Ni-cd Battery charger

Discussion in 'The Projects Forum' started by MMH, Mar 14, 2013.

  1. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Hello there everybody!!

    I saw a circuit that used 555 timer to charge a 9v Nicd cell. What are the changes I have to make if I want to charge a 2.4v battery?? Or is it fake-for 555 timer is a timer/switch not a charger.
     
    Last edited: Mar 19, 2013
  2. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    It does not seem to work............
     
  3. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Alright, I will now make it and test it myself.
     
  4. DickCappels

    Moderator

    Aug 21, 2008
    2,651
    632
    There are no component values on the schematic. You would have to change the voltage at pin 2. It might be that the pot, P2, has enough range already.

    It sounds like you are thinking of charging two NiMH cells in series. Be careful not to over-charge them. You might want to read up on how to change an NiMH cell before trying to do so.

    http://www.powerstream.com/NiMH.htm
     
  5. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    The value of the components are as follows:
    P1 = 50K
    P2 = 50K
    R1 = 820R
    R2 = 820R
    R3 = 1K
    R4 = 10K
    R5 = 10K
    R6 = 100R
    D1 = 4.7V Zener
    D2 = 1N4001
    D4 = 1N4148
    D5 = B40C1500 Diode Bridge
    C1 = 220uF - 25V
    Q1 = BC547B
    IC = 555
    B1 = 9V Ni-Cad Battery
     
  6. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    so, is it possible........
     
  7. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    so whats the answer??
     
  8. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    I would have used some of the commercial charger chips. As those take better care of your battery.
     
  9. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Thanks!!!!

    OK, I have some problem but I cant start a new tread. My thread was this:

    "Hello there everyone!!!

    I was thinking of making a FM(or AM) radio receiver. I want it to be tune-able. However, I have nothing(at the moment) apart from a 2N2222 and a BC108. Can any of these help to make the radio receiver?? I dont want it to be so much loud(only so that I can listen to it using earphones). I dont have any op-amp at the moment. Is that after-all possible with only transistors, variable cap, a coil of wire and some resistors and diodes??

    Thanks in advance for your assistance."
     
  10. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,980
    744
    Last edited: May 6, 2013
  11. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    I'm writing it here cause I'm unable to start a new thread.

    I have an old MP4(JXD) that I want to fix now. I have done everything except the power supply. Instead of Li-Po that was inside it, I want to use disposable batteries. It had 1 3.6v so I'm planning to connect 3-1.5v in series. I tried brand new zinc-carbons but it failed to keep it on for more than 37 seconds literally! I had to plug it into the charger for half a second and then it worked for another 10 seconds. Is it the problem of my MP4 or the batteries? The battery holders are also kinda rusted. Is there anyone out there who can help me out? I thank you for at least reading it.
     
  12. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Hey, it works for quite a long time if I connect 4 batts in series. I did not see how long but it played 3 songs without problems.
     
  13. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    However, another problem has arrived!!

    After listening to half a song today, I noticed the joint of the power supply wires to the circuit board really hot. Is this because I have used wood wax and not solder to solder them? I cant get a soldering iron at hand. My father will never let me go out and cant expect him to buy it. Anyways, my parents dont know about it. Is wood-wax some kind if poor conductor? If it is, then it must be shorted. Can you tell me a way to stick wires on breadboard without a soldering iron. Sorry, I cant buy one:(:(
     
  14. wayneh

    Expert

    Sep 9, 2010
    12,103
    3,038
    I'm not recommending it as a solution, but there is such a thing as conductive glue. Figuring out how to get access to a soldering iron would be a better strategy. There are also wire wrap techniques you might look into.
     
  15. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Thank you very much for answering!!!

    That's what I need-a conductive glue. I will definitely try to get a soldering iron from a friend secretly, but this shall be a backup I believe. I was wondering for quite a long if any glue can conduct electricity. Now if the conducting glue really exists, then I have a hope:):)
     
  16. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    But no stores have the conductive glue.

    I have fixed the problem but another has arrived!!

    An IC gets hot! The heat travels along the circuit board and warms the wax which makes it expand and disconnects the wires. I think I shall use a heat sink. But I dont have one:p:p

    If I stick a thick long piece of aluminium foil on the IC, will the heat pass through the foil instead if the PCB?? The foil piece will be around 5 times longer than the IC.
     
  17. wayneh

    Expert

    Sep 9, 2010
    12,103
    3,038
    You should start a new thread and show where you are now with the schematic and a picture of your build. It's too hard to speculate without details. A music player should not be getting hot.
     
  18. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Sorry, I cant start a new thread. It says- Server error, and that it might be down for maintenance. I will post picture as soon as I can. Thanks.
     
  19. MMH

    Thread Starter Member

    Feb 8, 2013
    143
    4
    Oh, forget it.
     
  20. Shagas

    Active Member

    May 13, 2013
    802
    74
    Try using a shorter title. Happens to me sometimes
     
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