# 24VDC Scooter Motor Control

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#### Justin Fry

My son's razor E100 scooter stopped working and I believe it's the motor controller. The scooter stopped moving, I checked the motor and fuses and they all work. So that leaves the throttle cable and motor controller. You cannot purchase the motor controller any more so I wanted to just build the circuit myself. Anyone have suggestions on circuit layout or recommended sites with circuit diagrams I could use as templates? The throttle I believe works like a linear POT to adjust the resistance on the controller which controls the speed. Maybe it's the throttle cable, any suggestions?

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#### Bob Hogg

If you simply by-pass the Pot - make sure the back wheel is off the ground - that will tell you if that part of the circuit is working.

I would highly recommend you look on eBay - there is a very good chance you will find it there.

Bob Hogg

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#### Ken E.

It may be a simple PWM amplifier if the motor is a DC brush motor. You could buy one that takes a linear (Potentiometer) input signal. If its a brushless DC, you will have to have provisions for commutating it such as Hall switches in the motor.

~Ken

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#### peter berry

search cheap dc motor control with or with out pulse width modulation and you might find any number of small circuits that might work, or there are small dc drives called kbic. they work with a veriety of dc supplies, i.e. 12 and possibly 24 volt and also other voltages. full control and config settings are common with all drives now. mounting and hiding the dc drive might be the problem, and you might need to check out how the drive might as the battery goes flat will this affect the drive. you might have to do somthing special like use the 12 volt version on a 24 volt supply with a regulator circuit. while the batteries are going flat the regulator constantly supplies the pc board with 12 volts while the controlled motor voltage runs between max output and min output. good luck and happy
building or should i say rebuilding.

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#### ken

Did u ever get a resolution to this problem? I have a similar problem.

It appears that the throttle isn't adjusting the speed. I have the whole unit apart. I start the wheel and it runs wide open, no throttle adjustment allowed, the only way to stop it is to engage the brake which appears to disengage the voltage to the motor?

any schematics or ideas?

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#### JimSmith

One of my nephews has the same scooter/problem. First of all, no mfr. is going to produce a proportional FET controller for a $130 scooter..... the circuit is a simple time-varied relay circuit that applies the full 24V to the motor at interval on/off times which are varied by the speed control. It is the cheapest implementation of speed control I have ever seen. If I can't get Razor to send me a schematic, I may draw one myself for possible repair. The relay is a$3 part; its demise is suspect based on its use in the circuit. The best way to test the relay is to open the controller circuit and poke a hole in the relay at the point where you can manually activate the relay to check the contacts. If the motor runs, then the relay contacts are probably good; the timer circuit could be bad. It is a two-transistor astable multivibrator whose duty cycle is varied with the speed control. One of the transistors could be bad, etc. If Razor does not help, I will definitely publish my findings to the general public with details on a simple repair. I've found that knowledge can be a great motivator in may cases.

Any help with schematics would be appreciated. THanks.........

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#### Anonymous

We had a E100 scooter in the shop last week. Firt of all these little scooters dont have PWM control, the circuit simply wont start the motor until you manually push it to 3Km/h to prevent the motor from burning out. The simplest way to fix this board, if the relay and throttle switch(not a variable switch) are still good, is to simply bypass this circuit. You still have to push start the scooter so the motor won't burn out, but the motor can now be switched on at any speed. First locate the two inputs from the throttle and brake on the circuit board and jump it to the + relay so when the throttle is pushed current flows from possitive through both throttle and brake switches and into the relay. Cut the original link to this post by cutting into the board with a knife to prevent smoking. Then connect the other side of the relay to - Battery. Now when you hit the throttle the relay simply turns on and the scooter works again. A simple fix to an expensive repair.

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#### larry

I bought one at a yard sale and had to replace the batteries but it still wouldn't work until I read this article as I tried to have it start from a standing stop.

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#### nev

i have the same problem i have tested the battery but when i try to turn my scooter on NO power comes through to the switch or to the batery life i cannot find a BLDC motor driver and am not sure now what to do?

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#### CSB

I am having a problem with a Scoot-n-Go scooter my friend gave me.

We converted it to an electric lonboard, and in the process of moving the torn-down scooter one of the turn signals got crushed.

After it got built, I was testing everything (which worked) until I switched on the broken turn signal (silly me) and fried the electronics...

So I found the turn signal flasher relay that melted... would this relay prevent the whole thing from running? I ordered one and it should be here in a week, but I don't see how a turn signal flasher would prevent EVERYTHING from working, or if I need to replace the controller as well.

Thanks

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#### Mike H

These are simple circuits. I made a schematic. The SCR, Q1, seems to be bad. If you jumper the anode to the kathode then it works fine. The replacement part is MCR 100-6 and is less than 50 cents.

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#### Bill

>These are simple circuits. I made a schematic. <

Please post a schematic using MCR 100-6 and or exsiting Laser circuit diagram.

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#### William Hinton

There is a surplus electronics store that carries controls, motors and gear systems for various scooters etc.. They may have exactly what you need and if you need to repair the transistor control they carry 60 amp MOSFETs and other components as well.

I hope this helps,

William Hinton

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#### buttereeeze

A temporary-on bypass switch worked (hate to do it like that for now but I did ride down hill TODAY and got a smile!) Now seeking higher amps off the battery supply somehow. Straight 24vdc to motot didn't seem to meet 18mph, 8 hours spec. Could be I'm 250lbs. I don't konw what I'm doing.

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I wish I had seen this post before I bought the new control boxes. They are available on Razors web site for $13.95 plus tax. However, I did not know about the three km/h for testing. After I put it on a lift to get the back wheel off the ground, I spun the wheel and it started right up. As far as the questions about how to bypass the controller, a simple 24V relay should work using the GO button to control the relay, but it would eliminate the safety of cutting off the ciruit when the brake is held. As far as the strength of the motor, it makes sense to have it take off after getting up to speed and the speed will be proportionate to the weight of the passenger. X #### xkfalcondeluxe I used a relay on my Razor Electric Scooter and made a video of me doing it: >I wish I had seen this post before I bought the new control >boxes. They are available on Razors web site for$13.95 plus
>tax. However, I did not know about the three km/h for
>testing. After I put it on a lift to get the back wheel off
>the ground, I spun the wheel and it started right up. As
>far as the questions about how to bypass the controller, a
>simple 24V relay should work using the GO button to control
>the relay, but it would eliminate the safety of cutting off
>the ciruit when the brake is held. As far as the strength
>of the motor, it makes sense to have it take off after
>getting up to speed and the speed will be proportionate to
>the weight of the passenger.