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    [SOLVED]Closed: Re: USB to RS232 exactly similar to COM1

    Yes I got the pin number wrong. Now it is OK and device working OK. Thank you all.
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    [SOLVED]Closed: Re: USB to RS232 exactly similar to COM1

    Problem is almost solved but not quite. I have a USB-to-TTl converter and it gives me +5 volt at pin 2 and 3 with respect to pin 5. I have added a MAX3232 rs232-TTL converter and now I am having -9 v...
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    [SOLVED]Closed: Re: USB to RS232 exactly similar to COM1

    Device works with COM1 of my desktop computer and also with COM1 of my old heavy laptop. This means it comply with RS232. As far as I know COM1 is RS232. I checked voltages of pin 3 with respect to...
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    [SOLVED]Closed: USB to RS232 exactly similar to COM1

    Hi All,

    I have purchased a few USB to RS232 converter but non of them couldn't give me exact COM port of a desktop PC. In my desktop PC running windows xp voltage of pin 3 of COM1 with respect to...
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    Closed: ISO 6141, 6142 and 6143 ?

    Anyone has these ISO files for mixed gas analysis? Our detector uses mixed gas and I need to know about ISO standards for repairing electronic boards of the detector.

    thx
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    Closed: Replacement for AD848JR

    I can't find AD848JR (SMD) in local market. It has been used in a pre-amplifier circuit and since it is burned I need to replace it. Any suggestion for replacement?

    thx
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    Closed: Re: OP07 circuit output voltage?

    Simple schematic of the whole system is attached. Voltage of pin3 manually set depending what Kv we want at the end. OP07 output adjust the thyristor fire angle to generate proportional kv at the...
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    Closed: Re: OP07 circuit output voltage?

    [QUOTE=Easy peasy;1658118]point X is not defined anywhere I can see - do you mean the o/p of the OP07 ?


    Yes. At post #1 you can see it. It goes to another board (see attached red circled)
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    Closed: Re: OP07 circuit output voltage?

    I have an idea:

    I want to install a 2.75 zener diode between point X and ground. This way I will force point X to stay at 2.75 v and will have a stable pre-start condition. I will not be able to...
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    Closed: Re: OP07 circuit output voltage?

    Nice explanation but honestly with my poor electronic knowledge I should say I didn't get much what to do. Could you please put it in a stepwise procedure what should I do to get close to the...
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    Closed: Re: OP07 circuit output voltage?

    I have attached the whole U-regulator circuit if it can help

    - - - Updated - - -

    I have attached the whole U-regulator circuit if it can help
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    Closed: Re: OP07 circuit output voltage?

    I am also thinking so but the stupid Siemens document says output should be 2.75 v and this puzzled me too. I am not very good with circuits. Probably parts around the OP07 somehow should decrease...
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    Closed: Re: OP07 circuit output voltage?

    umsch1 and umsch2 are not relevant in this stage so forget these.
    Adjustments mentioned in post #6 also is not relevant in this standby stage.
    Component are OK.
    Haven't done simulation. I am not...
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    Closed: Re: OP07 circuit output voltage?

    With precise look at the documents it shows pin 2 voltage should be 0.0 and pin 3 voltage should be 0.1 v which is almost the same voltages I have measured. Also document shows with these inputs...
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    Closed: Re: OP07 circuit output voltage?

    @ FvM

    You are right. I haven't include the whole circuit because close loop control has not started yet at this stage. There is an "On" button (not presented here) which by pushing it R1 and R2...
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    Closed: Re: OP07 circuit output voltage?

    2.75 is starting point. When circuit starts this voltage is supposed to be stabilized at 2.75 automatically. Then manually condition could be adjusted. input at R1 is the set value for the manual...
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    Closed: Re: OP07 circuit output voltage?

    At the moment I am getting 14 V. It should be 2.75 V according to the circuit documents. As you can see voltage at the R2 and R3 inputs are about zero. There is something wrong which causing this 14...
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    Closed: OP07 circuit output voltage?

    Hello All,

    I need to know what voltage I should expect at output point X if both inputs were close to zero in the attached circuit?

    Also please comment about the gain of the OP07 and the...
  19. Closed: Re: 13.9 V instead of 2.75 v, Which parts are failing?

    I checked V403 and V402 diodes on board and they are OK (0.7 forward and 1 revers selecting ohmmeter diode test). Also I checked R419, R405 and R420 resistors on board and all have correct...
  20. Closed: Re: 13.9 V instead of 2.75 v, Which parts are failing?

    Both N403 and N2 are OP07 operational amplifiers. I don't have better quality schematic. Red line shows connection of the X522 pin 8 to X570 pin 8 of another board. Pin 8 of X522 carrying a...
  21. Closed: 13.9 V instead of 2.75 v, Which parts are failing?

    Hello,

    I am having trouble finding which parts are bad and causing I am getting 13.9 Volts instead of 2.75 Volts with pin 8 of X530 connector (red question mark)?
    X530 pin 8 is only for test and...
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    Closed: Re: German schematic conventions?

    @KlausST



    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...
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    Closed: Re: German schematic conventions?

    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.
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    Closed: Re: German schematic conventions?

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




    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...
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    Closed: Re: German schematic conventions?

    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...
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