[Hy-Speed]

I'm wondering if I can reduce the voltage on a 4 car pb using a variable psu? This is to limit the speed for kids on a club practice track. Thanks in advance for any replies.

 

[MrFlippant]

I believe you can, but not as far down as you may need to go for the cars to stay on at full throttle. The 4 car base will go into a brown out mode if the voltage goes much lower than the expected input. I don't know what that level it, though. If anyone knows, RichG or RikoRocket would.

 

[RikoRocket]

I've run one successfully on a C7004 (12V), so down 4 Volts

 

[Hy-Speed]

Did taking the power down by 4 volts slow down the cars significantly?

 

[RikoRocket]

Yes, running with magnets they were slow, real slow.

 

[Ade]

hi
a cheap variable voltage psu might be the best option,or cheaper still a fixed one with a output of 13.8v something around the 4_5 amps region.

 

[MrFlippant]

WOW! 4 volts?!? Wow. I figured it would brown out before that. Is that dependent on the version of the base, or will any old/new 4 car base handle volts that low?
That's super good to know, actually. It makes a variable voltage PSU even more useful, even (and especially) for beginners.

 

[RikoRocket]

We are talking 12Volts, (4 Volts down on the standard 16V) even on the C7030 you could get down to below 11V before the brownout would cut in... Actually I think I shorted out one of the diodes so that would be + 0.7V so actually only down 3.3V.

 

[MrFlippant]

Ah, ok. I totally mis-read that.

My bad.
12v volts makes a lot more sense. I guess it depends on the layout and the cars, then.
In any case, 12v would be better than 15v for helping new drivers stay on.

 

[Ade]

hi
i managed to get my old pbpro +sh down to 10.4v for racing F1 cars.(measured at the rails with a cheap multimeter)

 

[RikoRocket]

Hy-speed, if your club is going to have a C702 then you can set lower power levels to make kid friendly racing

 

[Hy-Speed]

Thanks for all the replies. The idea was that we have two tracks, one using a c7042 (which we have done - see www.hy-speed.co.uk) and the other as a practice track for the kids using a spare 4 car pb. We wanted to take the power down so we didn't have the club cars flying into the walls! However, we've decided not to do this at the moment due to organisational issues.

 

[300SLR]

Another option is leave the power supply alone and fit a stop to the controller so the trigger cannot be pressed all the way down.
That way the cars are slowed down but there are still plenty of volts to drive the electronics and the lane changers.

 

[RikoRocket]

Or add a small resistor in parallel so it never gets to 3F

 

[Hy-Speed]

What does 3F mean?

 

[RikoRocket]

3F is the hexadecimal value that the computer chip inside the 4PB reads when the throttle is fully pulled. Except for a lot of the ealy ones it didnt get anywhere near. Adding a resistor in parallel to the main slider would reduce the max value (throttles go from zero trigger=zero ohms to max trigger=max ohms) so it would reduce top speed.