An answer from the other forum:
The apparent problem is that a DMM that functions correctly when powered by 3 volts of batteries does not function correctly when powered from a 3 volt regulator supplied by a 5 volt switching power supply.
- You understood the problem perfectly ! It is exactly what I did.
It does function, but with an additional error that was not there while powered normally from 3V batteries.
The error is like this:
-1- while NOT measuring anything, when the probes are on the table, and importantly, my arms or hands are very close to them or touching them, the display is picking random frequency, around 300Hz. Why I say important, because when I lift away my arms or hands from a certain area around the DMM, it starting to behave normal, without any random fv reading.
-2- I only tested measuring Resistors. Its the only thing it is VERY good for. In my experience and I love it for that. It is searching automajically for the x R value, no need to switch the knob to a certain range like the old DMM. Some of you probably already know already this function. Anyway, AFTER measuring a 10k, it was continuously search for other R values but not stopping from the search as before. It is randomly jumping from M to null to k.
Notice how in the picture attached, I keep my hands in air, but it is displayed a value there. That value actually is switching randomly at an interval of 1/s.
These are the 2 major errors I observed. Maybe there are others. I didnt do all the DMM operations. I did measure voltage one time and AFTER measuring, it is jumping in values as with the R, but for the V values.
My opinion is it's autosearch function mest up somehow.
-3- All the measurements are FINE, are ok, with this error that happens AFTER the measuring. So the values measured are OK. It is doing its thing as a DMM. No problem there. But After, instead of stopping from its usual automatic search, it is jumping around.
-4- If im putting back the batteries, everything gets back to normal as before !!! No errors of any kind. This tells me loud and clear it is the power supply Hack that I made.
--5--Thats why I wanted you to watch my movie because I did ALL this explanations here in writing, there live in the video and more. Including changing the batteries. It is a very good and efficient way of explaining a problem through a video. It's like showing you the problem instead of explaining it in writing. It is how I see it. But I also understand your point of view as well, the music is too much perhaps, it is a german military march from 1945 btw, my beautiful carphatian voice, accent or speed might not be on the same resonance with some ears. heh. Or movies in general excepting me personally. Hmm....I make the best ones on the whole world, haha.
