M.L. Toys
M.L. Toys
HobbyMasters M.L. Toys
vehicles with a circuit board controlling the motors
By RadcliffeRed
Hi All

First post, so please be gentle.

I bought a toy car for my sons birthday recently, which he loves, it could just do with a bit more power, it struggles as soon as it hits the slightest incline and it could do with a bit more speed in general.

The problem i have is i dont even know who makes the car as the instruction booklet has no details of manufacturer, so that has made by search on this site a little difficult.

Its a yellow aston martin, link below

Apologies for the lack of details, but any help what so ever would be much appreciated. Im not great with electrics hence my request for help.



JP is the master of wiring.... he is amazing.

If you want a quicker (dirtier) solution to try first, just replace the 6V battery with a 12V one. You will get a lot more power / speed out of that.

You MAY fry the circuit board on 12V, that is what J's diagram addresses. It will work great, mine is a cludgier way, and you may fry the board. Try mine at your own risk!

I don't have this particular model, so maybe someone else who does can chime in on the ability of it to handle 12V.
Last edited by TerryInLeesburg on Wed Jun 15, 2011 11:20 am, edited 1 time in total.
User avatar
By jparthum

Thanks Terry - I'm certainly not the master though :oops: - more of an eager student of the great wealth of knowledge here. :D

I've purchased from Newark before, and the shipping ended up being free for my order :? . Their policy is to calculate shipping after you place your order (which is more accurate than estimating before, and cheaper than charging a flat-fee), but in my case, they lowered the price of my parts by about the same amount as the final shipping total - I'm not sure if it was a mistake, a simple price update that was coincidental, or if maybe they were trying to 'win me over' on my first order. Either way, I was very happy with the whole experience, and will likely be ordering most of components from them now. :)

Quick FYI; The Relay that you linked to is designed for a Printed Circuit Board (PCB), so it would be a little more difficult to connect wires/connectors to :( .

I've successfully used the Relays that I linked to at 6V and 12V :) .
By RadcliffeRed
Cheers guys, i initially thought about just changing the battery but thought this may cause problems, i had heard this would burn the motor out.

Terry, you mentioned that it would burn the circuit board out, is this because the power would hit the board before the motor (please excuse my stupidity). What, in your professional opinion would be the chances of frying the board?

Jp, thanks for the diagram im trying to get my head round it, so i have a few questions if i may.
1) What exactly do the relays do?
2) Why is there 2 of them?
3) Would a 6v relay handle power from a 6v battery?
4) Would the 6v motors not burn out from the 12v battery?

Im guessing the shipping costs to England will be quite high from Newark, i might have to find somewhere a bit more local.

Guys, thanks again, its hugely appreciated.

User avatar
By Nighthawk
The relays allow you to provide 6V to the circuit board, as that is what it's designed to handle. There's a risk that 12V might burn it out. When the circuit board supplies 6V to the motor wires, those will be rerouted to the relays. When the relays see 6V on their inputs, they close the 12V circuit and supply power to the motors from the 12V battery.
User avatar
By jparthum
Sorry, didn't notice that you were in England :oops: . 'Farnell' is the European counterpart to 'Newark'. Here is a link to the same Relay on their site... ... tt=30M9197

Electronic devices (as opposed to Electrical devices) are much more sensitive to Voltage and Amperage (or 'current'). Since you car has a remote control feature, it utilizes Electronics - at least for communications, but likely for all motor controls - so sending double the Voltage through those electronics would quickly damage it, or invoke it's circuit protection. The motors will have a higher tolerance for over-Voltage, though how much tolerance will depend on your specific motor(s), which I have no knowledge of :? .

A Relay is simply an electrical circuit switch that can be operated by a separate circuit - similar to the vehicle's existing remote control system, which uses a low power device (the hand-held unit) to operate a separate, high power device (the vehicle drive-train), Relays can use the (relatively) low power output currently connected to the motor(s), to operate an even higher current (12V) circuit which could be connected to the motor(s) instead. This would even further remove the existing high current load (motors) from the circuit board - There would then be no high current at all passing through the circuit board, which would preserve it's functionality even more than now. And having a dedicated 6V battery for the circuit board, also means that it is much less likely to be drained too low, which would also increase the current on the circuit board, and potentially cause damage.

Two Relays are needed because your motor(s) receive power in two polarities, depending on the direction they are being signaled to rotate (Forward or Reverse), so one Relay serves as the 'Forward Relay', and the other serves as the 'Reverse Relay'. When neither Relay is receiving a signal from the controller, electro-braking will be automatically applied - I don't know if the vehicle currently has electro-brakes, but they would become a more important safety feature at 12V / double the current speed. :)
Last edited by jparthum on Wed Jun 15, 2011 4:29 pm, edited 1 time in total.
By RadcliffeRed
Thanks again Jp, this is all making a bit more sense now. im going to open the car up tonight and see what is already in place and see if i can make sense of it. Hopefully there will be enough room for a new battery and relays etc.

Hopefully one final question, in terms of what to buy, do i just need 2 relays a new battery and some wiring? And if so what wiring? Do the different colours represent something (apologies, that was 2 questions)

I will be in touch when i have started the MOD to let you know the results.

Thanks again.
Rad.... What JP said. ;)

For wiring, I found the cheapest, and easiest to get is the low voltage wire that people use for those little outdoor patio lights. It is 12 gauge (which will handle a lot of power), easy to find, flexible and cheap.

I can get it at a home center for $0.53 per foot for two conductor wire. If you only need one, then you can split the wire and it only costs you $0.27 a foot!
User avatar
By jparthum
Yeah, you can use the cord from an old, broken appliance, or an extra extension cord, speaker wire, etc. All that really matters is that it is thick enough (I wouldn't go below 16AWG / thicker wire has a lower number), and preferably is 'stranded' (multiple small wires inside of one insulator, instead of one thick wire like 'Romex'). I'm not sure if 'American Wire Gauge'/'AWG' is used across the pond :? , so you may need to cross-reference. If you could possibly place the 12V battery and Relays near the motor(s), you will need much less wire, and the thickness of the wire will become less of an issue (longer runs need thicker wire). Note: The thinner wire that connects the 6V Negative terminal to the Relay coils' Negatives can be very thin wire (telephone line/CAT3?) because it will draw very little current. This can also be connected anywhere between the 6V Negative and where that Negative wire meets circuit board - wherever is more convenient. If you are able to mount the 12V battery and Relays near the motor(s), then this thin wire should end up being the only new wire that is more than few inches long. :)

I intended to include a legend for the wire colors, but overlooked that :oops: :
  • BLACK = [-] NEGATIVE (both 6V and 12V)
  • RED = [+] 12V POSITIVE
The Orange wires from the Circuit Board to pin 86 of the Relays are the existing motor wires, they just need to be relocated - if you only have one motor, just ignore the bottom motor and the associated wires connecting it to the top motor. All of the other wires connected to the Relays are new wires (and of course, the 12V battery).

Can't wait to see it! :)

EDIT: Would you mind if I moved this thread to the Low-current 6V vehicles section? It's not off-topic here or anything like that - I just think it would make a good candidate for that lonely, empty section :cry: . I'm not sure if this will break any current subscriptions though :? - If so, we would need to browse to it, and re-subscribe. :|
Last edited by jparthum on Thu Jun 16, 2011 1:58 pm, edited 1 time in total.
By RadcliffeRed
Cheers. Yes im happy for you to move it,

Im afraid to say though i had a look tonight and there were so many wires i wouldnt no where to start, im going to have to acquire some help. i have someone in mind, so its going to take a while longer.

Thanks for all your help. I will be back...
User avatar
By jparthum
WOO-HOO! First post for this section! :)

There are only three original wires that need to be located:
  • Battery Negative
  • Motor Negative
  • Motor Positive

So my Kids wanted faster but not much going for Be[…]

I’ve got the old school original kid trax fi[…]

I recently upgraded my kids Dora Jeep from 6v to 1[…]

"Best Choice" Jeep?

Best Choice Products (BCP) Jeep 24v Upgraded from […]

HobbyMasters Udemy Course