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LCR & Semiconductor Tester

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peterscott
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This thread on the other place is interesting reading and induced me to buy one too:

http://www.vintage-radio.net/forum/show ... p?t=104177

Peter

www.nostalgiatech.co.uk

 
Posted : 06/07/2014 9:33 am
peterscott
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Likewise, I don't really need it but the direct ESR measurement had appeal.

I opted for this one:

http://www.banggood.com/Transistor-Test ... 19181.html

Peter

www.nostalgiatech.co.uk

 
Posted : 06/07/2014 12:09 pm
Niall
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I got one of the bareboard ones but it doesn't seem to measure ESR. I tried a variety of caps and adding series resistance but there is no ESR displayed.

 
Posted : 06/07/2014 12:16 pm
peterscott
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Hi Niall,

I will probably need to wait a few weeks before I receive mine but reading the other thread it seems that these devices react differently to different durations of pressing the start button. Try holding it down a little longer.
There was also mention of a faulty button.

Peter

www.nostalgiatech.co.uk

 
Posted : 06/07/2014 12:24 pm
Lloyd
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I've now got 2 of these little testers, not had any problems so far!

The newest one has a really good display, it even draws you a little diagram of the component! I found it most useful for a drawer full of unmarked plastic cased transistors I got, sorted out the dud's from the good, told me what connection was what and if it was NPN or PNP. Also good for weeding out bad caps that look OK in PSU's and computer motherboards.

Both of mine show ESR, you have to pick the best ones from the listings if you want the ESR measurement, or better display, some of them are lacking in these departments!

If anyone wants, I can find the links to both of mine.

Now just need to make some nice cases for them..!

Regards,
Lloyd.

 
Posted : 06/07/2014 12:38 pm
Niall
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Mine looks like the top one in the picture.

I just went to try it again and it appears to have died. Oh well, it was really cheap, might buy one of the better ones now.

 
Posted : 06/07/2014 3:08 pm
peterscott
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Likewise, I don't really need it but the direct ESR measurement had appeal.

I opted for this one:

http://www.banggood.com/Transistor-Test ... 19181.html

Peter

Well, it has arrived safely from Guangzhou with no additional charges and seems to work quite well. It doesn't recognise capacitors lower than about 27pF and it doesn't measure inductance below 0.03mH. Smaller inductors are seen as resistors. Semiconductors look quite credible. Must check what collector current is used for beta test.

I don't have a battery for it so I plugged a wall wart that claims a 9 volt output. The tester checks the "battery voltage" before doing anything and doesn't complain that it sees 13 volts in my case.

That said I did have one or two silly results when checking capacitors. Instead of measuring the component clipped on, it told me that a very much larger capacitor was connected twixt one of the terminals I used and the one that was left open circuit! Perhaps the acceptable 13 volts is not really acceptable.

Construction looks quite good. This one uses ATmeag328 and has an 8MHz crystal.

Peter

www.nostalgiatech.co.uk

 
Posted : 15/07/2014 7:11 pm
jimmc101
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If anyone is still tempted by these, I've just found this kit for £7.92, at that price I couldn't resist.
http://www.banggood.com/DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-Resistor-NPN-PNP-p-929603.html

Jim

 
Posted : 01/11/2014 4:46 pm
Dr Wobble
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They look good Jim. Ta for the heads up.

Andy.

Curiously curious

 
Posted : 02/11/2014 12:01 pm
jimmc101
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I've built the kit (see above) and it works well, board size is 80x80x23 (inc solder joints under board). It was supplied with an ATmega328 running v1.05k software.

Minor points...
There are tracks under the (metal can) Crystal, the solder resist should stop shorts, but I used mylar tape to be sure.
There is not much clearance between the top of the 10uF caps and the bottom of the display board, I angled the one nearest the crystal towards the processor to avoid a chip resistor on the display.
The 'ON' LED is hidden by the display, this is not really a problem as the display backlight does the job.

The website with the original information is http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.mikrocontroller.net%2Farticles%2FAVR_Transistortester
To get the relevant documentation, download the 'GNU tarball' http://www.mikrocontroller.net/svnbrowser/transistortester/?view=tar (! BIG >40MB)
Open with 7-Zip or similar and navigate to transistortesterDokutagsoldenglishttester_eng105k.pdf

There is a self-test /auto-calibrate routine initiated by shorting out all three test terminals (>100n capacitor required to complete tests) the software version is given at the end of the routine.

Jim

 
Posted : 16/11/2014 7:37 pm
jimmc101
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The kit is now available with matching case http://www.banggood.com/86-Plastic-Shell-DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-p-956240.html £9.17!

Jim

 
Posted : 21/11/2014 8:12 pm
ken
 ken
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Have just sent for one of the above. Santa is bringing it so it will be a little while till it gets built.

Regards,

Ken.

 
Posted : 01/12/2014 4:09 pm
Anonymous
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I've bought one of these and it works generally well except that it doesn't seem to recognise point contact diodes and insists that the battery is 20V!

 
Posted : 20/12/2014 6:41 pm
jimmc101
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I've bought one of these and it works generally well except that it doesn't seem to recognise point contact diodes and insists that the battery is 20V!

The 20v battery reading suggests a problem with the R11 / R12 divider (10k / 3k3) these resistors are situated along the edge of the board by pin 1 of the processor.
Check that values are correct and that R12 (3k3) is not dry jointed.

I believe that the supplied version of the firmware (1.05k) has problems with Germanium devices, I've updated mine to the current version (1.11k) and this seems to work.
(I've tried it with these diodes and 1N34s)

(The croc clip on the left is an earth wire to cut down stray voltages, I'm using a switch-mode PSU)

Jim

ps Anyone know what diode this is... DO-7 case with (from cathode end) Green & white (or grey) bands, IN58?

 
Posted : 21/12/2014 9:20 pm
ken
 ken
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Hello All

Have only recently got my kit. It was supposed to take up to 25 working days but took longer although I am not factoring in the holiday period. It was relatively easy to build the kit. I bought the one with the case at £9.17. I have seen the case listed separately at £1.61. I noticed that the prices seem to vary from day to day. I guess this is due to exchange rates. The site says the box needs "trepanning" It certainly needs a bit of work and this took me longer than building the kit. The three small buttons are all dummies. They are hat shaped so easily glued to the case. The one nearest the middle fouls the battery and the rim had to be sanded down. The large button is "on". A hole has to be drilled in the case for this and the external power supply. I also had to drill three holes and extend the to a slot to allow components under test to be plugged in. I have made some short (about 300mm) leads. I presume the will not affect capacitance readings other than those of very low value. I also wondered about how the ESR values of electrolytics would be affected. I've attached some pictures.

jimmc101

Can you please tell me
(1) How you found out what firmware you had.
(2) Where you found the update.
(3) How you updated the firmware.

Regards,

Ken.

 
Posted : 18/01/2015 8:40 pm
jimmc101
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In answer the questions

1. Firmware - this is shown at the end of the test sequence. To run the test sequence short all three terminals together and press the test button. To complete the sequence you will need a capacitor of 100n or more (non electrolytic).

2. Update - details of the original project, including documentation, are here http://www.mikrocontroller.net/svnbrowser/transistortester/ for the latest firmware you need to extract 'TransistorTester.hex' from http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/?view=tar (I use 7-zip)

3. Programming - I used a USBasp £1.60!!! ( http://www.ebay.co.uk/itm/281365348532? ... BIDX%3AIT# or similar).
I actually bought 2 and used each to program the other with the latest firmware.
Drivers were installed using 'Zadig', software was 'AVRDUDE' with 'AVRDUDESS' as a front end (GUI)
I built a simple jig with a 28pin ZIF socket, 4MHz crystal (&caps) and decoupling to program the m328 so that I could try a spare processor first, an alternative would be to add a programming interface to the tester.

Jim

 
Posted : 18/01/2015 9:48 pm
ken
 ken
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Hi Jim

Thanks for the information. I'll check what firmware I've got to see if I need to update it. I do not have the battery reading problem. Mine originally read 9.2V and now reads 9.0V. I have not tried testing a germanium diode. I do have some but I'll have to find them. I have found that when testing the same 1000microF electrolytic A number of times I get slightly different ear readings. I'm not sure if this is to expected or not. I've no experience of programming these chips but I might have a try. May look for another m328 to try it.

Thanks again,

Ken.

 
Posted : 18/01/2015 10:30 pm
peterscott
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(I've tried it with these diodes and 1N34s)

(The croc clip on the left is an earth wire to cut down stray voltages, I'm using a switch-mode PSU)

Jim

ps Anyone know what diode this is... DO-7 case with (from cathode end) Green & white (or grey) bands, IN58?

If it has a Vf of 0.4 volts it sounds like a Schottky diode.

Peter

www.nostalgiatech.co.uk

 
Posted : 19/01/2015 12:04 am
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