Hi All!
Long time listener, first time caller... So I'm studying electronics part-time, and part of our end of year course is a AD converter. So far the circuit is just a 5v power supply into a Schmitt Trigger, producing a clock signal for a 8-bit counter. All working normally.
8-bit counter feeds an R-2R ladder, this is here it gets hairy. I finished building the R-2R ladder and started testing resistances to ground. My 181A immediately started to confuse me. It shows me 2.5K Ohms between each input and ground.
However it's producing a smooth ramp. I check for shorts or anything odd, for a long, long time. Til I put my Fluke 18B+ from China on the case, and it gives me expected readings.
(Exact same pin as above but with the fluke meter...)
My aim now is to make sure this never happens again. I am bad enough at this without being lead astray by readings like these. So I need to figure out if the UT181A is faulty, or no good in these contexts. I would just love to kno hat's going on.
Thanks all! Your time and attention are hugely appreciated.
-James
Long time listener, first time caller... So I'm studying electronics part-time, and part of our end of year course is a AD converter. So far the circuit is just a 5v power supply into a Schmitt Trigger, producing a clock signal for a 8-bit counter. All working normally.
8-bit counter feeds an R-2R ladder, this is here it gets hairy. I finished building the R-2R ladder and started testing resistances to ground. My 181A immediately started to confuse me. It shows me 2.5K Ohms between each input and ground.
However it's producing a smooth ramp. I check for shorts or anything odd, for a long, long time. Til I put my Fluke 18B+ from China on the case, and it gives me expected readings.
(Exact same pin as above but with the fluke meter...)
My aim now is to make sure this never happens again. I am bad enough at this without being lead astray by readings like these. So I need to figure out if the UT181A is faulty, or no good in these contexts. I would just love to kno hat's going on.
Thanks all! Your time and attention are hugely appreciated.
-James