DVM / Counter

Question:
I have connected supply voltage and reset to my EA 6110-13EA counter and am trying to count pulses with my function generator. But the display only shows some numbers. The reset does not work either. Should I send you the part?

Answer:
I don't think that's necessary. Put pin 9 (store) on VSS (pin 2), then the counter will work. Due to an internal pull-up resistor, the display memory is always activated; It counts in the background, but you just don't see it. The reset also only runs in the background.

Question:
Our problem: a current measurement (up to 4A) with the display module EA 4044. With a shunt resistor, a 10mOhm resistor would be necessary according to our calculations. That is not feasible (conductor resistance, solder point resistance), we would be very binding if you could present us with a proposed solution.

Thank you Mr. P.

Answer:
Your calculation is correct. The current to be measured must flow through a 10 mOhm shunt. Appropriate cables and clamps are required for this so that the voltage drop (and heating) does not become greater than absolutely necessary.

It is best to insert the shunt into an existing line. In order to measure this voltage drop, a simple wire is enough to the inputs INHI and INLO of the DVM. This line can be so simple because almost no current flows here (nA), because the EA 4044 voltmeter has a very, very high resistance.

Question:
Inquiry: I need a voltmeter in modular design to measure 150-250 V AC. Execution in LED or LCD is irrelevant. If you offer something like that, I would be interested in product information.

Answer:
In principle, we only offer voltmeters for measuring DC voltage. All DVMs have a sensitivity of ± 200mV and are very high-frequency.

Together with an additional RMS module (EA 9410-RMS), it can also be used to carry out a true RMS measurement. The mentioned rms value addition is best for the module series EA 4110-xxx (data sheet, pdf, 835kB).

There is also space for divider resistors to adapt the measuring voltage.

If a real RMS measurement is not required (constant waveform and frequency, no high accuracy required), it is often sufficient to simply connect a bridge rectifier and a buffer capacitor as an AC-DC converter in front of the voltmeter.