remote for rc car

Discussion in 'The Projects Forum' started by juve786, Jul 13, 2010.

  1. juve786

    Thread Starter Member

    Jul 13, 2010
    hello there!

    I randomly wantd to play around with my RC car the other day (the car is a few years old - Nikko's jumping car) and dug up the charger and car from amongst all sorts in the shed, but turns out my mum through away the remote :eek:

    I thought itd be fun trying a make a remote for it, and id get to play! - will this be possible? If so ill need to fix the charger too because the light doesnt come on anymore and it seems like the transformer has gone because the circuit seems fine - any way to test this?
    I will also need to be able to find the exact frequency of the car although i wouldnt mind swapping out the reciever with a new transmitter/receiver pair... i have a feeling this might be easier. The car obviously needs to go frwards, backward, left and right but also a push button that lets the car jump. currently it has a sticker marked at 40MHz.

    Please help
    Thanks a bunch!
  2. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    Good luck.

    Yes it can be done. BUT you to know what the receiver requires in the way of signals to control the servos. They will probably be PWM to the servos. From memory the 40Mhz RC remotes were FM which means it shouldn't be too difficult to replicate.

    Personally I would be going for the new TX/RX idea.
  3. bertus


    Apr 5, 2008
  4. retched

    AAC Fanatic!

    Dec 5, 2009
    You may even consider getting a $5 RC car and "transplanting" the tx/rx parts.

    If you can get the controller to talk to the servos, your in.

    And you would have the original to study prior to surgery. ;)
  5. trader007

    Active Member

    Feb 27, 2010
    and i would bet the charger doesnt come on anymore because the batteries have self terminated by now...
  6. juve786

    Thread Starter Member

    Jul 13, 2010
    (in bed so only going to reply to the last post atm)

    the battery seems to be working fine as it has a teeny bit of voltage across it. last night i took apart the charger and found the primary coil of the transformer is broken. i cut through the red tape to find a little white box with 125*C written on it, and one of its legs werent connected, either side?? - checking with my handy continuity tester, i found that this is where the problem was so i just need to find the ratio of the transformer. problem is all i have handy is the input and output voltageS of the charger with their respwctive currents. can i use this with the turns, voltage and current ratio formulae?
  7. juve786

    Thread Starter Member

    Jul 13, 2010
    hi guys. Ive opened up the car, and another car and its remote (also at 40mhz)
    I see the chips but am confused with the remote of the 2nd car. it has a crystal :S will i have to mess around with the coil in the car to match the frequency?
    and also is swapping as easy as simply replacing the receiver chips?

    another thing - the car i want to make the remote for has a sticker saying 40mhz 4_05. is the 4_05 relevant for anything?