Golf Cart Radio looses clock

Discussion in 'General Electronics Chat' started by Best2bgolfing, Apr 28, 2014.

  1. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    I have a golf cart which has a Radio/ CD player. Every time I go to accelerate the starter draws current and the radio blanks out. I have looked a circuit wiring and loss of voltage but all are in good order. When the starter/generator cranks the motor the voltage at the radio go down to 8.5 volts. I was thinking to install a capacitor to stop this from happening. Not exactly sure how to wire the capacitor into the circuit. I purchase a capacitor 4700uF. Do I also need a diode on the circuit. Please advise or supply another fix.

    Thanks,
    Tom
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Your capacitor will be drained at the same time, for that capacity, especially.
    Max.
     
  3. wayneh

    Expert

    Sep 9, 2010
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    First I'd try a fresh battery, and make sure the starting system is not loaded down somehow. The voltage shouldn't bog down that far. A car has big problems if the voltage sags to 9V or so - the computer doesn't like that.

    To implement your capacitor idea, more capacity is better. It will take a fairly large capacitor and only testing can answer how large is large. I would put a diode in series with the radio power supply, and the capacitor across the radio power poles, after the diode (closer to the radio).
     
  4. bwilliams60

    Active Member

    Nov 18, 2012
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    What is system voltage on this unit. Is it 9V or 12V? My first thought is that you have a battery problem and perhaps even a charging problem but one thing at a time. Do you have a way to load test the battery? I think the best place to start is always at the source.
     
  5. #12

    Expert

    Nov 30, 2010
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    Like this..
     
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  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Instead of a capacitor you would be better off using a battery there. It will last longer for an extended peel out, and charge along with your main cell too. Do try to match the battery chemistry of the main bank.
     
  7. #12

    Expert

    Nov 30, 2010
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    This isn't as easy as it might seem. A radio can use a LOT more power than a clock, and that would require quite a lot of capacitor, or a battery. Then, you have to try to get the battery to charge correctly with the inherent battery charging system.

    This worked well enough with the old alternators from the 1970's where I could put in 2 diodes and the alternator just powered up enough voltage to charge both batteries correctly. Now, we have "one wire" alternators that can't sense remotely and don't compensate.

    We gave you what we could with what we had to work with, but you better have some skills or it's going to end up just barely working...or worse.
     
  8. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I would consider a cheap (Chinese) boost regulator.
     
  9. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Simple and cheap solution,
    - buy a little adhesive digital clock and stick it to the front of your radio (or anywhere else on your cart).
     
  10. wayneh

    Expert

    Sep 9, 2010
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    Or better yet, remove both the clock and the radio. They're of no use on the golf course.
     
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  11. bwilliams60

    Active Member

    Nov 18, 2012
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    Forgive me if I offend anybody with this post but doesn't the KISS rule apply here. We are talking about fixing something that may not even be a problem. If the radio and the clock worked before, doesn't it make sense to go back to the source and make sure it is delivering what it should and perhaps make sure the motor isn't drawing more than it should? Someone help me. This sounds like we are putting the "cart" before the horse ;)
     
  12. #12

    Expert

    Nov 30, 2010
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    I think wayneh hit that in post #3, "The voltage shouldn't bog down that far".
    The best cure is probably to fix the starting system. Have an adequate battery and clean wiring connections.
     
  13. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    It's very normal for car radios to blank out when starting the engine due to reduction of the 12v supply.

    Many car radios have undervoltage protect circuits to deliberately drop them out when engine starting, to protect their output amp.

    Why is it even a problem? Do you really need to listen to the radio for those few seconds your engine starter motor is going "roopa roopa roopa"?
     
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  14. Metalmann

    Active Member

    Dec 8, 2012
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    I bet the OP's is a 48 Volt, electric cart.:confused:
    Not sure how that system is wired.....

    He didn't mention if it's a gas or electric cart.

    My gas Club Car, is similar to an auto engine charging system, using a 12 volt battery.
     
  15. alfacliff

    Well-Known Member

    Dec 13, 2013
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    is that voltage drop for the radio measured at the radio or battery? if at the radio, test the voltage across the battery when starting, it might be the radio needs to be connected dirrect to the battery (at least the clock).
    also, most radios with clocks have two power leads, one for the radio and one for the clock. a diode in series with the clock power and a fairly large electrolytic might hold the clock up while starting.
     
  16. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    Thanks, I am not sure what you are suggesting. I understand it as install a 16v (my estimate) rechargeable battery bank and have it paralleled in the circuit. With a diode before the supply. This will keep the battery bank from supplying the golf cart.
     
  17. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    The cart is a gas cart, 12v just like a car. I have a digital meter and cannot locate the dropping true voltage line. The battery is new and of quite a large capacity.
     
  18. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    The voltage reading I sent is at the radio. I have spent many hours checking all the circuits they are in good shape. I have extensive auto experience and formal training 40 years worth. The golf cart is wired just like a 1970 car. What it is doing is just un explainable. That is why I was thinking a capacitor would help.
     
  19. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    KISS is a good rule I often subscribe to it. But this is a condition from when the Cart was built. All the connections are in good condition and are wired just like all the rest of the carts of its kind. It is a custom golf cart they are called Streetrod Kustom Karts.
     
  20. Best2bgolfing

    Thread Starter New Member

    Apr 28, 2014
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    Thanks for the schematic now I need to get a Diode of proper size.
     
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