Maker Pro
Maker Pro

Adding LED lights to Kid Battery powerd Ride-on

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
Hi All,

I am getting my son a 12v battery powered tractor for Christmas and would love to wire it up to have working lights as the guy in the video did. I'm not after anything as complicated as this setup and would be more than happy to have the 4 headlights and 2 taillights operate off a simple on/off switch.

https://www.youtube.com/watch?v=pD-InblYDlk

Unfortunately my knowledge of electrical components and circuits is extremely limited however with some guidance on these I feel I could put this together ok.

LEDs - the LEDs used in the video were 1w whites for the headlight and 1w reds for the taillights. I will have to drill a hole through the plastic behind the supplied cover lens to insert/mount the LEDs. I will also have to apply some reflective tape or use a reflective lens and holder to help push the light out. Could anyone recommend what type LED would work best in this scenario and how best to mount it? would I need a heat sink?

Battery - here I have two options: 1. power the lights off the 12v battery that powers the motors or 2. add a new battery to power the lights. In the second option what size/type battery would be best to run the lights (preferably rechargeable)?

Resistor/Driver - this is where I get completely lost. Most videos I have watched about wiring LEDs talks about using a resistor but I have saw it mentioned that a resistor may not be the best thing to use with high powered LEDs. Would a resistor work and if so what size would I need? or would I be better using a driver?

Switch - I would like to use a red illuminated rocker switch so it will be easier to notice if he leaves the lights on.

Any help, recommendations or guidance would be greatly appreciated guys.

Thanks

Michael
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
Hi Michael.
Great project. There is a led resource section here.
It would be very easy to do what you want. However, to make things easier for you, you would be better off buying drivers for the particular leds you choose.
Also, read the specs on the leds and drivers. This will allow for correct battery size and voltage.
Ebay is a great source for drivers, leds, voltage converters/ regulators etc.

If you do a little shopping list with links, and be open to ideas, you will certainly get help from this forum.
Also, make sure you can get access to all the places you wish to put lights and run the wires safely.

Martin
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
Martin,

Thanks for your reply. I had a look at the LED resource and while I understand a little of it much of it goes over my head so I'm not entirely sure how to progress.

What I know - LEDs will be 1w (6nr) and the current battery that powers the toy tractor is 12V/8Ah no-maintenance sealed lead acid battery (unless I use a battery just to power the LEDs).

Circuit - would I be best running all 6 (4 front & 2 back) lights in a series circuit?

Components:

1. LEDs - would something like this be suitable ?

http://www.ebay.co.uk/itm/1-5-10pcs...ulb-Emitter-with-20mm-Star-Base-/131264746360

I assume I would drill a hole the size of the LED part (just over 8mm) and fix/glue in place with the star base behind.

2. Driver - I assume I need a driver? based on the battery spec and LEDs above could anyone tell me what driver I need?

3. Switch - something like this? http://www.ebay.co.uk/itm/250881112...49&var=550043931224&ssPageName=STRK:MEBIDX:IT

4. Wiring - not sure but probably the easiest bit.

5. Anything else I'm missing?

Thanks

Michael
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
Hi Michael,
Yes you can connect some in series.
Did you pay attention to the led resourse I linked to? I think not sir!!
Only joking... But there is some math involved connecting leds in series and the supply voltage.
I would recommend a seperate 12v sla battery purely from the point of view that when your son is driving etc, the leds would be dimming while the motors are loaded and get more run time. Also, you can charge it with the tractors charger.
1 watt leds are roughly 3.2v FORWARD VOLTAGE, and 300-350ma.
If you use a 12v battery, you need to keep the over all led voltage below the supply voltage. Connecting all six in series would mean:
3.2+3.2+3.2+3.2+3.2+3.2 = 19.2v. You only have 12v. You see the problem?
However, if you do a string of three leds in series:
3.2+32.+3.2 = 9.6v. Much better. It's below the 12v supply.
You can connect two strings and then connect them in parallel.
Next is the current, leds are current driven and need a constant current supply.
Add the current of each led and put another % or so for headroom.
So 300ma x six = 1800ma. Oops, 300x3=900ma for each string of 3.
A 1.2 amp supply should be fine
I am confusing myself now. Somebody will either agree, disagree or totally shoot me down here.
But the basics are there. So make sure the driver or drivers have a constant current to match the leds.

Martin
 

Arouse1973

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
No that's right Martin. Where you thinking of using an LED driver? If you do you will need 3, one for each parallel chain. Or you could look for one that will drive a series string of 6 LEDs.
Adam
 

Alec_t

Jul 7, 2015
3,650
Joined
Jul 7, 2015
Messages
3,650
If the forward voltage of the LED is 3.2V then two strings of three require about 600-700mA total. My concern would be that a simple switch for the LEDs could result in a flat (and damaged) battery if the LEDs were left on inadvertently. Won't you need a timer to switch them off automatically?
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
If the forward voltage of the LED is 3.2V then two strings of three require about 600-700mA total. My concern would be that a simple switch for the LEDs could result in a flat (and damaged) battery if the LEDs were left on inadvertently. Won't you need a timer to switch them off automatically?
Yep, just noticed that. Thanks.
I was too busy double checking my terrible math rather than the project at hand.

Martin
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
After watching this video
I found this regulator on eBay http://www.ebay.co.uk/itm/191620370200?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT.

This regulator would allow me regulate the voltage and current to where I need them.

Just thinking about the arrangement of the LEDs, there are 4 headlights and 2 taillights. The 4 headlights in series would require approx. 13v which would be too much so I assume I would be best doing them in 2 sets of 2 in series requiring around 6.4v and 600-700mA for the two strings.

The taillights will be red 1w LEDs which have a forward voltage of 2.2v meaning the two in series require 4.4v and 300-350mA.

Now if all 3 series are connected in parallel to the regulator I would set the voltage to say 6.5v and the current to say 900-1000mA, is this correct? Would it matter that the red tail light LEDs only need 4.4v?

On the subject of the timer it would obviously be desirable to protect the battery but I have no idea how to do it. The guy in the original video wired the lighting circuit in some way to one of the motors that drive the tractor so that if the motor was inactive for more than 5 minutes the power was cut to the lights. This would be great but unless someone could advise me on how to do it I will have to be happy with an illuminated switch to help me notice is he has left the lights on.

Again thanks for your help and opinions guys, keep it coming.
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
One other issue, if I use a separate battery for the lights I think I'm going to fairly limited for space for housing another battery. With the circuits as outlined above would a 6v battery to too light?
 

Alec_t

Jul 7, 2015
3,650
Joined
Jul 7, 2015
Messages
3,650
One of those regulators, set for say 300mA constant current, could drive a series chain of 2 head-lights plus 1 tail-light. So you'd need 2 regulators of that type.
A 6V battery won't do, unless you use it to drive a DC-to-DC boost converter which in turn could drive all 6 LEDs in series.
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
Hi mgfc,
No that unit only does voltage. You need constant current for driving leds. Two pots like in Julians video.
I see you have been doing some good research. Well done. Most posters wait for the leg work to be done for them:)
Alec_t has made some good points.
My thoughts on battery would stay with 12v.
As for space issues, is your sons' tractor the same 'John Deere' type in the original vid?
If so, you can easily glue a thin (6mm) ply under the 'hood'. Or have a false bottom in the trailer and all the electrics based there.
I am not sure how hot the 1 watt leds get. So it may be worth thinking about small mounting plates for heat dissipation too.
Remember, all these leds are being mounted to a plastic vehicle.
Don't get confused with the original video you posted. That is a micro controller and needs programming experience to achieve that.
The flashing and hazard etc can also be done via modules too. This project is really as wild as your imagination.

Martin
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
Thanks Martin. Ok so say I go with a 12v battery, why would I need two regulators? In Julian's video he was running a 2x3 arrangement of 1w LEDs, I would propose running a 3x2 arrangement, not sure why this need 2 regulators.
 

Alec_t

Jul 7, 2015
3,650
Joined
Jul 7, 2015
Messages
3,650
If you go with 12V, then you need 2 strings of 3 LEDs. Each string needs its own current regulator.
If you use a boost converter to get, say, 20V or so, then that could drive a single string of 6 LEDs and so need only one regulator.
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
Is the reason for the two regulators because of the different requirements of the red LEDs? I'm sure you're right, I would just like to understand why.
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
Thanks Martin. Ok so say I go with a 12v battery, why would I need two regulators? In Julian's video he was running a 2x3 arrangement of 1w LEDs, I would propose running a 3x2 arrangement, not sure why this need 2 regulators.
The math suggests Julians shouldn't work. But it does. It's a constant voltage and constant current regulator.
You could always buy two and see how using one works out. And if it works fine, use the second for something else.
The 3x2 and 2x3 arrangements would still have the same over all voltage drop whether it be 9x2 or 3x6, except the current will differ. 2x3 = 600/700ma and 3x2 = 900/1050ma.
But we don't know what the minimum voltage is for the led to turn on. 3.2v maybe the maximum. 1.2v maybe minimum.
Remember the leds are current driven, decrease the current and they will dim and vice versa. Decrease the voltage and they turn off.
But any sane person would take my maths with a pinch of salt. And do it themselves properly.!!

That's the only thing I can think of at the moment.
When you get the leds, see if they turn on at a lower forward voltage.

EDIT: just saw your post. I forgot about that bit.
Martin
 

Alec_t

Jul 7, 2015
3,650
Joined
Jul 7, 2015
Messages
3,650
Is the reason for the two regulators because of the different requirements of the red LEDs?
No. A string = 2 white + 1 red. There would be 2 strings, hence 2 regulators.
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
Ok I need to start thinking about the wiring layout for this.

My components are now:
1nr 12v battery
1nr switch
2nr Volt/current regulators
4nr 1w white LED (3.0-3.6V max, 350mA max)
2nr 1w red LED (2.0-2.6V max, 400mA max)
Wire

Working on the basis that I'm having two strings of 3 LEDs (2 white +1 red) each with a regulator.

I connect the battery (+) to the switch, the switch to the regulator (+ in), The regulator (+ out) to the LED 1 (+), 1 to 2 to 3 (- to +), LED3 (-) to regulator (- out), regulator (- in) to the battery (-).

Now if that is all correct how do I connect the second regulator and string of LEDs? Does the second regulator (+ in) also connect to the switch and then regulator (- in) back to the battery (-)?

Do I need a particular type of switch?
 

Martaine2005

May 12, 2015
4,965
Joined
May 12, 2015
Messages
4,965
Yes, that seems correct.
The second regulator is wired the same as the first.

The switch would depend on the amperage. As does the wire gauge..
A 2amp switch would probaly suffice. However, I would go quite a bit higher maybe 5 amps so you have plenty of headroom for additional devices. Going higher is never a problem, going lower is.

You should also put an inline fuse too between the battery and switch. A 2 or 3 amp fuse will probably be fine for this.
It depends on the total current being used by the regulators and leds.

Martin
 

mgcfc

Sep 24, 2015
23
Joined
Sep 24, 2015
Messages
23
thanks martin.

Do I need a switch with extra poles to connect to both regulators?

What would the best method be of attaching both return wires to the battery's negative terminal be?
 
Top