is this a half wave rectifier?

Discussion in 'General Electronics Chat' started by kirayamato_143, Sep 21, 2011.

  1. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    i want to know if d1 is a half wave rectifier cause I'm thinking to connect it directly to my power supply with 12v and 9v output directly to BR2 the full wave rectifier taking d1 out of the schematic,,i attached the photos
     
  2. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    i just wanna ask now how to simulate a battery charger in proteus,,please help me i dont know..
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Yes, D1 is a half-wave rectifier. It appears offhand that the circuit is a lead-acid battery charger.

    I don't know what you're talking about with the 2nd part; that isn't a power supply, it's an audio amplifier.

    A 12v lead-acid battery would need a higher input voltage to charge it.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Why don't you put that 1st circuit you attached in Proteus?

    Instead of a battery, use a large capacitor to simulate a battery, with a 10m Ohm resistor in series with the cap, and a 10k resistor in parallel. It would be good to start the battery off with an 11.4v charge, which would be a 100% discharged battery.

    There is a somewhat similar battery charger in the Completed Projects Collection forum. Have a look at this thread:
    http://forum.allaboutcircuits.com/showthread.php?t=6099

    You can use many other opamps than the one shown, as long as it's better than a 741.
     
  5. radiohead

    Active Member

    May 28, 2009
    474
    31
    The 2nd circuit isn't an amplifier, it's a crossover. There are pass filters there for the woofer, midrange and tweeter.
     
  6. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    sorry i uploaded the wrong schematic,, i changed my schematic and now i want to ask if this schematic automatically turns off when the battery is full charge,,http://www.circuitdiagram.org/automatic-nimh-battery-charger-circuit.html
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    No, the charger does not turn off.
    The LED doesn't work properly, either.
     
  8. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    why is that so? but the site say it turns off the led when full charge i just dont know if it cease to charge also after full charge,, i really have to start reading to lessen my questions,,sorry,,but please bear with me,,i'm new in electronics
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    There are LOTS of schematics floating around the Internet that people never simulated, let alone build and got working. I have seen many really bad circuits out there. I have made a few poor ones myself. :rolleyes:

    The LED will turn on when charging starts, but as charging progresses, the LED will slowly dim and turn off. Exactly WHEN that happens depends upon the Vf of the LED and the charge on the battery, which is really not the way to do things.

    The charge current remains constant for awhile, then starts dropping as the regulator output voltage gets within several volts of the input voltage. The output termination voltage is entirely dependent upon the unregulated input voltage. It actually does terminate the charge, but at a voltage that you have no control over, and it does not monitor the battery temperature which is critical for a NiMH battery. Unless you monitor the temp and look for the "bump", you won't be able to really tell when the charge current should be turned off.
     
  10. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    thanks,, yeah thats really a problem i dont master my proteus and so need to trust schematics from the internet,,sorry to ask for a solution to my problem but its something least i can do,, can you point me to an easy and working schematic for 9v nimh charger that automatically turns off upon full charge and recharge the battery again if needed without human intervention? sorry to ask like spoonfeed
     
  11. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I don't have one for a NiMH. You really need to monitor the temperature along with the voltage. That requires either a dedicated charger IC with supporting components, or to program a microcontroller with supporting components.

    You also have to follow the battery manufacturer's recommendations for charging.

    Don't use a NiCD charger for a NiMH, as they are different technologies.
     
  12. kirayamato_143

    Thread Starter Member

    Jan 23, 2011
    59
    0
    now it sounds too complicated,, geez i hope somebody will post a simple and working nimh charger,,, thanks for the reply its nice to know..
     
Loading...