Author Topic: $20 LCR ESR Transistor checker project  (Read 3361838 times)

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Offline timelessbeing

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Re: $20 LCR ESR Transistor checker project
« Reply #4425 on: January 31, 2018, 06:43:06 pm »
Computers have this awesome ability called "search".
 

Offline rddube

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Re: $20 LCR ESR Transistor checker project
« Reply #4426 on: January 31, 2018, 07:22:06 pm »
Sorry, I don't provide compiled firmware because there are too many different hardware versions. The links for the latest firmware versions:
- k-firmware: https://github.com/svn2github/transistortester/tree/master/Software/trunk
- m-firmware: https://github.com/svn2github/transistortester/tree/master/Software/Markus

Ok, Madires, I understand. Is there a guide somewhere for which version matches which type of screen? My machine is like one of the first ones, sold in kit on BangGood with the 2 line display. Would that be the default version?

Tks again!
 

Offline imidis

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Re: $20 LCR ESR Transistor checker project
« Reply #4427 on: January 31, 2018, 07:45:07 pm »
Easiest way to identify is look for a similar image to yours then the display listed or look at the driver chip, I think yours is the 1602 LCD which is 2 line 16 character, so I would think 2x16_menu may work.
Gone for good
 

Offline kelchm

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Re: $20 LCR ESR Transistor checker project
« Reply #4428 on: February 01, 2018, 06:05:32 am »
Computers have this awesome ability called "search".
Have you ever actually tried searching on this forum? You're better off using Google along with the title of the thread.
 

Offline timelessbeing

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Re: $20 LCR ESR Transistor checker project
« Reply #4429 on: February 01, 2018, 07:16:38 am »
@kelchm
The forum search (ie the one in the screenshot i posted) worked just fine for finding the firmware link.
 

Offline hussamaldean

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Re: $20 LCR ESR Transistor checker project
« Reply #4430 on: February 01, 2018, 09:15:19 am »
Hi,
I have one of these in the picture and it is T5
but it doesn't work and the screen is blank
any hope to solve it ?
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4431 on: February 01, 2018, 10:36:38 am »
Get the schematic, grab a DMM and start checking ;)
 

Offline hussamaldean

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Re: $20 LCR ESR Transistor checker project
« Reply #4432 on: February 01, 2018, 10:47:41 am »
Get the schematic, grab a DMM and start checking ;)
let me explain
when I press the button, the screen lit and off
it was working and was so slow and when calibrate it, kaboom everything gone
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4433 on: February 01, 2018, 01:31:59 pm »
Possibly wrong fuse settings (CKDIV8 set/programmed).
 

Offline hussamaldean

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Re: $20 LCR ESR Transistor checker project
« Reply #4434 on: February 01, 2018, 01:50:39 pm »
Possibly wrong fuse settings (CKDIV8 set/programmed).

I tried but I can't change the fuse registry either
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4435 on: February 01, 2018, 02:04:08 pm »
Is the ATmega write protected (lock bits set)?
 

Offline hussamaldean

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Re: $20 LCR ESR Transistor checker project
« Reply #4436 on: February 01, 2018, 02:11:25 pm »
Is the ATmega write protected (lock bits set)?
LB is 0x3F
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4437 on: February 01, 2018, 02:25:23 pm »
If there's nothing wrong with your programming it seems to be a bad ATmega.
 

Offline Gregi

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Re: $20 LCR ESR Transistor checker project
« Reply #4438 on: February 01, 2018, 05:18:48 pm »
I have just finished my tester today and it worked for about 2 seconds. It was powered with 10v supply from my psu and said low batt voltage 6.8X volts and then shuts off. Ofc it wont turn on anymore even on 9V battery. Red LED is not on, display is black. any ideas what to check?

i bought this one
Link to aliexpress
« Last Edit: February 01, 2018, 05:21:53 pm by Gregi »
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4439 on: February 01, 2018, 05:36:14 pm »
That's an AY-AT (schematic in this thread) and typical problems are a reversed SVR05-4 or a bad transistor in the power circuitry.
 

Offline Gregi

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Re: $20 LCR ESR Transistor checker project
« Reply #4440 on: February 02, 2018, 08:44:53 am »
Can I use 78L05 instead of HT7550? HT7550 is not available in TO92 package except from china.
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4441 on: February 02, 2018, 10:48:12 am »
Yes, but a MCP1702-5002 would be better.
 

Offline Gregi

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Re: $20 LCR ESR Transistor checker project
« Reply #4442 on: February 02, 2018, 02:41:57 pm »
I have tested the voltages in the circuit and i had 0.2 volts on the out pin of ht7550 so i removed it and tried with 78L05 (thats what i had in my workshop) and it works. So 7550 worked for 2 seconds and died :)
 

Offline GBowes

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Re: $20 LCR ESR Transistor checker project
« Reply #4443 on: February 03, 2018, 12:03:52 am »
Glad you got it working.
Pinout is very different between HT7550 and 78L05. Could you have put the 7550 in wrong? I have done it more than once with these newer regulators.

As Markus mentioned, MCP1702-5002 would be much better (results more accurate). BTW, it has the same pinout as the HT7550

Graham


I have tested the voltages in the circuit and i had 0.2 volts on the out pin of ht7550 so i removed it and tried with 78L05 (thats what i had in my workshop) and it works. So 7550 worked for 2 seconds and died :)
 

Offline dave356

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Re: $20 LCR ESR Transistor checker project
« Reply #4444 on: February 03, 2018, 06:59:30 am »
Hi Guy's

I just purchased 2 of the AY-AT testers (1 kit, 1 assembled) and am going to install some better components.

  680ohm  0.1%
470kohm  0.1%
LM4040 2.5v ref
MCP1702 5v reg

I have also ordered 4 extra ATMEGA328 chips so I can try different FW versions
without overwriting original. (And to have spares)

Can I also install a 16mhz crystal with stock firmware or will I have to reflash.
Will stock firmware work with a 16mhz crystal???

Anything else to replace to improve accuracy?


Thanks


 

Offline perieanuo

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Re: $20 LCR ESR Transistor checker project
« Reply #4445 on: February 03, 2018, 01:55:36 pm »
Hi Guy's

I just purchased 2 of the AY-AT testers (1 kit, 1 assembled) and am going to install some better components.

  680ohm  0.1%
470kohm  0.1%
LM4040 2.5v ref
MCP1702 5v reg

I have also ordered 4 extra ATMEGA328 chips so I can try different FW versions
without overwriting original. (And to have spares)

Can I also install a 16mhz crystal with stock firmware or will I have to reflash.
Will stock firmware work with a 16mhz crystal???

Anything else to replace to improve accuracy?


Thanks
1.yes, have to reflash.
2.yes,it will work, but incorrectly

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4446 on: February 03, 2018, 03:05:25 pm »
Can I also install a 16mhz crystal with stock firmware or will I have to reflash.
Will stock firmware work with a 16mhz crystal???

You need to change the MCU clock in the source code to 16MHz (Makefile) and compile a new firmware.
 

Offline pappkopp

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Re: $20 LCR ESR Transistor checker project
« Reply #4447 on: February 03, 2018, 03:57:43 pm »
Is pd6 supposed to have power the whole time? My wont stay on unless i hold the button down..
 

Offline kelchm

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Re: $20 LCR ESR Transistor checker project
« Reply #4448 on: February 03, 2018, 04:44:35 pm »
Code: [Select]
AVR Memory Usage
----------------
Device: atmega328

Program:   36136 bytes (110.3% Full)
(.text + .data + .bootloader)

Data:        257 bytes (12.5% Full)
(.data + .bss + .noinit)

EEPROM:      882 bytes (86.1% Full)
(.eeprom)

Using 1.31m and the IR options sure do eat up a lot of space on the lowly ATMega328p... I'd really love to build one of the ATMega1284 variants, but I really don't want to spend close to $100 getting the boards made. Has anyone set up a group buy for these in the past?
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4449 on: February 03, 2018, 05:51:39 pm »
Is pd6 supposed to have power the whole time? My wont stay on unless i hold the button down..

Using the 328 standard pin assignment PD6 switches the power, i.e. the pin is set high by the MCU at start-up.
 


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