Power cut timer for rc cars

[DanB4]

Can anyone help out?

I need to control how long the user is driving the car, 5, 10, 15, 20 mins etc.

My idea is an in-line device between esc and battery connectors which will break the circuit after the selected preset time.

Can anyone help? May be some money in it too.

Cheers,

Dan

[knighthawk]

Not really an answer,
But I take it this is for a show, arrive and drive, pay a couple quid and get a minute or two !!

The only issue is safety !!
Cutting the power to the car, mid flow, will cause the car to role on uncontrolled and may cause a crash or accident !!

The easiest way is to use a small charge is the battery and let the BEC cut in, this way, normally the steering still works to bring it to a stop safely !!

But I'm no electronics expert ( obviously ) LOL

[DanB4]

Yes its to control paying customers time on track.

Safety won't be a problem we're using slow brushed rtr cars with nimh cells and the epa on the throttle at 50%.

[DanB4]

Also the cars have protection and the barriers have angles on so they'll just ride up the barrier.

Saying that, a remote stop would be very cool so someone off track could choose where and when to cut power.

[DCM]

The big issue you have here is the power. The timer circuit would probably be easy to do, but it would have to cut power through a relay or similar, due to it being a power circuit. The cheapest way is a stopwatch and blocking the track.

[Jamie.T]

How about a timed circuit breaker that's used for heating swimming pools, sprinklers etc?

Or, on the very old nicad chargers some used to have a mechanical timer knob on the front which you turned to say 30mins, they had a mechanical circuit breaker which could easily handle the current without any relays etc.

[RudolfXC]

The problem with this is that if the power becomes disconnected when the car is at full speed or on a corner, or both, you would have a spectacular accident.

[dev]

From an electronics point of view I'd make it work the same as the Novak smart-stop widgets, but triggered by time, not voltage.

That way it will work on any R/C electronics and doesn't have to switch high currents, you still get steering, but you have either no drive or very limited drive until you disconnect / reconnect the battery.

Could be done with just digital logic, but easier if it was a microcontroller as then you can choose things like with 30 seconds to go the epa drops to 30%, then cuts off completely.

Cost for someone to build that might not be cheap though, unless you have a mate who will do it for you. For a small electronics company it's probably at least a £500 job (1-2 days work) + parts + ~£50 cost per unit, maybe more.

Would probably be ~2 week turn around for cheap china PCB to be made too, depending on what you want the final product to look like, which limits how fast things can happen.

[mark christopher]

you just need somthing to break the signal wire from rx to speedo, you then get power for steering, as long as the device sends a neutral signal to the speedo ( im sure no signal will just give no power, ie neutral), jumper pins could be used to give different times on resrtictor

[F1END]

If you have a timing system (transponders), you could have it so that the power to the motor cuts off after the next completed lap after the 10 mins timer runs out, then have an 'exit' on the track just after the timing loop.

[DanB4]

Thanks everyone for your input and ideas

[KeithA]

Speak to Luke over at Tatooine and just get one of those R2 units installed on the top of every car. They are over 35 years old now so probably a lot cheaper and smaller than they were in 1977. Just check it hasn't got a bad 'motivator' unit or has been stolen and don't by it from a Jawa.

Sorry DDTCM