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Faulty Charging Circuit

Discussion in 'General Electronics Discussion' started by Christ Kalafatis, Aug 18, 2017.

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  1. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    battery.PNG Dear Sir,
    I want a little help if it's possible.
    I have a Jumpstart of my car and the inside battery have damaged.
    I bought a new 35 euro (12V bat.) and I'm trying to solve a problem.
    It has a board inside connected with the battery to charge it.
    Also there are two LEDs (1 LED-Orange and 1 Green LED.
    When I connect the Pack with 12V the Orange LED is lit and
    battery is charging for a long time without cutting OFF (reaches 16V and go on...)
    (danger to overcharge and destroy the battery).
    Normally when battery is fully charged, Orange LED must go OFF and
    Green LED must go ON for stop charging.
    I designed with a program the circuit of my Jumpstart and send it to you for help.
    The Orange LED is continuously ON and Green LED don't light at all.
    Also it has a Relay 12V DC and is in NC position and doesn't go in NO
    position.
    I think that Relay must go in NO position for the Green LED to be light
    through R2=1,2K and for the battery to stop charging.
    In what component I must search (by your opinion) for the fault and how this
    circuit is working.
    Let's explain to me with a few words if you have no much time.

    Thanks a lot
    Christ
     
  2. Externet

    Externet

    737
    159
    Aug 24, 2009
    To start without going deeper, are the top two pins in the schematic the relay coil ? The relay shows both coil pins bridged together to Vcc. If the coil pins are the central ones, they are also bridged.
    If that is the way it is built, it will never energize.

    The title for your post could be more descriptive. Welcome anyway.
     
  3. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Hi friend,
    Sorry, my mistake.
    I send you the diagram of Relay 12V DC (SONGLE SRS 12V DC-SL) and a photo of PCB.
    Thanks a lot.
    Christ
    battery.PNG
    b2.jpg
     
  4. Externet

    Externet

    737
    159
    Aug 24, 2009
    On the schematic, pin 8 of the LM358p is supposed to be its Vcc supply for the IC to work. Has no supply.
    On the picture, appears fine, but pins 5,6,7,8 bridged ?
     
  5. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Pin 8 of IC has Vcc supply 16V6. Pin 7 has no junction. Pin 5,6 bridged (value 16V6) and go to NO of Relay.
    How NO of Relay will be energized for the Orange LED to go OFF and Green LED to go ON and stop charging the battery?
    Maybe must stop conducting TR S9013 for the Relay to change position?
    Thanks
    Christ
     
  6. Externet

    Externet

    737
    159
    Aug 24, 2009
    Correct. For the relay to deenergize, the transistor must stop conducting and for that to happen the output voltage of pin 1 must go to a lower than 0.5V.
    The change of pin 1 from high to low is commanded by comparing the voltages at pins 2 and 3.

    The resistors to the right of the IC create voltages that are sensed by pins 2,3 and the IC triggers its output when voltage surpasses or falls below an adjustable preset value.
     
  7. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear Sir,
    Thank you for your help and I appreciate it very much.
    In pin 2 of IC LM358N I have 5,70V steadily because of zener diode D22.
    I adjust from POT Trim the voltage in pin 3 of IC at 5,85V and in pin 1 output of IC
    I have 10,78V (high) and through R9=82K in base of TR S9013 is conducting and energize the relay and
    the battery 12V, 18Ah of my Car is charging through D18 diode and Orange LED is lit on
    but is continuously ON for hours.
    When battery is full charged then TR S9013 must stop conducting, Relay be deenergized (must go to NO position)
    and Orange LED must go to off position and Green LED must go to ON position to indicate that
    battery stops charging.
    I have a question. I test TR S9013 and Green LED and is OK. Why isn't lit ON while I have low output in pin 1 of IC and TR S9013 stops conducting and why relay doesn't go to NO position after full charging?
    Sorry for my little English but I'm trying to explain and I need your help because I'm a beginner and
    maybe is difficult for me to understand very well your very good help.
    Also how the 2nd IC LM358N is working with the D31 diode and S8050 tranzistor and what is the use
    of them in the circuit?
    Thanks a lot
    Christ
     
  8. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    battery.PNG
    Dear Sir,
    12 days without any help. Please I know that you must answer to a lot of
    questions and I'm waiting with patience. If its possible to have an answer/help.
    Thanks a lot
    Christ
     
  9. kellys_eye

    kellys_eye

    4,276
    1,146
    Jun 25, 2010
    Your schematic is in error.

    In order for charging to stop your first schematic (at the start of this thread) shows the lower LM358 having a 'floating' Vcc connection. I suspect this is meant to be supplied via Q33 S8050 which itself is switched via the comparator (top LM358) which sets the point at which the circuit decides full charge has been reached.

    Simply - the lower LM358 is switched on/off by the measurement (comparison) made by the upper LM358.

    If your charger isn't switching off then the voltages that set the upper LM358 switching point are wrong/missing.
     
  10. shrtrnd

    shrtrnd

    3,734
    478
    Jan 15, 2010
    This may have no bearing on your problem at all, but I'll input an observation:
    I don't know your vehicle/electrical system.
    My experience with trying to jump a car battery that results in damage to the battery, is that in the old cars I've worked on, the diodes in the alternator are often damaged.
    You've got excellent information concerning the circuit board you're working on, from others on this forum.
    On the off-chance that it might have happened, I just wanted to let you know that the current path within your vehicle electrical system may not be what you expect with a damaged alternator in the circuit.
    Good luck with the repair.
     
  11. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear Sir,
    Thank you very much for your help.
    See the last Schematic, not the first because I have made a mistake.
    Also I send you the lower part of circuit PCB in 2 pieces.
    I give 12.6V with an external analogue power supply in the lower red point (left of R7).
    In pin 2 of lower LM358P I have 5,70V steadily because of zener diode D22.
    I adjust from POT Trim the voltage in pin 3 of IC at 5,89V and in pin 1 output of IC
    I have 11,38V (high) and through R9=82K in base of TR S9013 I have 0.692V.
    How many Volts must have in Collector of TR Q19 S9013 for energizing the relay NC to charge (indicating with Orange LED the charging), because Green LED is continouously ON which means that NO position is energized instead of NC.
    How the top LM358P sets the point of full charge via Q33 S8050.
    Please can you explain more in detail how the circuit is working from the upper red point...
    Sorry for my big question but I'm a beginner and need your very good help.
    Thanks a lot
    Christ
     

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  12. kellys_eye

    kellys_eye

    4,276
    1,146
    Jun 25, 2010
    Show pictures of both sides of the board, clear of any wiring and in its entirety.
     
  13. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear kellys_eye,
    I will try to send you both sides of the board, clear of any wiring and in its entirety.
    Can you please explain to me from my design how is comparison taking place with the top LM358P
    and other components in relation with upper red point and how I must adjust the full charge point
    in order to stop charging and Green LED go to ON position.
    Thanks a lot
    Christ battery.PNG
     
  14. kellys_eye

    kellys_eye

    4,276
    1,146
    Jun 25, 2010
    I don't trust your schematic.

    This is why the pcb layout is necessary.
     
  15. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear kellys_eye,
    I know but I'm not a good technician and I try.
    It's difficult for you without the whole pcb. Let's try to help me.
    Thanks
    Christ
     

    Attached Files:

  16. kellys_eye

    kellys_eye

    4,276
    1,146
    Jun 25, 2010
    First picture lacks focus. The other two have someone's hand in the way.......
     
  17. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear kellys_eye hi,
    I tried and I think this time is a little better.
    Left of black wires (GND) there is nothing. In front of them is TR Q19 S9013.
    Sorry for the trouble.
    I appreciate very much your effort to help me.
    Thanks a lot
    Christ
     

    Attached Files:

  18. Christ Kalafatis

    Christ Kalafatis

    10
    0
    Aug 18, 2017
    Dear kellys_eye hi,
    1 month about without any help. Please I know that you must answer to a lot of
    questions and I'm waiting with patience. If its possible to have an answer/help.
    Thanks a lot
    Christ
     
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