Potentiometer Install on Razor Pocket Mod

[ks61]

I am trying to install a potentiometer on my daughter’s Razor Pocket Mod, since it will be a bit too fast for her out of the box. I don’t have any electrical know-how (I’ve installed light fixtures, outlets and switches around the house, but that’s it); however, I can follow a tutorial. There are some good ones on YouTube for other Razor products, but not the Pocket Mod and the wiring configuration is different. Could anyone advise on how to install a potentiometer on a Pocket Mod (version 47)? I’ve attached a wiring diagram. Thanks in advance!

 

[calab]

I heard from several Razor upgraders on video that the throttle is on and off there is no ramp up which is why I believe the throw of the throttle is so little, that and its for tiny children hands. The throw is the total swept area of the throttle from off to max, which I never felt before until I bought a Razor E200 a week ago to heavily modify. Resistors inline with throttle may work so search for Razor throttle resistor slow speed. Shaving controller shunts reduces power, buying a lower watt brushed controller is $25.

 

[e-beach]

So the assumption is that the scooter is too fast. Is that correct? Also, you didn't say what you plan to use the potentiometer for. Is it to reduce throttle voltage to the controller so to slow the scooter?

Please clarify your intention.

 

[ks61]

Yes, the purpose of the potentiometer is to slow it down. The Razor Pocket Mod goes up to 15 mph, which will be too fast for my 8 year old initially. She’s a cautious kid and I know the speed will intimidate her, so I want to be able to limit the speed (in an adjustable way) so that she can get comfortable riding it before she can access the full speed of the scooter. As I said I’ve seen several videos on YouTube of potentiometers being used on Razor Quads, but the wiring situation is different and I don’t know how to translate it to the wiring situation in the Pocket Mod. Here is an example of one of the videos that I’m referring to, and what I’m trying to accomplish for the Pocket Mod: https://youtu.be/ekrUJtObbn0

 

[calab]

You need to find the wiring layout of the Razor quad and figure out what that green wire is.

If yours is the same as the diagram, 4 wires 2 brown 2 orange, then just pop one wire out at a time and see what happens. Start with the green wire on the controller side and figure out what it connects to. Measure the voltage of each wire with the controller on, ignition switch on. On the controller side the red will be positive voltage, green could be ground or the yellows could be ground, 2 grounds on a throttle is confusing.

 

[ks61]

The colors are the same as the wiring diagram. There are two brown and two orange wires running from the throttle to the throttle connector, and one green, two yellow and one red wire running out from the throttle connector to the controller.

 

[calab]

Do the mod on the green wire controller side, my Razor E200 stand up scooter has 4 wires 2 red 2 black on throttle side, red, yellow, 2 green on controller side and it is just an on or off, the same as hooking a battery up straight to the motor the motor is either on or motor is off.

 

[ks61]

Thank you for the suggestion!

 

[amberwolf]

As long as the controller itself has a "normal" throttle input, then first verify the connector wiring:

Use your voltmeter on 200VDC, with the black lead on battery negative of the controller. Turn on the scooter. Red lead on red throttle connector wire should get about 5v, if that's power to the throttle.

Red lead on green wire should get about 0v; hold wheel offground and slowly turn throttle--if it suddenly jumps to a steady voltage and doesnt' change more, it's an on/off throttle. If it slowly changes form about 0v to about 5v, (or from about 1v to about 4v), it's a normal throttle that can vary the speed.

Red lead on yellow wire (each one) should get about 0v, if they're ground.

If so, you can install the pot on that green wire, regardless of what kind of actual throttle is used:

Cut the green wire halfway between controller and connector.

Center wire of a 5kohm to 10kohm pot goes to the green wire on the controller side.

"top" wire of the pot goes to green wire on connector side.

"bottom" wire of the pot goes to ground; this gets spliced in like a "T" to the black wire.


Adjust the pot to the center, and it should now have about half the max throttle ability. Adjust up or down from there to suit your needs.

This does not just limit the max speed, but also the max acceleration.


If the wiring didn't measure out as noted above, then post what readings you did get so we can figure out where to put the pot.


BTW, another option is to replace the on/off throttle with a regular throttle (potentiometer type, not hall type), rather than adding the pot, and then she'd be able to control the speed herself. Or you can actually add a "limit screw" or pin to prevent the throttle from being physically moved beyond a certain point, but if she's the cautious type as you say, she'd probably do fine with controlling it herself.


If the controller itself is just an on/off type, then you may have to open it up to install the pot to limit it, and do some investigation of the circuitry inside. (which we can help you with). Some of those are potted solid, and may require dissolving the potting. It's probably easier to buy a new (brushed) controller that does have a normal throttle input, than to do this.

Also, some of these don't use actual controllers at all. They use a board with relays (like this one:
https://endless-sphere.com/forums/viewtopic.php?f=35&t=89541
but if you have a metal heatsink-looking box then yours probably does use an actual controller, which probably does have an actual variable throttle input.