$20 LCR ESR Transistor checker project

[TheBay]

I'm just going to buy another one.  I really like the unit and it was pretty accurate.   They were not kidding when they say, "Discharge Capacitors".  I just plugged in a capacitor after just testing it.  It still had a charge in it.

I am surprised nobody has thought of putting a strip of tinned PCB above the jacks, under the discharge warning.   

Good shout that! On my MK-328 there is a slot cut out for something, I'll put a blank PCB behind there and cut the label through.

[bitseeker]

I am surprised nobody has thought of putting a strip of tinned PCB above the jacks, under the discharge warning.   

Good shout that! On my MK-328 there is a slot cut out for something, I'll put a blank PCB behind there and cut the label through.

Good idea. That case has lots of space for stuff.

[Back2Volts]

I am surprised nobody has thought of putting a strip of tinned PCB above the jacks, under the discharge warning.   

Please see below the pin header labeled DUT:

Great device area design !

[almamater]

Hello, i bought this 2016 EZM328 transistor tester KIT:

With V1.12K software and M328 chip.

How can we put the components at the right place? (example: match the resistors with the number\label @ the board: R1, R2, R3..etc).

Can i use the schematic "New Circuit of Transistor Tester" in the ttester.pdf manual (page 10)?

[vinceroger]

Hello, i bought this 2016 EZM328 transistor tester KIT:

With V1.12K software and M328 chip.

How can we put the components at the right place? (example: match the resistors with the number\label @ the board: R1, R2, R3..etc).

Can i use the schematic "New Circuit of Transistor Tester" in the ttester.pdf manual (page 10)?

i have two of these testers if you read back a few pages stj helped me with the parts list and what went where etc its all in this thread including the firmware too as most of these tester have come with no firmware anything you need too know just ask

edit here you go should help you
----------------------------------------
r1 - 680r sensing circuit
r2 - 470k sensing circuit
r3 - 680r sensing circuit
r4 - 470k sensing circuit
r5 - 680r sensing circuit
r6 - 470k sensing circuit
r7 - 10k reset pullup
r8 - 33k power control
r9 - 3k3 power control
r10 - 27k
r11 - 100k (says r1 but is next to r10)
r12 - 10k voltage divider for battery sense
r13 - 3k3 voltage divider for battery sense
r14 - 560r display related - led current limit
r15 - 27k
r16 - 0r jumper for AVCC
r17 - 2k2 from tl431 to vcc
r18 - 1k rotary encoder current limit
r19 - 1k rotary encoder current limit
r20 - 10k rotary encoder pullup
r21 - 10k rotary encoder pullup
r22 - 470r frequency input dropper
r23 - 10k frequency input voltage divider
r24 - 10k frequency input voltage divider

rv1 - 10k preset frequency input voltage divider

u3 = tl431

q1 - 4673 (bc557c)
q2 - c945 (bc547)
q3 - c945 (bc547)

c1 - 22pf for crystal
c2 - 22pf for crystal
c3 - 100nf
c4 - 10nf
c5 - 10uf 16v
c6 - 10uf 16v
c7 - 100nf
c8 - 100nf
c9 - 100n frequency input DC blocker

and post 349 in this thread has a good picture you can zoom in on and see the colours of the resistors if needed
http://www.badcaps.net/forum/showthread.php?t=50720&highlight=esr+tester&page=18

[almamater]

     uouu! Thank you so much! I searched in this thread.. and i did not found this info. Sorry, my bad.
Thank you

[vinceroger]

    uouu! Thank you so much! I searched in this thread.. and i did not found this info. Sorry, my bad.
Thank you

Build the kit up and let us know how you get on what a lot of people have found is that these testers dont come with firmware on the atmega 328p ic so we have to re programe it ourselves but you may be lucky once you have built it let us know how you get on you will also need to calibrate it too once built.

[madires]

It's alive. The 324/644/1284 dev board is running a preliminary 1.25m.

[PedroDaGr8]

It's alive. The 324/644/1284 dev board is running a preliminary 1.25m.

I can't wait for this to trickle out. I know this is a huge undertaking so I am waiting for this to complete before I buy one of these.

[Nawual]

Hi!,i want to buy one,any device?

Thanks

[almamater]

Build the kit up and let us know how you get on what a lot of people have found is that these testers dont come with firmware on the atmega 328p ic so we have to re programe it ourselves but you may be lucky once you have built it let us know how you get on you will also need to calibrate it too once built.

Hello, it is done, I soldered all components, a few photos:












Differences:
The C5 and C6 capacitors, in the STJ list they are 10uF 16v caps, but i have received 100uF 25v. The seller gave me this PDF: Link

Now is time to connect a 9v battery and see what happens!

[vinceroger]

Build the kit up and let us know how you get on what a lot of people have found is that these testers dont come with firmware on the atmega 328p ic so we have to re programe it ourselves but you may be lucky once you have built it let us know how you get on you will also need to calibrate it too once built.

Hello, it is done, I soldered all components, a few photos:












Differences:
The C5 and C6 capacitors, in the STJ list they are 10uF 16v caps, but i have received 100uF 25v. The seller gave me this PDF: Link

Now is time to connect a 9v battery and see what happens!

Hopefully yours will have the firmware on it already i have two of these testers one is all original as in 8 mhz crystal and original firmware the second one ive modded a bit has 16 mhz crystal a diffrent voltage regulator and a copy of the version 2 16 mhz firmware.

[almamater]

Yes it have Firmware! It says that i must calibrate first..

[vinceroger]

Yes it have Firmware! It says that i must calibrate first..

Thats great they may of sorted the issue out then too calibrate just put a capacitor to pin 1 and pin 3. This capacitor
should have a good quality factor and should have a capacity between 100nF and 20µF. It should
be a film capacitor. (copied from tester manual pdf)

[almamater]

Ok, the Firmware asks to short the probes (3), then to isolate them and dont asks for any capacitor..

With a multimeter and one 6800uF capacitor, i read ~6480uF. With this tester i read ~6600uF.

[vinceroger]

ok just checked my origanal tester try going into self test using rotery encoder with all three probes shorted then it will say issolate probs do that then after a few more tests it will say 1-3 100nf add the cap then and let test run

[madires]

It's alive. The 324/644/1284 dev board is running a preliminary 1.25m.

After testing most stuff I've released 1.25m:
- A lot of changes to support the ATmega 324/644/1284.
- Modified test resistor management to support variable port pins.
- Added software option for probe color coding.
- Centralized color management.
- Added file listing settings for various tester versions/clones.
- Fixed small issue with 24x24 VP symbol bitmap in config.h. Reported by
  lordstein@EEVblog and hapless@EEVblog.

I had a quick look into the ESR issue with the 220nF cap and 16MHz MCU clock. I got one tester with the same issue, but also two which are fine (328@20MHz and 644@16MHz). Some fringe case?

For the next version I plan to add some 324/644/1284 specific features, like hardware SPI.

[milamber]

Hi, I am using the AY-AT with "AY-AT ESR tester (SVN684) - v2.zip" with 16MHz Quarz.

The unit wants to calibrate nearly every second measurement / button press after turning it on. Even if I finish the calibration successfully, turn it off (without unpowering) and turn it on again.

Is that normal?

[madires]

Have you done the calibration as explained in Karl-Heinz' documentation?

[milamber]

Have you done the calibration as explained in Karl-Heinz' documentation?

I only followed the instructions displayed on the device display: 
- short all 3 pins for calibration
- remove the wiring
wait for the calibration success message. Tried that several times because selftest was automatically issued again.

Now I RTFM, startet the calibration from the menu, added a 220nf and 22nf ceramic capacitor during test and everything seems to work fine. 
Thanks for the hint.

[Nawual]

Hello, i want to buy one but I can not decide, any suggestion?

Thanks

[bitseeker]

Hello, i want to buy one but I can not decide, any suggestion?

Hi Nawual. Welcome to the forums. Here's a recent summary of the prevalent versions, which might help you narrow down what you like:

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1023260/#msg1023260

[madires]

I think, you've copied your old config_328.h. Replace "LCD_ST7735_SPI" with "LCD_ST7735" and add:

Code: [Select]

#define LCD_SPI_BITBANG                 /* bit-bang SPI interface */

Please see Clones for the settings. Those changes are made to support bit-bang and hardware SPI in the next version, simply by setting LCD_SPI_BITBANG or LCD_SPI_HARDWARE. The ATmega328 based testers can only use bit-bang SPI.

Edit: OP deleted his post, but my answer will stay, just in case someone else runs into the same issue.

[indman]

Hi, madires! Thank you for the new version! I deleted the post because itself dealt with a problem. Everything is normally compiled.

[packetbob]

I started reading this thread around the time flywheelz posted about the one he bought:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1007286/#msg1007286

I thought it would be pretty handy so I ordered one from the same place...
Some how it managed to get to me less than 3 weeks after I ordered it....

Based on flywheelz experience I was paranoid about getting the SRV05-4 diode array correctly oriented. Mine had the smallest of little specs to indicate pin 1. I double it checked against what flywheelz mentions here about identifyign the pins:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1008486/#msg1008486

It worked as soon as I powered it up. Then I decided that I should try some of the other firmware and boost the clock speed. So I replaced the 8 Mhz crystal with a 16 Mhz. I then followed flywheelz note in this message to wire up some header pins and use an Aruduino UNO as a programmer:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1021401/#msg1021401

I then used the 16 Mhz version of the firmware I found here: (Updated with correct link 09/27/2016)
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1009936/#msg1009936

Everything seems to work like a charm. However since I figured that the existing ATMEGA328P chip may be marginal at the higher speed I used a new 328P that I had. This way I also had the working code on the original chip in the event I borked it all up. I did clean off the flux from soldering with isopropyl alcohol. And while I didn't think I needed a case for it I did end up mounting it on a piece of 1/4" MDF along with a clip to hold the battery and a piece of aluminum strip to short out caps before testing them. And some labels... And I bought a knob for the encoder...

Going forward, I need to read through the thread again to figure out what other versions of the software exist (it is a long thread) and play with them. I believe I am using stj's SVN684 right now.

I case you noticed the big ass'd transistor I am testing in the pictures. It is a 2N107. One of the first electronics projects I ever built was a small transistor amplifier back in the early 70's. It was based on a circuit that I believe I got from The Boy's Third Book of Radio and Electronics (by Alfred Morgan). Don't have the amplifier anymore but still have a couple working 2N107s (according to the testor!!!)

My thanks to everyone that added to this thread.....