$20 LCR ESR Transistor checker project

[madires]

This summer's release comes with just a few changes and improvements as the garden keeps me busy.

v1.44m:
- Added output of EIA-96 code for resistor E96 norm values (SW_R_E96_EIA96, suggested by Chris02@EEVblog).
- Added support for 4-line SPI to ILI9481 and ILI9486 drivers.
- Fixed timeout issue caused by ST7920 driver (reported by ralleeiner@mikrocontroller.net).
- Changed the discharge function: in case of a discharge problem the DUT's unloaded voltage is measured and displayed by the discharge error message, e.g. a battery's unloaded voltage.
- Fixed reversed diode symbol for second diode in output of anti-parallel diodes (reported by horo@EEVblog).
- Added option for low-active backlight to HD44780 driver for PCF8574 based I2C backpack (LCD_BACKLIGHT_LOW, suggested by Andreas Deimel).
- Fixed faulty symbols for p-channel MOSFETs in 24x24 symbol bitmaps (reported by Peeps@EEVblog).

Please download at:
- https://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware
- https://github.com/kubi48/TransistorTester-source/tree/master/Markus

[s_murat]

You will not accidentally have original English firmware 1.12k for gm328a?

[madires]

Have you already checked out https://disk.yandex.ru/d/yW8xa5NJgUo5z ?

[Dumidan]

Hello!

I checked the var_romanian.h file for version 1.44m and it is correct, no changes required.

Have a good day!

[de_light]

Hey guys, haven't posted on here for a while!

I'm trying to measure coil inductance with the tester project - is this possible? For example, I've wound a toroid on an Amidon T68-2 but whenever I connect it to my tester, it will only read a resistance. Even when I select LCR mode, it only reads a resistance.  Any suggestions?

[indman]

L measured if resistance below 2100 Ω

[de_light]

Strange. The measures resistance is around 1 ohm. It doesn't show any L values.

[indman]

de_light,what clone, what firmware is used? Show photos of the inductance and measure.

[madires]

The standard inductance measurement starts at about 10 µH for both OSHW firmwares. For lower values you can use the k-firmware's SamplingADC feature or the m-firmware plus the LC-meter hardware option.

[de_light]

Using v1.43m

The standard inductance measurement starts at about 10 µH for both OSHW firmwares. For lower values you can use the k-firmware's SamplingADC feature or the m-firmware plus the LC-meter hardware option.

Ah - this might be the issue. The inductances are low - around 1 uH

[Yuriy_K]

Ah - this might be the issue. The inductances are low - around 1 uH

If you use my firmware from page 277, you can get this result ...

[madires]

I've stumbled over LOPT/FBT testers (also called ring tester). It should be possible to design a simple hardware option for the Transistortester to do the same, i.e a test adapter for the three probes with a counter output for T0. Would you be interested in such a ring tester option?

[wandows]

Hello!

Sorry if I'm not posting in the correct thread.

Even without components shows the value of a capacitor, what's going on?

[madires]

Could be a SMPSU powering the tester or a damaged SRV05-4 (or damaged MCU pin).

[wandows]

Could be a SMPSU powering the tester or a damaged SRV05-4 (or damaged MCU pin).

But sometimes the tester works normally.
That's what intrigues me.

[Dumidan]

Hello!

Check if:
1. The PCB is clean in the lower area, where the ZIF socket and the input protection are located; preventively clean the place, on both sides, with isopropyl alcohol using a brush with soft and long threads.
2. soldering the components on the PCB, in the area mentioned above.

What do you supply the tester with? Is it somehow a switching source? The voltage of 12V is a bit high, I recommend 7 - 9V; you can use an IC like LM7808 or 7809 between the source and the tester. Even the low power version 78L08 / 78L09 works. At the output of the LM put a capacitor of 47 - 100 uF / 16V.

If both methods do not work, it may be a defective component, most likely SRV05-4 protection.

[indman]

wandows,In such cases, careful cleaning from dirt is helped, especially ZIF socket.
To check the results of cleaning and detecting problems with board in the firmware there are T1-T7 hardware tests.

[Dumidan]

I've stumbled over LOPT/FBT testers (also called ring tester). It should be possible to design a simple hardware option for the Transistortester to do the same, i.e a test adapter for the three probes with a counter output for T0. Would you be interested in such a ring tester option?

Yes; part of Bob Parker's scheme can be used. I will draw the portion I am thinking of and I will post it as soon as possible.

I tested the 1.13k version on my AY-AT and I liked the method of measuring the inductance using a standard (etalon) capacitor; can you add it in your next version?

[madires]

Sampling-ADC? Maybe in the future, but not now (lack of time).

[wandows]

Hello!

Sorry if I'm not posting in the correct thread.

Even without components shows the value of a capacitor, what's going on?

Hello friends!

Thanks for the valuable help in solving my tester's problem.

A thorough cleaning of the Zif socket and Srv-05 was enough to stabilize the device's operation.

Thank you all!!!

[wandows]

Hello everyone!!!
I have a device that was damaged by not discharging the electrolytic capacitor before testing.
I know when this happens the SRV-05-4 is damaged and must be replaced.
MCU gets damaged?, or just install the firmware?

[madires]

The SRV-05-4 is optional, i.e. the tester will run also without it. Remove the SRV-05-4 and check if the tester runs. If that doesn't help also remove the TVS and test again.

[Dumidan]

I've stumbled over LOPT/FBT testers (also called ring tester). It should be possible to design a simple hardware option for the Transistortester to do the same, i.e a test adapter for the three probes with a counter output for T0. Would you be interested in such a ring tester option?

Yes; part of Bob Parker's scheme can be used. I will draw the portion I am thinking of and I will post it as soon as possible.

Hi!

I had some time and drew two variants for the LOPT / FBT test adapter.

Both variants are designed by Bob Parker and can be found on the internet. The tester is well documented and explained. Bob also made a more complex version, based on a PIC MCU.
I built Bob's tester, the LM393 and CD4015 version and it works very well.

[Feliciano]

I've been following this long thread for years, and want to thank Karl-Heinz, the two Markus, indman, and the whole crew.

I have had a dozen of these component testers (haven't burn any, knock on wood), and I currently have a a T4, a TC1 (wondering how a recent m-firmware would look running on it), and other one I don't recall anyone reviewing it here, so here I go:

The PCB states WEI_M8_shell_TST. It has a 3.7V battery with a physical switch, a Mega328p, an 8MHz crystal, several scratched ICs, and 3 nice test leads plus a ZIF socket with extra PCB options, a monochrome graphics (don't know the controller). The 1.11k firmware was modified by VANVELL ELC.
I have used it for testing quite a lot of components without problems, and I'm happy with it. Nevertheless, I wonder whether somebody already updated the (k or m) firmware for it, although I've not studied how to connect the programming interface yet. Shall somebody already acmomplished this, please point me to the right place. (I could also remove/replace the 431 and try to switch to a 16MHz crystal, but first thing first).

I attach some pictures.

[indman]

Feliciano,You have one of the numerous variants of the Chinese clone Wey_m8. For this clone should be firmware that lie in the "MG328" and "328WEY M8" folders on my resource https://yadi.sk/d/yW8xa5NJgUo5z