Author Topic: $20 LCR ESR Transistor checker project  (Read 1471283 times)

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Offline Dark Prognosis

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Re: $20 LCR ESR Transistor checker project
« Reply #150 on: October 01, 2013, 01:20:31 pm »
Yes, you will need an AVR ISP programmer to upload the new firmware, which is a *.HEX file.

BUT, things are a little more complicated than that because the latest TransistorTester revisions have extended functionality and require the mega328 AVR microcontroller, which has 32 kB of FLASH memory. Most (if not all) of the chinese TransistorTester knock-offs have the cheaper and smaller mega168 that has 16 kB of FLASH memory only or, even worse, the even cheaper mega88 with 8 kB of memory or the older mega8. The latest firmware will only fit in 32 kB memory, if you want it to have full functionality; or else, you will have to recompile the project with some functions disabled (read the project files, I do not remember specific details) in order for the firmware to fit in FLASH memory sizes of less than 32 kB.

So, with the ISP programmer, you will firstly need to check which microcontroller is on board (since most of these knock-offs usually have their chip identification marks erased). If the programmer identifies the microcontroller to be a mega328, you will just have to load it with the latest firmware and you are done. If the chip is identified as a mega168/mega88/mega8, you will also need to change it with a mega328.


-George
The sellers are just too stupid to help and I know I don't do SMT so now I just need to find someone with some self respect and decency and BRAINS who tell you what is on it.
 

Offline A Hellene

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Re: $20 LCR ESR Transistor checker project
« Reply #151 on: October 01, 2013, 03:15:35 pm »
Well, you can let the sellers remain ignorant or non-helping, and use your eyes, knowledge and good judgment instead!

After a brief search I found several e-bay Testers with a PDIP chip on board, which is most easy to be changed if it is not an m328.

What to look for in the pictures of the Testers that you will find:
- There should be a crystal on board, for the time-depended measurements accuracy.
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.
- This is not critical but there should be a golden-plated socket for the chip, for better contact with the chip pins. If there is a cheap socket you can either leave it as is or change it with a better one.
- There should be an ISP header or socket. If there is not, an ISP header can easily be fitted in an unpopulated PCB area with a hot-glue gun, and be connected through cables directly soldered to the four ISP lines of the chip socket pins and to the GND and Vcc lines.
- Make sure that the seller will ship to you *exactly* what you have ordered.

This is not a rule but, a better looking and more pleasing to the eyes PCB layout and construction is usually made by a better designer.


-George
« Last Edit: October 01, 2013, 03:18:09 pm by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline Dark Prognosis

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Re: $20 LCR ESR Transistor checker project
« Reply #152 on: October 01, 2013, 03:40:48 pm »
Well, you can let the sellers remain ignorant or non-helping, and use your eyes, knowledge and good judgment instead!

After a brief search I found several e-bay Testers with a PDIP chip on board, which is most easy to be changed if it is not an m328.

What to look for in the pictures of the Testers that you will find:
- There should be a crystal on board, for the time-depended measurements accuracy.
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.
- This is not critical but there should be a golden-plated socket for the chip, for better contact with the chip pins. If there is a cheap socket you can either leave it as is or change it with a better one.
- There should be an ISP header or socket. If there is not, an ISP header can easily be fitted in an unpopulated PCB area with a hot-glue gun, and be connected through cables directly soldered to the four ISP lines of the chip socket pins and to the GND and Vcc lines.
- Make sure that the seller will ship to you *exactly* what you have ordered.

This is not a rule but, a better looking and more pleasing to the eyes PCB layout and construction is usually made by a better designer.


-George
Good things to look for but I am finding most of these sales are from the same handful of sellers that are selling a ton of them all at once so it looks like there is more than there really is.  What I do is not even look at the seller's name and scan down to the pics and descriptions and within 10 secs I can tell it is the same as a previous one I looked at.

You know I am beginning to wonder how many Chinese sellers Ebay really has as this is not the first product that seems like a ton of sellers with all sorts of different prices and even with some make offers (they never work for me) but they are all from the same handful of sellers.
 

Offline Shock

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Re: $20 LCR ESR Transistor checker project
« Reply #153 on: October 01, 2013, 04:56:30 pm »
1. Looks like one of the nicer ones.  Be interesting to see that board revision number.
http://www.ebay.com/itm/151124228042

2. Similar but blue screen
http://www.ebay.com/itm/181225081033

3. Zif socketed one
http://www.ebay.com/itm/231056057317

4. Looks like a later board revision here pity no gutshot
http://www.ebay.com/itm/121184647718

5. Battery powered, USB
http://www.ebay.com/itm/390589763450
« Last Edit: October 26, 2013, 08:22:58 pm by Shock »
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 87V, 117, 27/FM
Oscilloscopes: Rigol DS1054Z, Phillips PM3065
 

Offline Dark Prognosis

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Re: $20 LCR ESR Transistor checker project
« Reply #154 on: October 01, 2013, 05:06:02 pm »
Notice all of those green boards are from the same people and are V2.2/2.3 but that red board is a bit intriguing though one of them (I forgot which one) had what I thought very lousy results as they showed what the value was and what it read.  Close but 10% close I think it was which is pretty bad (33uH read .03mH).
 

Offline Dark Prognosis

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Re: $20 LCR ESR Transistor checker project
« Reply #155 on: October 01, 2013, 05:52:03 pm »
Or a 5*2 pin 90° Degree header.


-George
I did a little more digging via the spec sheet as I was noticing something odd and I was correct.  The height is 9.1mm of a standard 10 (5x2) IDC connector and the height of the same connector at a 90 degree angle is 9.0mm.  So, the bloody thing is as deep as it is tall. :/
 

Offline A Hellene

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Re: $20 LCR ESR Transistor checker project
« Reply #156 on: October 01, 2013, 06:31:35 pm »
Looks like one of the nicer ones.
I could not recommend something for which I do not have the precise specifications. This is what I can see and deduce from the pictures, with the devices numbered in the order they are presented:

- Numbers 3 and 4 seem to be more robust because they have their LCD PCB secured on the mainboard with bolts and spacers.
- Numbers 1, 2, 5 and probably 4 come with unknown chip (probably an m168) in TQFP package, and with ISP socket.
- Numbers 1 and 5 do not seem to have a crystal time-base, which is required for the time-depended measurements accuracy.
- Number 5 with the LiPo battery has an on-board DC-DC converter, that might increase electrical noise.
- Number 4 is called 'M8 transistor tester' (because of the mega8 it possibly has on board?) Is the chip in PDIP or in TQFP package? Does it have a crystal time-base?
- Number 3 has a mega328 in PDIP socketed on board and runs a firmware that seems to be more recent than the other ones. The m328 can be removed from the socket and be updated with an AVR ISP and a breadboard.

[...] So, the bloody thing is as deep as it is tall.
So, trimming the pins and insulating the LCD PCB might work.
But, what the reprogramming is good for if the chip is not an m328?

EDIT: By the way, I should warn you to be careful with the AVR Fuses because a wrong setting can brick the chip and its revival can be from difficult (by the injection of an external clock) to painfull (by desoldering and HVPP with a special HV programmer, like the ATAVRDRAGON).


-George
« Last Edit: October 01, 2013, 06:53:07 pm by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline darrylp

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Re: $20 LCR ESR Transistor checker project
« Reply #157 on: October 01, 2013, 07:20:35 pm »
Here is my socket, no problems with clearance.






--
 Darryl

 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #158 on: October 01, 2013, 10:35:29 pm »
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.

The 680 and 470k Ohms resistors for the test pins should have a 0.1% tolerance. Or you could select matched ones and update the default values in config.h.
 

Offline A Hellene

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Re: $20 LCR ESR Transistor checker project
« Reply #159 on: October 01, 2013, 10:58:38 pm »
We are in total agreement, dear Markus.

But, I was talking about Through-Hole resistors. It is almost next to impossible to find through-hole resistors of a better than 1.0% tolerance in the retail market (at least, over here, in Greece). On the other hand, SMT resistor chips of 0.1% (or 0.05% or even 0.01%) tolerance is not only feasible to find but it is also accessible and obtainable at a reasonable price (in Digi-Key/Mouser/etc.).


-George
« Last Edit: October 01, 2013, 11:04:22 pm by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #160 on: October 01, 2013, 11:52:27 pm »
But, I was talking about Through-Hole resistors. It is almost next to impossible to find through-hole resistors of a better than 1.0% tolerance in the retail market (at least, over here, in Greece). On the other hand, SMT resistor chips of 0.1% (or 0.05% or even 0.01%) tolerance is not only feasible to find but it is also accessible and obtainable at a reasonable price (in Digi-Key/Mouser/etc.).

Reichelt sells 0.1% through-hole resistors (Yageo) for € 0.16 each in case if someone has problems with finding any and lives in the EU. Otherwise you could create through-hole resistors by adding some wire to the SMT resistors :-)
 

Offline A Hellene

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Re: $20 LCR ESR Transistor checker project
« Reply #161 on: October 02, 2013, 12:33:03 am »
Reichelt: 680 Ohm/470 kOhm! This is interesting, thank you!
I did not know that, neither did I do any search in the wider EU market for such components, since I have learned how much it hurts to be purchasing very low quantities from the known component warehouses. Now I know better, thanks to you!

Well, what I did with what I was able to find locally, was to get 10 x 1% resistors of each (critical) value and to use the three of each value that I could match with the ohmmeter as close as possible to each other, updating at the same time the project configuration file resistor values with the actually measured ones. The result was not bad, giving me almost 0.1% match between the measurement readings of the same component that I tested using all the three combinations of the test-point pairs (TP1 to TP2, TP2 to TP3 and TP3 to TP1).


-George
« Last Edit: October 02, 2013, 12:34:38 am by A Hellene »
Hi! This is George; and I am three and a half years old!
(This was one of my latest realisations, now in my early fifties!...)
 

Offline TonyGreene

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Re: $20 LCR ESR Transistor checker project
« Reply #162 on: October 07, 2013, 12:37:22 pm »
I bought a couple of these units off of Ebay - SamLove from China.  These units use the ATMEGA328P-PU in the long DIP form.  They do not have the 2.5V voltage reference on Pin 27, but they do have the 8 Mhz crystal and the bypass caps.

I did a test, right out of the box, and here is the results, with no calibration;

47pF 5% Mica         55pF            52pF
150pF 5% Mica         162pF            161pF
300pF 10% Mica         323pF            322pF
470pF 10% Mica         470pF            459pF
560pF 5% Mica         574pF            571pF
3000pf 2% Mica         3062pF         3040pF
4300pF 1% Mica         4392pF         4369pF
8200pf 1% Mica         8394pF         8347pF
11000pf 5% Mica         10.67nF         10.62nF
17000pF 2% Mica         17.27nF         17.17nF
.00604uF 3%            6060pF         6025pF
.00301uF 3%            3151pF         3136pF
.0243uF 3%            25.09nF         24.62nF
.0478uF 3%            48.31nF         47.44nF
.075uF 1%            75.98nF         75.5nF
.0768uF 1%            78.14nF         77.70nF
.183uF 2%            185.1nF 1.6o         182.2nF 1.2o
1.0uF 10%            1112nF .42o         1106nF .42o
1uF Tant            1051nF 4.3o .5%      1038nF 5.7o .6%
2uF Mylar            2216nF .25o         2203nF .24o
3uF Mylar            3143nF .22o         3124nF .21o
4uF Mylar            4151nF .22o         4127nF .21o
10uF Tant            diode 3.57V 11.5uF      diode 3.92V 11.2uF
1uF Mil Glass            990.1nF .91o .1%      979.3nF .89o .1%
100uF Electro            100.2uF .52o .4%      97.43uF .51o .5%
234uf 10% NP Aluminum Electro   230.9uF .23ohm 1.0%   223.7uF .21o 1.2%
470uF Electro            544.ouF .24o .5%      529.8uF .34o .7%
2000uF Electro         2154uF .2o .6%      2096uF .18o .6%
3300uF            3318uF .19o 1.5%      3249uF .21o 1.3%
8000uF Electro         8999uF .22o .6%      8779uF .20o .6%
10,000uF Electro         11.67mF .20o 1.6%      11.38mF .16o 1.6%

10uH               .5o .01mH         .4o .01mH
100uH               1.5o   .09mH         1.6o .09mH
2.5mH               20.0o   2.64mH      19.7o 2.61mH
30mH               3.1o 29.8mH         3.2o 30.1mH
44mH               55.7o 40.8mH         56.7o 40.5mH
50mH               46.7o 50.8mH         47.5o 50.8mH
120mH            158.8o 122mH      159.6o 123mH
250mH            32.8o 248mH         33.5o 247mH
720mH            44.3o 703mH         45.0o 701mH
2.3H               62.3o 7.46H         63.5o 7.75H

zero ohm .1% decade         .28o            .27o
.5 ohm decade         .66o            .79o
1 ohm decade            1.28o            1.31o
5 ohm decade            5.34o            5.51o
10 ohm decade         10.5o            10.7o
50 ohm decade         50.8o            51.7o
100 ohm decade         101.2o            103.1o
500 ohm decade         498.8o            499.2o
1K decade            1003o            1003o
5K decade            4957o            4888o
10K decade            9955o            9786o
40K decade            40.57K         41.30K

10K .1$ MF            9786o            9962o
162K .1% MF            161.8K         162.0K
300K .1% MF            300.2K         300.3K
499K .1% MF            499.2K         499.6K

100 ohm .05% WW         101.1o            102.9o
1K .01% WW            1003o            1003o
10K .01% WW         9955o            9788o
100K .01% WW         101.2K         103.0K
1M .01% WW            1002K            1002K
9M 1% WW            9215K            9032K

RS2761067 SCR 200V 6A      NPN transistor....
2N3440            B99 595mV         B100 663mV
2N3906            B190 674mV         B186 748mV
2N5415            B72 660mV         B70 659mV
IFR820 FET            N E MOS C958pf V+3.31V   c941pF 3.33V
MPF102 FET            N JFET 2.7mA gs 1.87   2.7mA gs1.89

1N4146            709mV 10pF         787mV 9pF
1N5400            604mV 84pF         642mV 82pF
1N6263            573mV 8pF         586mV 8pF
MBR10H100CT         363mV 363mV      369mV 369mV



 

Offline TonyGreene

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Re: $20 LCR ESR Transistor checker project
« Reply #163 on: October 07, 2013, 12:38:13 pm »
Another picture close up

These units are nice for us older folks, who can't see like we use to, it will make sure the parts are in the right ballpark before stuffing our boards.

I do plan to add the 2.5 volt reference and put the units in a case.

I think, but not sure that the software in these units are either 1.07 or 1.08.  The seller never could answer the question.  I would be nice to put the version in the bootup screen.

(added; as suggested below, I did the cal and its loaded with V1.07)

« Last Edit: October 08, 2013, 12:49:51 pm by TonyGreene »
 

Offline gtroc71

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Re: $20 LCR ESR Transistor checker project
« Reply #164 on: October 07, 2013, 01:05:52 pm »
Hey Tony, my tester displays the version at the end of the calibration process.
Don't know if that is just the version I have (105) but I assume it works with all  :)
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #165 on: October 07, 2013, 11:48:21 pm »
I did a test, right out of the box, and here is the results, with no calibration;

I strongly recommend to run the self-adjustment. It measures the resistance and capacitance of the probes (incl. the PCB), internal IO port resistance, offsets of the bandgap reference and analog comparator and so on. Those values/offsets are stored in the EEPROM and will be taken into account for all new measurements which will be more precise. Without the self-adjustment some default values are used and they might not match your tester very well.

Please run the self-adjustment, re-run your tests and compare the results. And you'll will see :-)
« Last Edit: October 07, 2013, 11:55:23 pm by madires »
 

Online rastro

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Re: $20 LCR ESR Transistor checker project
« Reply #166 on: October 08, 2013, 10:07:34 am »
Another picture close up

I do plan to add the 2.5 volt reference and put the units in a case.


Tony, I probably missed something what is the 2.5 volt reference you're referring to.  Is it a modification instead of internal 328 reference?
 
 

Offline TonyGreene

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Re: $20 LCR ESR Transistor checker project
« Reply #167 on: October 08, 2013, 01:07:23 pm »
The 2.5V reference is discussed in chapter 2.1 and 2.4 of the V1.08 software, and maybe the same in previous versions.

Chapter 2.1 tells that an external voltage reference connected at pin PC4 can be used to check and calibrate the VCC voltage, but is not required for the basic operation of the Transistor/LCR tester.

Chapter 2.4 tells that sometimes with no connection to the pin, it may display unknown VCC voltage.  If this happens they recommend using a pullup resistor from the pin to VCC.  The pullup resistor keeps the processor from displaying the regulator output voltage.

The unit I received had no connection to pin 27.  I connected a 2.41K 0.5% resistor from the output of the +5 regulator to the cathode of the LM336Z-2.5 reference.  The anode of the reference is connected to ground.  Make a connection from the cathode of the reference to pin 27 of the ATmega328 and the unit will read the +5 volt regulator voltage.  And note this connection only works if you have the ATmega328 chip in the photo's I posted.  The connection is different depending on your ATmega328 chip package.

You don't need this, but its handy, you can run your battery all the way down until its starts affecting the +5 volt reference output.
 

Offline Napalm2002

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$20 LCR ESR Transistor checker project
« Reply #168 on: October 09, 2013, 03:55:31 am »
Bought one. Really like it and is definitely worth the few bucks that it costs.
 

Offline Napalm2002

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$20 LCR ESR Transistor checker project
« Reply #169 on: October 09, 2013, 03:59:34 am »
I was kicking around putting mine in an enclosure and putting leads on it. You did a nice job. Gonna have to get out the dremel tool and solder some stuff now
 

Offline TonyGreene

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Re: $20 LCR ESR Transistor checker project
« Reply #170 on: October 10, 2013, 11:22:34 am »
Here is a test of one of my units, I call it serial number 1.  The unit is cased and self-calibrated.

Test start 10/9/2013 17:41 71.5F    12V Battery
Test End 10/9/2013 19:12  72.0F

LM395 Matched Pair Transistor   Side A       B=1.03K Uf=619mV   
Unit 1                               Side B      B=1.03K Uf=614mV

LM395                                    Side A      B=860  Uf=614mV
Unit 2                               Side B      B=870  Uf=609mV

2N3904            NPN      B=168  Uf=716mV
Tung-Sol ET-1         PNP      B=89  Uf=117mV
2N2222            NPN      B=170  Uf=665mV
2N2907A            PNP      B=161  Uf=628mV
2N3440            NPN      B=101  Uf=576mv
2N5415            PNP      B=62  Uf=664mV
2N3054            NPN      B=38  Uf=584mV
2N3772            RESISTOR   1.29O
2SD91               NPN      B=89  Uf=516mV

MPF102            N-JFET   I=2.1mA Vgs=1.50
IFR820              N-E-MOS     C=829pF   Vt=3.32V
IFR510            N-E-MOS   C=437pF  Vt=3.14V

1N6263            DIODE   Uf=585mV  C=0pF
1N4148            DIODE   Uf=710mV  C=0pF
1N4001            DIODE   Uf=664mV  C=13pF
NTE5812            DIODE   Uf=590mV  C=163pF
1N5404            DIODE   Uf=584mV  C=49pF
1N3002            DIODE   Uf=642mV  C=408pF
1N1183A            DIODE   Uf=512mV  C=0pf
MBR10H100CT  Dual Diode   2*DIODE   UF=368mV  370mV

LM336Z-2.5V         DIODE   Uf=2.03V  C=0pF
LM4041BZ1.2V         2*DIODE   Uf=1.23V  796mV

Green LED            DIODE   Uf=1.96V  C=4pF
Yellow LED            DIODE   Uf=1.85V  C=4pF
Red LED            DIODE   Uf=1.60V  C=18pF
Red LED            DIODE   Uf=2.35V  C=49pF

IS420 SCR            NPN      B=29 UF=497mV

1,000,000 .01% WW         Resistor   1002K
100,000 .01% WW         Resistor   99.45K
10,000 .01% WW         Resistor   10.08K
1,000 .01% WW         Resistor   1003
100 .05% WW         Resistor   99.8
752.768 .02%    WW         Resistor   753.7
again                     753.7
again                     753.7
again                     753.7
again                     753.7
1 .5% WW                  1.67
10 .5% WW                  10.4
Shorted                  .55
9,100,000 1% WW               9346K
27,000,000 1% WW               26.87M

10pF               Unknown
22pF               Unknown
32pF Mica 5%         Capacitor   32pF
47pF Mica 5%               48pF
100pF Mica 5%               105pF
120pF Mica                  118pF
150pF Mica 5%               151pF
180pf Mica 10%               189pF
301pF Mica                  310pF
360pF Mica 5%               364pF
470pF Mica                  467pF
560pF Mica 5%               556pf
3000pf Mica 2%               3024pF
8200pf Mica 1%               8128pF
11000pf Mica 5%               10.45nF
15000pF Mica 5%               14.39nF
17000pF Mica 2%               16.91nF
33000pF Mica 5%               33.35nF
2.0uF Mylar 12.5%               2128nF  ESR=.66o
4.0uF Mylar 2%               4054nF  ESR=.63o Vloss=.1%
234uf Alum Electro NP 10%            235.1uF  ESR=.61o  Vloss=1%
470uF Alum Electro               495.7uF  ESR=.39o  Vloss=1.2%
1000uf Alum Electro               922.2uF ESR=.65o Vloss=.5%
3300uf Alum Electro               3364uF ESR=.61o  Vloss=1.2%
8000uF Alum Elctro               8999uF  ESR=.56o  Vloss=1.3%
10,000uF Alum Electro            11.81mF  ESR.59o  Vloss=1.6%
1uF Tant                  1020nF  ESR9.6o  Vloss=.3%

10uH                     .7o  L=.01mH
100uH                     1.6o L=.10mH
2.5mH                     19.2o  L=2.52mH
44mH 3%                  54.8o  L=40.0mH
50mH audio                  44.8o  L=49.9mH
30mH telephone               3.3o  L=28.4mH
120mH military               166.3o L=121mH
250mH Telephone               32.5o  L=244mH
720mH                  43.9o  L=689mH
8.3H 61o                  61.5o  L=8.50H

 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #171 on: October 10, 2013, 10:10:49 pm »
IS420 SCR            NPN      B=29 UF=497mV

Optical coupled TRIACs aren't supported yet :-)

Quote
Shorted                  .55

That's a little bit strange because the self-adjustment measures the resistance of the probes and the tester takes that into account when measuring resistors. Are you using probe leads? Have you done the self-adjustment with the probe leads attached?
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #172 on: October 22, 2013, 07:59:55 am »
Firmware News

Karl-Heinz finished version 1.08k (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/) with following highlights:
- support of DOG-M LCD modules with ST7036 controller
- measurement of leakage current for diodes and BJTs (used for hFE)
- 3 new UI languages
- several minor improvements

And I just released 1.10m (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/):
- 2.5V voltage reference (hardware option)
- protection relay for discharging caps (hardware option)
- Zener voltage measurement >4V (DC-DC boost converter hardware option)
- 16MHz MCU clock
 

Offline true

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Re: $20 LCR ESR Transistor checker project
« Reply #173 on: October 22, 2013, 02:24:43 pm »
Is there a page on differences between versions anywhere? Wiki? Something like that?

Should I make one? (not something I'd enjoy doing but it's info I would like to know anyway)
 

Offline Flump

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Re: $20 LCR ESR Transistor checker project
« Reply #174 on: October 22, 2013, 06:36:19 pm »
Can someone link to the best one of these to get please ?
 


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