Analog ESR meter with linear scale?

[dardosordi]

Hi,

Im looking for a schematic or some pointers on how to build an analog ESR meter with linear scale.

I've built one with log scale in the past, it served me well, but the enclosure was pretty bad and it ended up falling apart. So I bought a non-working Power Instruments B-891 Tachometer to use for enclosure, and it has a really nice analog display with linear scales. I was wondering if its possible to build an analog ESR meter with linear scales, so I don't have to re-do the scale markings.

It comes with dual scale: 0-10/0-3 and has a 4 pole-5 position rotary switch that I could use to implement different ranges, but I first need to get a circuit with a linear response. It also has a nice calibration pot wit a shaft made for a screwdriver.

Any help is appreciated.

Im attaching pictures of the tachometer, the batteries had leaked and it was missing the sensor, so it didn't seem worth repairing.

[Kalvin]

Like this?

https://www.eeweb.com/blog/extreme_circuits/esr-low-resistance-test-meter

[dardosordi]

Like this?

https://www.eeweb.com/blog/extreme_circuits/esr-low-resistance-test-meter

That actually might work, thanks!

[dardosordi]

Kalvin,

you made me realize the problem with my search was that I was looking for "analog display" and "linear scale", but the way the scales on this meter are any of the ESR adapters that are designed to work on DMM will work. 

Thank you very much, I'll go with this one https://www.eevblog.com/forum/projects/esr-meter-adapter-design-and-construction/ and post the results here.

[hugo]

An analog one by the same designer, Jay_Diddy_B here :

https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/