$20 LCR ESR Transistor checker project

[Yuriy_K]

FWIW, I ran the ESR test through a series of film Capacitors. The trend seems logical to me, what I was discussing was the differences

At the beginning of the work on upgrading the k-firmware, I compiled similar graphs. I hoped to find the dependence of ESR on capacitance, but when analyzing different types and models of capacitors, I realized that the idea was a dead end. A larger capacitance may have a higher ESR value. Here is an example of measurements for capacitors of 1 µF and 0.47 µF.

[Calambres]

Just got one of these:

https://www.ebay.com/itm/142849416622?var=441847192858

Seems to be a new variant of the AY-AT board (8MHz) with Atmel chip. Once calibrated it is very accurate... surprisingly accurate if you ask!

[Messtechniker]

It's always a good idea to have the micro socketed.
And a few spares around too.

[BILLPOD]

Just got one of these:

https://www.ebay.com/itm/142849416622?var=441847192858

Seems to be a new variant of the AY-AT board (8MHz) with Atmel chip. Once calibrated it is very accurate... surprisingly accurate if you ask!

That was the description of the one I got from Amazon, but mine has the ATP32F172K8T6 Chinese chip.   Same clear DIY case.

[Feliciano]

At the beginning of the work on upgrading the k-firmware, I compiled similar graphs. I hoped to find the dependence of ESR on capacitance

I read some post you made about this topic on mid-2022, and I tried to retake that line to prove a)there's a relationship, and more important to me, b)the difference between k-firmware and m-firmware approach.

For the first test, I selected some Capacitors from the same vendor, same batch, same voltage range (63V-100V), and the results were very nice IMO. For the second test, I took a blind approach (like the practical scenario for the repair shop): different vendors, different ages, different voltages, so I expected high discrepancies, which in fact ocurred but not enough to discard the idea IMHO. I suppose if somebody repeat the exercise with same brand and voltage Capacitors, a more evident trend can be obtained. Lastly, I notice the measurements differences between k-firmware and m-firmware, the values are more similar for this escenario (being the m the more consistent), but the slope of m-firmware is higher, confirming the observations of the first test.

[Calambres]

Just got one of these:

https://www.ebay.com/itm/142849416622?var=441847192858

Seems to be a new variant of the AY-AT board (8MHz) with Atmel chip. Once calibrated it is very accurate... surprisingly accurate if you ask!

That was the description of the one I got from Amazon, but mine has the ATP32F172K8T6 Chinese chip.   Same clear DIY case.

The kit includes 2% 1/8W resistors. I have checked them all and had to substitute some of them because they were beyond the 2% limit. I bet they're factory rejects to reduce costs...

The chip seems to be a legit ATMEL but nowadays who knows...

As I said in my previous port, once calibrated it is quite precise. I compared results with my DER DEE-5000 for resistors, capacitors and inductors and with my Peak Atlas DCA55 for semiconductors.

[SA]

I fried my TC1 by charged capacitor. I have replaced the damaged components. The DIP MCU is also damaged. Is any firmware available for TC1 with atmega 328p? Attached picture is similar to my unit. I am not an expert, it would be great if there is hex file available....

[carl1961]

I fried my TC1 by charged capacitor. I have replaced the damaged components. The DIP MCU is also damaged. Is any firmware available for TC1 with atmega 328p? Attached picture is similar to my unit. I am not an expert, it would be great if there is hex file available....

Maybe start here, seems to be your model

https://www.eevblog.com/forum/testgear/tc1-lcr-meter-transistor-tester-fix/225/

[Yuriy_K]

Some types of film capacitors have specific frequency characteristics. For comparison, I showed these characteristics in comparison with the readings of the k-firmware. The points on the graphs correspond to frequencies of 1,5,10,20,40,60,80,100 kHz

[Feliciano]

Absolutely, that's why is important -if we want to find trends- select same type of Capacitor, same Voltage range, and if possible, same vendor and batch (which I did for my first graph and not for the second).

[indman]

For low value capacitors it's better to use an LCR/ESR meter to measure the ESR.

I fully support that opinion. The use of a transistor tester to evaluate the quality of ceramic, film and other similar types is purely indicative and can very often misjudge such capacitors. There's no point in citing specs and graphs. It's easy enough to compare a few of the different types I listed above with a professional LCR meter to realize this. The difference between real ESR and tester readings can be 10-1000 times! Capacitance and ESR measurements a transistor tester are purely bonus in nature and are only good for monitoring ELECTROLYTIC capacitors.

[rsjsouza]

I personally find the tan(delta) or D (dissipation factor) a more convenient measure, as it is independent on the capacitance. Also, given it is specified in the datasheets, it becomes a more certain method to evaluate the state of a capacitor.

[indman]

I personally find the tan(delta) or D (dissipation factor) a more convenient measure, as it is independent on the capacitance. 

Exactly, I agree with you, but unfortunately, this parameter can only be measured correctly by a full-fledged LCR meter.
The tester will not be able to do this.

[carl1961]

Latest retirement Project, following  von Boleslaw J. great work, except the 2.8" TFT is in case with the AY-AT Board

[Boleslaw_J]

Got JLC making von Boleslaw J. (boleslaw_43) Adapter_328-644_106_quartzw  there still in production, takes like 2-3 weeks before I get them. they or 5 on a part, so 25 total!  anyone who want's one, there free for the taking (20) just pay shipping (self return stamped envelope) C1 100uf,  R1 360 ohm,  C2 C3 22p

Should be C1 100 nF, R1 680 Ohm.

Well done! I like it. Powered by a rechargeable battery, charged via USB socket.

[carl1961]

Got JLC making von Boleslaw J. (boleslaw_43) Adapter_328-644_106_quartzw  there still in production, takes like 2-3 weeks before I get them. they or 5 on a part, so 25 total!  anyone who want's one, there free for the taking (20) just pay shipping (self return stamped envelope) C1 100uf,  R1 360 ohm,  C2 C3 22p

Should be C1 100 nF, R1 680 Ohm.

Well done! I like it. Powered by a rechargeable battery, charged via USB socket.

Thanks, I changed those values in the post.     soon as I verify the Enclosure Case I will share the stl and Cad Files

[Kim Christensen]

indman & Feliciano,
Thanks for the FNIRSI m-firmware adaptation. It works for my unit as well. (I left the STC in circuit)
If it's not too much trouble, can you post the source code which you used to compile the "LCR-TC1 FNIRSI 1.51mEn(SPI bitbang).zip" HEX & EEP files as per your earlier post?

[Feliciano]

If you want the binaries, indman shared some a few days back (I asume that's the one you're running?). He also has the more polished version of the schematic. 2hry also shared key configuration and binaries to help accelerate this development.

Nevertheless, if you want to adapt the code to you liking, my m-firmware device_specific configuration is:

Code: [Select]

MCU = atmega324p
FREQ = 16
PARTNO = m324pa


Code: [Select]

#define HW_ZENER
#define ZENER_R1         100000
#define ZENER_R2         12000
#define ZENER_UNSWITCHED
#define HW_PROBE_ZENER
#define ZENER_VOLTAGE_MIN     1000      /* min. voltage in mV */
#define ZENER_VOLTAGE_MAX     22000     /* max. voltage in mV */
#define HW_IR_RECEIVER
#define HW_ADJUST_CAP
#define BAT_DIRECT
#define BAT_OFFSET       0


Code: [Select]

#define LCD_PORT         PORTB          /* port data register */
#define LCD_DDR          DDRB           /* port data direction register */
#define LCD_RES          PB4            /* port pin used for /RESX (optional) */
#define LCD_DC           PB3            /* port pin used for D/CX */
#define LCD_SCL          PB7            /* port pin used for SCL */
#define LCD_SDA          PB5            /* port pin used for SDA */
#define LCD_DOTS_X       128            /* number of horizontal dots */
#define LCD_DOTS_Y       160            /* number of vertical dots */
#define LCD_OFFSET_X     2               /* enable x offset of 2 or 4 dots */
#define LCD_OFFSET_Y     1               /* enable y offset of 1 or 2 dots */
#define LCD_FLIP_X                      /* enable horizontal flip */
#define LCD_ROTATE                      /* switch X and Y (rotate by 90°) */

#define ADC_PORT         PORTA     /* port data register */
#define ADC_DDR          DDRA      /* port data direction register */
#define ADC_PIN          PINA      /* port input pins register */
#define TP1              PA0       /* test pin / probe #1 */
#define TP2              PA1       /* test pin / probe #2 */
#define TP3              PA2       /* test pin / probe #3 */

#define TP_ZENER         PA4       /* test pin for for Zener check (10:1 voltage divider) */
#define TP_REF           PA3       /* test pin for 2.5V reference and relay */
#define TP_BAT           PA5       /* test pin for battery (4:1 voltage divider) */
#define TP_CAP           PA7       /* test pin for self-adjustment cap */
#define R_PORT           PORTC     /* port data register */
#define R_DDR            DDRC      /* port data direction register */
#define R_RL_1           PC0       /* Rl (680R) for test pin #1 */
#define R_RH_1           PC1       /* Rh (470k) for test pin #1 */
#define R_RL_2           PC2       /* Rl (680R) for test pin #2 */
#define R_RH_2           PC3       /* Rh (470k) for test pin #2 */
#define R_RL_3           PC4       /* Rl (680R) for test pin #3 */
#define R_RH_3           PC5       /* Rh (470k) for test pin #3 */
#define POWER_PORT       PORTD     /* port data register */
#define POWER_DDR        DDRD      /* port data direction register */
#define POWER_CTRL       PD7       /* control pin (1: on / 0: off) */
#define BUTTON_PORT      PORTB     /* port data register */
#define BUTTON_DDR       DDRB      /* port data direction register */
#define BUTTON_PIN       PINB      /* port input pins register */
#define TEST_BUTTON      PB2       /* test/start push button (low active) */
#define IR_PORT          PORTD     /* port data register */
#define IR_DDR           DDRD      /* port data direction register */
#define IR_PIN           PIND      /* port input pins register */
#define IR_DATA          PD3       /* data signal */
#define ADJUST_PORT      PORTC     /* port data register */
#define ADJUST_DDR       DDRC      /* port data direction register */
#define ADJUST_RH        PC6       /* Rh (470k) for fixed cap */


[Kim Christensen]

Feliciano,
Yes, I'm running the firmware uploaded by indman. (LCR-TC1 FNIRSI 1.51mEn(SPI bitbang).zip)
The schematic will be helpful as well so I've also saved a copy of that. Thanks.
One thing I did notice with this version is that there is a discrepancy in the capacitance measured depending on what mode it is operating in. Does your unit also show vastly different capacitance readings between "Probing..." mode and "LCR Monitor" mode for certain values? I did perform both a "Test" and an "Adjustment" thinking that was the issue but it wasn't. For example this is what I measured in uF:

Cap       "Auto"   "LCR mon"
1uF        1.039    1.038
10uF      9.929    9.953
39uF      36.29    37.02
120uF    99.79    120.1
270uF    155.6    262.5
680uF    328.3    599.5
1000uF  392.9    932.0
3900uF  3017     3657

[indman]

Does your unit also show vastly different capacitance readings between "Probing..." mode and "LCR Monitor" mode for certain values? I did perform both a "Test" and an "Adjustment" thinking that was the issue but it wasn't.

No,there shouldn’t be such a big difference in the readings! It is not normal. I wonder what the results will be on the Feliciano clone?

[Yuriy_K]

Does your unit also show vastly different capacitance readings between "Probing..." mode and "LCR Monitor" mode for certain values? I did perform both a "Test" and an "Adjustment" thinking that was the issue but it wasn't.

I also have a difference in readings, but not so significant...

[Feliciano]

I think something is not quite right with m-firmware for large Capacitors, at least for 1.51m, and for this new TC1 variant. Has somebody tried an older version?

[indman]

I think something is not quite right with m-firmware for large Capacitors, at least for 1.51m, and for this new TC1 variant. Has somebody tried an older version?

I think that the issue is not the new or old version of m-firmware, but the fact that your FNIRSI clone tests electrolytes completely differently from Kim Christensen. I think that there is some other hardware difference from the standard in these clones that does not allow the firmware to function normally. Or the firmware is not yet fully adapted.

[Feliciano]

It could be either one: hardware or firmware. That's the thing to determine now. But the odd part here is that the failure seems to be LCR-Monitor specific, not normal DUT measurements 

Regardless, one approach could be to check with older m-firmware, other it could be check your later schematic (could you please share it with me?) against the PCB and against the configuration files.

[indman]

Updated diagram in my post
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg5335865/#msg5335865
If you have the desire and time, then check again whether it corresponds to the real scheme of your clone?