An inductor with infinite inductance is a resistor.
The k-firmware goes down to 30pF and the m-firmware down to 5pF. With the current hardware design and the implied measurement methods low value measurements aren't really feasable. The oscillator method (frequency counter) or the AC generator method (U and I) are suited much better for that purpose. That's something for a Tester+ ;-)
For steady state DC, any inductor - infinitesimal or infinite - would (as I read it) behave as a zero effective impedance - a short.
* My board is marked as v 2.4 and is stock / as delivered. It is running the 1.05k software.
* Transistortester resistance readings are within about 1% from 100 ohms - 1 Mohm. Low values have higher error. It doesn't look like it reads < .7 Ohms.
I have revision 2.2 of that board and comes with the 8MHz crystal. Too bad they removed it from newer revisions. Mine is bricked after I tried to update the firmware. I tried using the MiniPro TL866A and the USBAsp but fails. I don't know if the processor is cooked or something with the fuses. I have some Atmega328P-AU to replace the Atmega168. My USBAsp has the warning: cannot set sck period. please check for usbasp firmware update problem so I'm trying to breadboard another USBAsp to program the original one. I feel that for every problem I fix I get two new ones
* My board is marked as v 2.4 and is stock / as delivered. It is running the 1.05k software.
* Transistortester resistance readings are within about 1% from 100 ohms - 1 Mohm. Low values have higher error. It doesn't look like it reads < .7 Ohms.
Please update to 1.10k (1.05k is about 15 months old). That version measures low value resistors down to 0.01 Ohms.
Is there a place to submit features request? I have a french made transistor tester, but the software has not been updated. They do have a function to test opto-coupler. On powerup, it shall detect if the opto-adapter is attached and so shall "mode" opto coupler testing. Giving the CTR value accordingly. Also is it possile to test MOSFET or IGBT driver chip, and those that are opto-isolated driver?
I put my AVR tester into a metal housing and I am getting wrong measured values of capacitors. What to do with that? Maybe a plastic housing would be better?
Just for values in the pF range or also for µF? How much are the values off?
Have you connected the metal case to the tester's ground or is the tester completely isolated?
Yes, the metal case is connected to the tester's ground.
Well, this is strange. The fault appears only when simple non-switched PSU is used. When I use an industrial switched PSU, the problem never appears.
as mentioned the ones with graphic lcd will never be up to date with latest firmware. and dont really show more info. i also have a feeling it will be more than $11 before bidding ends. there are many out there easily impressed by bling.
Moving away from the $1 range, I have a couple of MCP3424s (4 ch, 18bit ADCs + Vref) sitting here looking for a home. Do you think there would there be any benefit swapping one in place of the internal ADCs and changing the code to accommodate of course
Moving away from the $1 range, I have a couple of MCP3424s (4 ch, 18bit ADCs + Vref) sitting here looking for a home. Do you think there would there be any benefit swapping one in place of the internal ADCs and changing the code to accommodate of course
For some measurements an 18 bit resolution would be nice but the MCP3424 has some issues. It's really slow at 18 bits and can only use the internal 2.048V voltage reference. Therefore it would be only usable for high resolution measurments if the voltage is below 2V and if there are no timing constraints. The tester uses also the ATmega's analog comparator feature (taking the ADC pins as inputs for the comparator) and the ESR measurement performs exact timing of the internal ADC's S&H. You could add the external ADC in parallel and use it for more precise low voltage measurements, e.g. for resistors.
Yes, the metal case is connected to the tester's ground.
Well, this is strange. The fault appears only when simple non-switched PSU is used. When I use an industrial switched PSU, the problem never appears.
Could you please remove the connection between the metal case and ground and check again.