Transitor/ESR tester dead

[SteveNielsen]

Re: Transitor/ESR tester dead

Ok. Will do. Finally ordered the rotary and programmer. I'll scrounge up stuff for the connections. Thanks.

[stj]

Re: Transitor/ESR tester dead

btw, put something over the display before you solder a header on, so you dont get flux on the panel!

[stj]

Re: Transitor/ESR tester dead

yes

attached:
the common programmer,
the standard header pinouts,

and pics of an adapter from ebay - that i dont own btw, just saved the pics.

[SteveNielsen]

Re: Transitor/ESR tester dead

STJ: Do you have wiring diag of the 10 - 6 pin adapter?

[vinceroger69]

Re: Transitor/ESR tester dead

http://www.ebay.co.uk/itm/DSO138-2-4...8AAOSw9r1WA5ep

[stj]

Re: Transitor/ESR tester dead

all over ebay.

btw, you could maybe add an SPI interfaced flash ADC chip.

[SteveNielsen]

Re: Transitor/ESR tester dead

Really? Got links? Yeah, that's all you could expect but an imperfect measurement gives more information than none at all.

[ben7]

Re: Transitor/ESR tester dead

Random thought - what if they could make this thing into a little o-scope? It'd need better graphics but that'd be fun

Oh, plenty of people have done that! Not very good performance, but hey, it can at least give you an idea as to what a signal looks like!


-Ben

[SteveNielsen]

Re: Transitor/ESR tester dead

Yep, you beat me to it.
It needs a faster ADC so it can capture the waveform, then calculate the ESR based on voltages and time (I think XD).
Of course, it could possibly do it with some external circuitry to trigger the ADC when it needs to measure a certain part of the waveform.

-Ben

Yeah, also something about it taking 1.5 clock cycles of the ADC after the charge is applied and in that time the charge is already decaying in the cap under test. I've been looking at the documentation a bit lately.

I don't know if ext ckt could speed up the process. I don't know enough about these chips but starting to learn a bit.

Random thought - what if they could make this thing into a little o-scope? It'd need better graphics but that'd be fun

[ben7]

Re: Transitor/ESR tester dead

The docs say say something about the ADC can't clock that fast. I think. Also states there a difference between using a sine wave and a square wave, the tester uses square wave.

Yep, you beat me to it.
It needs a faster ADC so it can capture the waveform, then calculate the ESR based on voltages and time (I think XD).
Of course, it could possibly do it with some external circuitry to trigger the ADC when it needs to measure a certain part of the waveform.

-Ben

[SteveNielsen]

Re: Transitor/ESR tester dead

The docs say say something about the ADC can't clock that fast. I think. Also states there a difference between using a sine wave and a square wave, the tester uses square wave.

[Per Hansson]

Re: Transitor/ESR tester dead

Wow, I'm jealous, that tester is so clever!
I thought you'd need to use much more circuitry to measure ESR ... but this thing measures ESR and more, with less!

Though I did spot that it says:
"You should not expect very good accuracy of measurement results, especially the ESR measurement
and the results of inductance measurement are not very exact."

I also see that it doesn't use a frequency of 100kHz to measure the ESR.

I've seen several of these testers that show they can be used as signal generators up to 2Mhz.
Does anyone have any insight to why they don't measure ESR at 100Khz then, sounds like it should be easy to do...?

[stj]

Re: Transitor/ESR tester dead

You can use for example 1% 0.1 Ohms resistor to see how close it is.
http://www.digikey.com/product-detai...10CT-ND/596475

resistance is accurate to atleast one - maybe 2 decimal points.

that's not the same as ESR though if the tester uses a different frequency from the factory making the datasheets - which is the case.

[stj]

Re: Transitor/ESR tester dead

i will do a test for everybody in the next couple of weeks, i know someone i can borrow a peak-atlas ESR-70 from.

[budm]

Re: Transitor/ESR tester dead

You can use for example 1% 0.1 Ohms resistor to see how close it is.
http://www.digikey.com/product-detai...10CT-ND/596475

[vinceroger69]

Re: Transitor/ESR tester dead

i wonder how accurate these ebay testers are the compared to a proper esr tester has anyone tried to find out i wonder.

[stj]

Re: Transitor/ESR tester dead

accuracy is improving,
there is a new calculation method being tested right now.
i'm not upgrading till they finish testing it though - i'm not their beta-tester!

also, you can change from an 8Mhz to 16Mhz crystal to improve test accuracy at the expense of battery life.

[SteveNielsen]

Re: Transitor/ESR tester dead

Yeah, it is not as accurate as a better ESR meter but it is close enough for my use. I really like mine.

[ben7]

Re: Transitor/ESR tester dead

Wow, I'm jealous, that tester is so clever!
I thought you'd need to use much more circuitry to measure ESR ... but this thing measures ESR and more, with less!

Though I did spot that it says:
"You should not expect very good accuracy of measurement results, especially the ESR measurement
and the results of inductance measurement are not very exact."

I also see that it doesn't use a frequency of 100kHz to measure the ESR.

i keep the covers from old tuners for that.

LOL, I do that too!
I keep some RF shields as well. They can be soldered to (not aluminum!), and I have some shears to cut the metal into whatever size/shape I need.

-Ben

[stj]

Re: Transitor/ESR tester dead

check the software repositry's - i bet avrdude is in it.