German schematic conventions?

[steve_rb]

I am having trouble understanding symbols and conventions used in the attached German schematics of a KV generator driver. I want to know their meanings. At pin 6 of X570 there should be about 13 V but I have 3.9 V. I have to the faulty parts and repair. Please comment if you have any advice in this regard too.

1- X15, X10, X16, X17, ... there is a 1 written beside them (see sheet 1 circled in red). What does this mean? Are these means connector X pin1 for example? Then why all of them have 1?
2- 1M, 2M, 3M, ... could be found in P1, P2, P3 .are these ground? if not seems there is no ground.
3-2P24V ? I know P24V means +24V but 2P24V I don't know why? (see browned circled in sheet 3)
4- ICs are denoted N1, N2, N3,... .For example N1 07, N1 4051, N5 324, N2 07, N4 4051,... What does these means?
5- P1, P2, P3, ... all with a 1 beside them (see browned circled). What does these means?

thx

 

[KlausST]

Hi,

I saw the schematic and immediately thought " this is a SIEMENS industrial schematic from the 1970s".
Now I saw it's from the 1990s.

I think the symbols are more "SIEMENS style" than "German style". But are outdated now, hopefully.
I work a lot with such old circuits, because SIEMENS stopped support... and some big industrial plants need repair/replacemen parts/ or improved modern replacement.

*******

Are these means connector X pin1 for example? Then why all of them have 1?

Yes, it's the pin name. But not all of them have just one pin.
--> Blatt 3 (page 3) X570, X2 for example

2- 1M, 2M, 3M, ... could be found in P1, P2, P3 .are these ground? if not seems there is no ground.

1M... is GROUND.
"M" is the abbreviation for the (mature) German word "Masse" = GND.

Btw: on page 1 right sude there is a hand written translation of "Masse Sternförmig".
--> Translate it with "star connected GND".

****
P1, P2 most likely are testpoints (maybe: German "Prüfpunkt")

****
2P24V: I'm not sure
* either there are several independet 24V power supplies denoted with 1P24V, 2P24V
* or there is one 24V power supply with several 24V connections (non isolated). I think this is more likely.

****

For example N1 07, N1 4051, N5 324, N2 07, N4 4051,

N1, N2, N3 ---> should be IC1, IC2, IC3 ... just the name
The next lines are assumptions
07 --> OP07 (precision Opamp)
4051 --> CD4051 (CMOS analog MUX)
324 --> LM324 (quad standard Opamp) note: you see several N5 324, because there are 4 Opamps in one package
785 --> TCA785 (phase control IC)

And the big one in bottom of page 1 is a "high power dual SCR"

Klaus

- - - Updated - - -

Added:

At pin 6 of X570 there should be about 13 V but I have 3.9 V.

3.9V makes sense.
13V not - at least not in a closed loop.
At first sight it seems the Opamp output is in positive saturation...but V28 should prevent the voltage to go beyond 8.2V.

There are a lot of possible causes. Please use a high ohmic DVM and measure all 8 pins of the Opamp w.r.t. GND and tell us the values.

Btw: The Opamp circuit is part of a PI or PID regulation loop. With the MUX and it's control pins x570 - 15, 16, 17 one can digitally adjust the regulation characteristic.

(Without closed loop it surely will saturate, because of it's "integral behaviour".

Klaus

 

[steve_rb]

Well done. Great explanation.
Regarding pin 6 of X570, according to Siemens documents voltage at this pin should always show about 13 V. This is out of question. I have to find what is wrong it is 3.9 V now and fix it. Attached is a brief schematic of the two X570 and X522 connectors showing pin 6 of both are connected. Also showing overall schematic of their connections inside their respective boards. V28 as you mentioned can provides 8.2 V but it is possible that some current to be flowing through R79 and R93 due to SIG6 which can provide extra voltage to add up with 8.2. Right?

 

[Akanimo]

Hi,

/2C7 for instance means "connected to page 2, row C, column 7"

- - - Updated - - -

X1, X2,...Xn seems to me to be test points.

 

[steve_rb]

Thank you. Very good points.
The whole device is a power supply for a X-ray tube. In fact it is a X-ray generator. Complete connection of X570 to X522 is attached along with X530 connector pins values in heating and normal use mode. In heating mode only x-ray tube filament is hot due to 1.9 Amp current going though it but at normal use this current goes up and also high voltage (about 40 Kv) is establish between filament and anode. Heating mode working OK but when I turn operating mode device is trying to establish high voltage but oveshoot happens and gives me error code =3 (showing: "kV actual value >110% of set point"). X530 is just a test connector for connecting test adapter for diag purposes.

One other thing I don't understand is pin 19 of X530 (=pin 19 of X570). This pins has 2.0792 V ref but at X530 it says it is 0 V (GND) in both heating and normal use modes and in page 1 it goes to "star connected GND", separated with dash lines . How this could be explained?

 

[steve_rb]

I have attached a brief explanation of how the whole device works.

Please use a high ohmic DVM and measure all 8 pins of the Opamp w.r.t. GND and tell us the values.

Board is located in a hard to reach place but I will try to build an extension to be able to take it out and do on board measurements and tests.

 

[Akanimo]

X-ray generator? That's a high-class hazard.

You need a lot of care working on it so you don't get X-ray all over you.

I think at this point, you have to pause and reassess the hazard and then go ahead with the repairs only if you are satisfied with the conditions you find yourself.

 

[steve_rb]

Don't worry about that. When instrument error gets away instrument will be passed to x-ray people to proceed. For me there is no tube inside so I wouldn't worry about this.

 

[steve_rb]

@KlausST

3.9V makes sense.
13V not - at least not in a closed loop.

Yes you were right. 3.9 V for pin 6 is confirmed by Siemens. It seems I was reporting from a wrong document.

Back to the schematics I need to know meaning of the followings used inside schematics:

1- -REGL.
2-I.NETZ
3-ST.BETR.
4-TEST GRUNDWERT
5-IMPULSSPERRE
6-co. 300ms
BEIM EINSCHALTEN
HOCHOHMIG

Bridge X3-X4 supposed to change the device output to a minimum level but has no effect. It seems if I keep tracking from this point I may be able to get into the bottom of this problem.

X3,X4,X5 and X6 are high lighted in the board layout. It seems these points are critical test points. Monitoring signal at these point (specially x5 and x6) should give some great clue. Board is located in a hard to reach place and difficult to do any measurements but x points all has a pin for connecting test probe. Thanks to Siemens engineers for this.

Any advice?

thx

 

[Akanimo]

Hi,

REGL means regulator.