Dally, Shark & Ruslan workbench

[Itsu]

pin 10 and 12 of U7 (IR2110)  are resp. 0V and 12V

Will try the U7 out and its pin 1 (not pin 7) to +15V later.        (Pin 1 goes to gate Q3, see below diagram which is as i have it now)

Itsu

[Itsu]

I pulled out U7 (IR2110) and pulled up pin 1 to +15V using a 1K resistor.

I have a 1 Ohm 1% inductionfree resistor (csr) in the collector lead coming from the primary coil and measure 428mV across it, pointing to 428mA going through this primary.
The 12.8V collector PS shows 360mA, so i am not sure what is the most accurate value.


I had to remove the ground wire from the circuit as the scope probe ground lead would have caused a shortout.

Itsu

[Vasik041]

I pulled out U7 (IR2110) and pulled up pin 1 to +15V using a 1K resistor.
I have a 1 Ohm 1% inductionfree resistor (csr) in the collector lead coming from the primary coil and measure 428mV across it, pointing to 428mA going through this primary.
The 12.8V collector PS shows 360mA, so i am not sure what is the most accurate value.
I had to remove the ground wire from the circuit as the scope probe ground lead would have caused a shortout.
Itsu

I have similar looking voltage/current indicators from ebay, they are not very accurate.
400ma probably to high for 12v, for beginning I would suggest increasing slightly R17 so that current decrease to 100-200ma (not sure).

Vasik

[Itsu]

I agree,   i will change R17 to a 5K potmeter to adjust to 100-200ma

Itsu

[Verpies]

Pin 1 has 0V   same as pin 7.

IF
pins 3, 9 are at +15V, and
pin 2, 11, 13 are grounded, and
pin 12 is at +12V

THEN
pin 1 must be at +15V unless something is pulling it down drastically ...or the IR2110 chip is broken.

[Itsu]

Ok,  i will check again the pin 1 value tomorrow.


In de mean time i added a 5K pot in series with R17 (3.3K) and had to use the whole range (5K) to get to 150mA collector current at 12V.
This means that R17 should be in the 8K range.

Itsu

[AlienGrey]

IF
pins 3, 9 are at +15V, and
pin 2, 11, 13 are grounded, and
pin 12 is at +12V

THEN
pin 1 must be at +15V unless something is pulling it down drastically ...or the IR2110 chip is broken.

You need to pull up pin 6

Quote from: Itsu on 2021-06-11, 17:15:41

    Pin 1 has 0V   same as pin 7.

IF you missed out pin 6 , 3, 9
pins 3, 9 are at +15V, and
pin 2, 11, 13 are grounded, and
pin 12 is at +12V

THEN
pin 1 must be at +15V unless something is pulling it down drastically ...or the IR2110 chip is broken.  may be not!

[Verpies]

You need to pull up pin 6

Why?
Pin 6 is the high supply for the output at pin 7.

Itsu wrote that he is not driving the Q3 from pin 7. He is driving it from pin 1.

...it's driven by pin 1 of the IR2110.

[Itsu]

IR2110 pin 6 is at +15V together with pin 3.

Slight correction; pin 9 is at +12V, not +15V


Itsu

[Vasik041]

Here is updated schematic to avoid further confusion...

[Verpies]

Slight correction; pin 9 is at +12V, not +15V

The datasheet of the IR2110 in the section "Recommended Operating Conditions" recommends, that the pin 9 is between 3V and 20V above ground (Vss) so +12V is fine.  This voltage affects the interpretation of the input logic levels appearing on pins 10 and 12. For example, if you were using 5V logic chips to drive the input pins 10 and 12 then pin 9 should be connected to 5V (the supply rail of these 5V logic chips). Also, the voltage on pin 9 must not be smaller than the voltages on pins 10, 11, 12.  (if it is smaller by more than 300mV then the chip risks damage).

The takeway is that with these conditions, the pin 1 must be at +15V and if it is not, then something is shorting it to ground or the IR2110 chip is bad.

[Itsu]

Thanks for the new diagram.

Concerning the pin 1 being at 0V, when yesterday i had everyting in place (no pulled out chips or pulled up pins), i was monitoring both pins 1 and 7
and both had pulses on them and the kacher was working so i think there is nothing wrong with the IR2110.

But i will redo the pull out U10 and latch up its pins 10, 12 and 13 to find out why i did not had +15V on IR2110 pin 1 later today.


Itsu

[Itsu]

I have replaced R17 with a 8.2KOhm resistor and with U7 (IR2110) removed and its pin 1 wired to +15V, i have 130mA @ 12V running through the collector.

I reinstalled U7 (IR2110), removed U10 and wire its pins 10, 12 and 13 to +12V and still have the 130mA running through the collector.
So now IR2110 pin 10 is 0V, pin 12 is +12V, pin 7 is 0V and pin 1 is +13.3V activating Q3 and thus Q5 etc.

Not sure what happened yesterday during that same last setup but i never had the 12V PS show the 130mA current, nor did i saw +15V on IR2110 pin 1.


Anyway, after reinstalling all the chips etc. and firing up the kacher, the "umph" seems gone now from the kacher as the 12V PS for the primary coil shows no current and a NE-2 neon does not light up.
The scope probe near by does show some minimal activity (typical switched kacher ringing signal).

I now probably need more voltage (100V) on the collector to get the "umph" back.

Itsu   

[Verpies]

So now IR2110 pin 10 is 0V, pin 12 is +12V, pin 7 is 0V and pin 1 is +13.3V

I hate to nitpick but if pin1 really is 1.7V below pin3 (+15V) then this is too much of a voltage drop according to the datasheet when the lowside driver is on.
How much current is flowing out of pin1 ?

[Itsu]

Actually its 15V versus 13.6V, so 1.4V below.   
So what is causing this voltage drop?

Itsu

[Verpies]

I reinstalled U7 (IR2110), removed U10 and wire its pins 10, 12 and 13 to +12V...

Are you sure this is not a typo?
Pin13 is the V_SS, which is the logic ground and should be at 0V.
Pins 2,5,11 should be grounded, too.

[Itsu]

I was talking about U10 (4093).

[Itsu]

Hmmmm,   i removed U10 again and pulled up its 10, 12 and 13 to +12V, and we have +12V on IR2110 pin 12, but nothing on pin 1 (nor pin 7).
Also no current pulled from the 12V PS, so same situation as yesterday, so something is not right.

Itsu

[Verpies]

I was talking about U10 (4093).

OK, that changes things, so the entire t_c point is at +12V and this means that the IR2001.12 should be at +12V and the IR2110.10 should be near 0V.

I removed U10 again and pulled up its 10, 12 and 13 to +12V, and we have +12V on IR2110 pin 12, but nothing on pin 1 (nor pin 7).

So what are the voltages on other IR2110 pins ?
Especially on IR2110.11 ?

[Itsu]

OK, that changes things, so the entire t_c point is at +12V and this means that the IR2001.12 should be at +12V and the IR2110.10 should be near 0V.

Correct.

So what are the voltages on other IR2110 pins ?
Especially on IR2110.11 ?

IR2110.11  is 0V,    see short video of all the pin's measured:   https://youtu.be/4e_ldFBP9BI


Pins measured:

1=0V
2=0V
3=15.06V
4=0V
5=0V
6=15.06V
7=0V
8=0V
9=12.1V
10=0V
11=0V
12=12.1V
13=0V
14=0V

Itsu

[Itsu]

Ok,  i fiddled around with pin 1 of the IR2110 and suddenly there is 13.75V on it, so there is a defective pin1 (chip) i guess  (can't get it to fail now  ), but i will replace the IR2110.

Itsu

[Vasik041]

Ok,  i fiddled around with pin 1 of the IR2110 and suddenly there is 13.75V on it, so there is a defective pin1 (chip) i guess  (can't get it to fail now  ), but i will replace the IR2110.

It could be that when power supply was damaged, it killed something on PCB.
I would suggest carefully check that everything works as expected.

Vasik

[Verpies]

IR2110.11  is 0V,    see short video of all the pin's measured:   https://youtu.be/4e_ldFBP9BI

With the voltages you measured, pin 1 should be close to +15V because this pin is driven by an internal MOSFET (circled in red), which has only several mOhms of internal resistance.
I was suspecting pin 11 to be floating or pin 1 to be shorted to ground ...or being pulled down so hard that the internal MOSFET's voltage drop manifests itself across its R_{DS_ON}.
Another reason for the malfunction could be the UV Lockout due to improper power up sequence.  There should not be an UVL above +10V on pins 3 & 6, though.

It could be that when power supply was damaged, it killed something on PCB.
I would suggest carefully check that everything works as expected.

Yes, I suggest pulling out the IR2110 and using an ohmmeter to do sanity check when the circuit is NOT powered.
Maybe its IC socket has a short between pins 1 and 2 ...or the PCB.

The MOSFET inside the IR2100 (circled in red) really should pull the pin 1 up to whatever voltage is on pin 3, unless a large current is drawn from pin 1 and a significant voltage drop occurs across the R_{DS_ON} of the internal MOSFET.

[Itsu]

I cannot find anything obvious wrong now.

Below screenshot shows the pin 1 (red) signal compared to the pin 3 (yellow) signal (IR2110).

So 15V v 13.8V, so we loose 1.2V.

We have a voltage drop of 23mV across the 6.8 Ohm resistor (R11) to gate of Q3, so 3.3mA running there.

Itsu

[Vasik041]

Earlier we discussed fish-like signals, and there were doubts that they are real.
I'he been looking for good scope traces...here they are, made with analog and digital scopes.

source: https://realstrannik.com/forum/ustanovka-kulabukhova/1327-ustanovka-za-5000-evro-sergej-panov?start=80#102194
https://realstrannik.com/forum/ustanovka-kulabukhova/1327-ustanovka-za-5000-evro-sergej-panov?start=160#102391