DSE Q2220 3.5 digit LCD display HELP please?

Question

One of the applications circuits on the paperwork that comes with this device allows the measurement of the voltage of the supply powering it. I've built it.

On the BOARD of the device itself are a number of pads, tracks and connections that LOOK to me as if they are designed to do this job with appropriate SMD components. I can't quite figure out whether this is the case.

Has anyone used the back of the board to set up the negative power supply generator as shown on the paperwork? Any advice/info?

Thanks

JimW52 · Accepted Answer

Although I haven't tried it, I have traced the tracks and it is indeed the same as the schematic shown. Go ahead and build it, all should be fine.Jim

Colin Earl · Answer

Yes, the PCB allows adding the -ve supply generator components. From memory there are also solder pads which need bridging and/or some PCB links cut to join the measurement reference to the 0V supply terminal and shift the module supply to the output of the added generator.

I remember also thinking a bit later that you could get the module to measure its own supply just by using a 3-resistor voltage divider, with the resistors chosen so that the voltage at the bottom of the middle resistor was above whatever it needs to be, and the voltage across the middle resistor was 1/10th the supply. Then set the range / decimal point accordingly and just measure the voltage across the middle resistor.

DSE Q2220 3.5 digit LCD display HELP please?

Join the Discussion

Didn't find your answer?