of doing a minor circuit alteration to the meter itself.

 

Searching the net I just found some helpful additional information in a description of the circuit. This is for the tachometer version, not the frequency meter version, but perhaps someone here will find it useful:
https://www.electroschematics.com/digital-rpm-counter-intro/

 

I just took a photo of my frequency meter, and a similar tachometer side by side. The tachometer came from my drill press. The tach is on the left, the frequency meter on the right. Hope that helps.

 

They certainly look almost identical. I can't read all the resistor values on the frequency board from the glare to compare but two resistors on the tach board circled in red are different.

 

I suspect that the hardware is identical but the difference will be in the firmware.
Even if you have the tachometer version it is probable that the firmware is read protected so you would not be able to copy the code to the frequency meter version.

Les.