So I have digital calipers on my Taig lathe to measure .00015" or .01mm and they take an LR44 1.5v battery.
The battery drains even when off so I found a 1.5vDC wall adapter and wired it up. Weirdly, under this very light current (amp) load it was giving almost 3v.
So I put a resistor on the negative wire. I tried a few and either got: nothing; all the numbers showing 888888; or almost zero but when I hit the "zero" button it would jump to .0005 or 6 or 7. I tried a bunch of resistors until the 51k Ohm resistor let me hit the zero button and the display stayed at .0000" or 00.00mm.
Since the 1.5v setting on the wall transformer was putting out 3.3v that means I can replace it with a less odd USB cable (although many are 5v). I'd probably have to change the resistor for a slighly higher value.
I works and no batteries needed.
2.8v or 3.3v we don't care, meows!
