12v to power a Scalextic in a field

[ban-all-sheds]

You will need people to replace cars on the track.

A friend of mine was at a trade show once where one of the stands had a Scalextric competition to increase footfall.

It was hugely popular, crowds there all the time.

Possibly because the people replacing cars had tight low-cut t-shirts and very short skirts, and could only reach parts of the circuit by leaning over.

That may not have been much help to the OP.


This might be:

I don't know how many lanes the track has, nor what competition formats you plan, but there used to be a famous toy shop in London called Gamages, and every Christmas they ran a "beat the house" Scalextric competition, i.e. they had a car running round on its own which you had to beat to win the prize - the top of the range Scalextric set.

Very difficult - basically the house car was on full throttle all the time, and they put sellotape on the track at strategic places to cut the power. Then they just cut it away, little bit by little bit, until they had the car going as fast as possible.

 

[Jack155Q4]

You will need people to replace cars on the track.

A friend of mine was at a trade show once where one of the stands had a Scalextric competition to increase footfall.

It was hugely popular, crowds there all the time.

Possibly because the people replacing cars had tight low-cut t-shirts and very short skirts, and could only reach parts of the circuit by leaning over.

That may not have been much help to the OP.

I will ask wifey.....don't think I will be too popular in doing so though!

This might be:

I don't know how many lanes the track has, nor what competition formats you plan, but there used to be a famous toy shop in London called Gamages, and every Christmas they ran a "beat the house" Scalextric competition, i.e. they had a car running round on its own which you had to beat to win the prize - the top of the range Scalextric set.

Very difficult - basically the house car was on full throttle all the time, and they put sellotape on the track at strategic places to cut the power. Then they just cut it away, little bit by little bit, until they had the car going as fast as possible.

Love that idea. It is a two lane track. I will see what I can come up with. Will be tricky to do so as you say but a bit of black insulation or sellotape would do the trick. Would be good to mix it up with a couple of crossovers and lane narrowers!

Cheers.

 

[ban-all-sheds]

Sellotape is good - people can't see it.

 

[Jack155Q4]

what type of cars are you running, my understanding is the older "analog" cars had speed controlled through the voltage going to the track, this would have a larger voltage drop issue as you could only feed power from one point.
If you have the newer "digital" cars, the speed is controlled in the car, so you can do as James May did and have power connected at various points around the track.

They will most likely be the old analogue type.
I am going to have to feed the circuit in a few places - I am think parallel connections from the main entry point across the circuit to the furthest point.

On the digital stuff the controller is assigned to the car but you still 12v round the track in all places.

What I know about this is little as you may be able to tell.

 

[Jack155Q4]

ok you will probably get great results from a car battery on a boost charge [plus 20%=14.4v]as opposed to trickle charge [12.8 to 13.5v ish]

if you have a slow down mid cuircut add further power wires to that point to get less power loss more speed

The cars and controllers are speced at 12v - If I am charging a 12v battery at 14.4v will I not have 14.v going in to the track or does it not work like that?

 

[Jack155Q4]

Running any sort of competition was impossible. Without a cross over the outer track was longer that the inner one which meant the driver on the inner track had an advantage. It was run as pay your money and do so many laps and then next customer. That was the faster turn round for customers and the quickest way to get cash from them.

That is the plan with a digital lap timer to avoid disputes...

The track was in direct sun light and got hot enough to deform. This meant the electrical connections between sections failed. I had several feed points spread around the track which saved the day. You will need people to replace cars on the track. If you have optical sensors for detecting cars and counting laps then be aware they may not work in bright sun light. Mine didn't

I will be in a marquee out of direct sunlight so I hope this is not an issue but it is noted!

I will have gas powered soldering iron on hand for emergency repairs!

 

[Jack155Q4]

Is there a basic calculation to determine how long a car battery would last if I can find out the power consumption of the scalextric cars at full pelt.

I guess I would need to know how long is could sustain 12v at about 1 or two amps.

If a car battery has 45 amp hours does that mean it will provide 12v at 1 amp for 45 hours? I doubt it but if I don't ask I won't know!

Avoiding the use of a generator would be very beneficial.

 

[timtheenchanter]

theoretically yes, but in reality, no.
for these purposes, a leisure or traction battery would be better, they are designed for low load over long periods, car batteries are designed for large current over short time.
also, if this is a competition, later competitors would have a reduced voltage, so the cars would run (slightly) slower, so if you were going for a best time of the day this might be an issue, if, on the other hand you were going against another car head to head, both would have the same issue, so all would be fine.
is there any power available anywhere, if so 2 batteries would be a better idea (on in use, one on charge)
A fully charged car battery is 12.6V (6 cells at 2.1V each) 12.1V is 50% down, and 11.9 essentially dead.
are there any caravan users involved? they may be willing to lend their leisure batteries, some may even have some decent solar panels to keep it topped up in use.

 

[ban-all-sheds]

what type of cars are you running, my understanding is the older "analog" cars had speed controlled through the voltage going to the track, this would have a larger voltage drop issue as you could only feed power from one point.

No - you can have several points of supply. Actually what you have are cables connecting different points of the track together - Scalextric used to do them as accessories - a bit of bell wire with a plug on each end - they just went into the places on the straights designed to have power connected.


On a general note, beware of using battery chargers as they have an unsmoothed full-wave rectified output with an RMS voltage equal to the charging one - the peaks are higher, and I used to find that my motors ran hot, and sounded a little ragged.

 

[Jack155Q4]

theoretically yes, but in reality, no.
for these purposes, a leisure or traction battery would be better, they are designed for low load over long periods, car batteries are designed for large current over short time.
also, if this is a competition, later competitors would have a reduced voltage, so the cars would run (slightly) slower, so if you were going for a best time of the day this might be an issue, if, on the other hand you were going against another car head to head, both would have the same issue, so all would be fine.
is there any power available anywhere, if so 2 batteries would be a better idea (on in use, one on charge)
A fully charged car battery is 12.6V (6 cells at 2.1V each) 12.1V is 50% down, and 11.9 essentially dead.
are there any caravan uses involved? they may be willing to lend their leisure batteries, some may even have some decent solar panels to keep it topped up in use.

Thanks. Blimey....it is a fine line between half dead and dead!

 

[big-all]

basically the way it works is the battery will have high voltage up to 20% over if your motor is rated at 12v 1 amp if you give it 14v it will run faster and draw more than 1 amp as the voltage drops to say 10v the current draw will fall off
if i remember correctly it used to be 0.75 for the old motors and 0.25 amps for the ring field motor so would expect a can motor to be around the 0.5 amp mark

you will probably get away with 2 feeds as your halving the distance and doubling the feed or in effect turning into quarters

the over voltage wont hurt unless you can sustain full speed continuously where in actual fact the average will be nearer 50 to 75% if you include the odd bit off down time

 

[timtheenchanter]

http://www.varta-automotive.com/?id=515&artikelNr=830150090B922&L=0

This has a discharge curve on it, OK its for an AGM battery, but the curve of leisure is similar, basically, up to 50% charge is usable, after this, the curve drops sharply to dead (the way the battery works, and the extra load upon it caused by the lower voltage) so if you get a 110AHr leisure, you have 50ish amps usable.

 

[Jack155Q4]

On a general note, beware of using battery chargers as they have an unsmoothed full-wave rectified output with an RMS voltage equal to the charging one - the peaks are higher, and I used to find that my motors ran hot, and sounded a little ragged.

As these days go...actual track usage time will not amount to too much. Assume each lap is 20 seconds. 5 laps per person with lets say 150 people (over estimating - we don't know the foot fall of the events yet) - that will equate to 4 hours use which still sounds over the top!


Thanks,
Jack

 

[Jack155Q4]

We are very tempted by this. Compact and cheap.

I could plug the Scalextric transformer in to this and run it and have a car battery as a backup:
http://www.machinemart.co.uk/shop/product/details/clarke-720w-petrol-generator-g720