How to connect 4-wire throttle to a 2-wire controller?

kmxtornado

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Hi, thanks in advance. I have this old school thumb throttle with integrated voltage meter from 11 years ago. I'm replacing my controller, but the throttle wires on the new controller only has 2 wires. How do I make the connections? My guess is that two of the 4 wires are for power to light up the voltage display and the other two wires are for the throttle itself. If so, which wires are which?

The new controller has a display function whereas the older one does not. Not sure if that matters.

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What does the wiring diagram on the new controller say? Never seen a controller with only two wire inputs for a throttle.

Your old throttle probably has
1. Battery Power
2. +5V to power throttle
3. throttle signal
4. ground

If you bought a stand alone throttle, you still would get something with three wires, everything above except battery power,
 
I'm pretty new here but will share what I do know for what it's worth:

For all the four wire throttles I've seen, Red has been =+5V, Blue/Black=0V, Green= 0-4.2V throttle signal, and Yellow +48V (or whatever your full battery voltage is).

If it were me, I would apply +5V on red and 0V to Blue, and measure voltage between green and blue to see if applying throttle causes green voltage to increase. Then once you are confident in these three connections I would try full battery voltage on Yellow-Blue, to see if this makes the battery display work.

There is no standard so yours might be different, if you get it wrong you might fry the throttle hall sensor, especially with the full battery voltage test. I would be happy to do this test on my own throttle knowing that a replacement would cost about $10.

The controller is a different story, and more expensive to replace. It is worth posting photos or some way of identifying exactly which new controller you have so someone else can help you more. Usually there are three wires for throttle: +5V,0V, and 0-4.2V Signal. If there are no markings on the two wires you mention, I would open the controller to see if there are any markings on the circuit board where the two wires are soldered on.

Some throttles use potentiometers instead of hall sensors, and I'm not sure if this is what your controller is expecting given it has only two wires.
 
Is it a hall throttle, or potentiometer?

If it's a hall, it requires three wires, and won't work on that controller--the controller is not designed for this kind of input and you'd have to change the throttle to the kind it expects. (it could blow up the hall sensor, or cause the motor to not run or to run full out always or always run a little even when no throttle movement is made, etc).

If it's a potentiometer, it only requires two, though most controllers use all three.

Set your multimeter to 20 k ohms, and put the red lead on the first wire of the throttle unit. Move the black wire to each other wire, and note down the readings on each. Move the red to the next wire, then the black wire on the next two wires, noting down each reading. Repeat for the next one. This tests for resistance between each one. If it's a 3-wire potentiometer, one pair of wires will read around 5kohm, 10kohm or so. Another pair will read close to zero ohms, or actually zero, or nearly the same as the first pair. That pair, when you move the throttle, will change it's reading. When you find the pair that changes from zero to full resistance (whatever the ohms is), that's the signal and ground.


A pair that includes the voltmeter probably wont' read anything (OL on the meter, or whatever it shows for no connection).


Which one is ground depends on how it's wired with the voltmeter. If there were three wires for the pot, the ground is common with the meter. If theres' only two wires for the pot, the meter is probably the other pair of wires, and it doesn't matter which is ground on the throttle wires. But which one is ground for the meter does matter; it may blow up the meter if you hook it up backwards. You'll probably have to test using the original controller (even if it doesn't work to drive the motor) to find out which is which, by measuring voltages on it's connector pins using the battery negative as the black meter lead connection point.

Also, some controllers with only two wires do not actually have a throttle input, only a switch input (even if it's called throttle). (like those on very low-powered "kick scooters"--these don't even use FETs but rather relays inside the controller).

In any case, I've only seen two wire throttles on brushed controllers, so if your motor is not brushed, my guess is this controller isn't compatible with it, though I've not yet seen a brushed controller with a display, either.

For us to do more than guess about that and other things you'd need to post complete details about the system you're fixing up or building, along with links to any of the items you've bought to replace things with.

kmxtornado said:
Hi, thanks in advance. I have this old school thumb throttle with integrated voltage meter from 11 years ago. I'm replacing my controller, but the throttle wires on the new controller only has 2 wires. How do I make the connections? My guess is that two of the 4 wires are for power to light up the voltage display and the other two wires are for the throttle itself. If so, which wires are which?
 
cloudy said:
I'm pretty new here but will share what I do know for what it's worth:

For all the four wire throttles I've seen, Red has been =+5V, Blue/Black=0V, Green= 0-4.2V throttle signal, and Yellow +48V (or whatever your full battery voltage is).

If it were me, I would apply +5V on red and 0V to Blue, and measure voltage between green and blue to see if applying throttle causes green voltage to increase. Then once you are confident in these three connections I would try full battery voltage on Yellow-Blue, to see if this makes the battery display work.

There is no standard so yours might be different, if you get it wrong you might fry the throttle hall sensor, especially with the full battery voltage test. I would be happy to do this test on my own throttle knowing that a replacement would cost about $10.

The controller is a different story, and more expensive to replace. It is worth posting photos or some way of identifying exactly which new controller you have so someone else can help you more. Usually there are three wires for throttle: +5V,0V, and 0-4.2V Signal. If there are no markings on the two wires you mention, I would open the controller to see if there are any markings on the circuit board where the two wires are soldered on.

Some throttles use potentiometers instead of hall sensors, and I'm not sure if this is what your controller is expecting given it has only two wires.

This is the wiring diagram for the controller I bought. I was wrong in my original post. Mistakenly wrote 2 wires, but now I see there are 3 wires for the throttle:
bunwGYH.jpg
 
amberwolf said:
Is it a hall throttle, or potentiometer?

If it's a hall, it requires three wires, and won't work on that controller--the controller is not designed for this kind of input and you'd have to change the throttle to the kind it expects. (it could blow up the hall sensor, or cause the motor to not run or to run full out always or always run a little even when no throttle movement is made, etc).

If it's a potentiometer, it only requires two, though most controllers use all three.

Set your multimeter to 20 k ohms, and put the red lead on the first wire of the throttle unit. Move the black wire to each other wire, and note down the readings on each. Move the red to the next wire, then the black wire on the next two wires, noting down each reading. Repeat for the next one. This tests for resistance between each one. If it's a 3-wire potentiometer, one pair of wires will read around 5kohm, 10kohm or so. Another pair will read close to zero ohms, or actually zero, or nearly the same as the first pair. That pair, when you move the throttle, will change it's reading. When you find the pair that changes from zero to full resistance (whatever the ohms is), that's the signal and ground.


A pair that includes the voltmeter probably wont' read anything (OL on the meter, or whatever it shows for no connection).


Which one is ground depends on how it's wired with the voltmeter. If there were three wires for the pot, the ground is common with the meter. If theres' only two wires for the pot, the meter is probably the other pair of wires, and it doesn't matter which is ground on the throttle wires. But which one is ground for the meter does matter; it may blow up the meter if you hook it up backwards. You'll probably have to test using the original controller (even if it doesn't work to drive the motor) to find out which is which, by measuring voltages on it's connector pins using the battery negative as the black meter lead connection point.

Also, some controllers with only two wires do not actually have a throttle input, only a switch input (even if it's called throttle). (like those on very low-powered "kick scooters"--these don't even use FETs but rather relays inside the controller).

In any case, I've only seen two wire throttles on brushed controllers, so if your motor is not brushed, my guess is this controller isn't compatible with it, though I've not yet seen a brushed controller with a display, either.

For us to do more than guess about that and other things you'd need to post complete details about the system you're fixing up or building, along with links to any of the items you've bought to replace things with.

kmxtornado said:
Hi, thanks in advance. I have this old school thumb throttle with integrated voltage meter from 11 years ago. I'm replacing my controller, but the throttle wires on the new controller only has 2 wires. How do I make the connections? My guess is that two of the 4 wires are for power to light up the voltage display and the other two wires are for the throttle itself. If so, which wires are which?

Sorry for my mistake, it looks like there's actually 3 wires - not 2 like I previously posted in my original post. Sorry, old 41 year old eyes and getting to me apparently. So from what you're saying, it looks like I have a "hall" one. But which of the 3 wires do I use and which to connect to which wire?
 
Don't know which kind the controller expects; the original website for it might say, or it might give a voltage range it expects on the input. Commonly when I see throttle wiring with brown, blue, black, it's for potentiometer throttles, with brown being signal, blue being power, black being ground.

What it is for this controller, you would have to test or risk blowing things up. If you power on the controller, set a multimeter to 20vdc, put it's black lead on your battery negative, and then test red lead on each of the three throttle input wires, noting down the readings on each one. That will tell you which is 5v, and probably which of the other two is which, as groudn will be 0v and throttle in might be slightly above that. If they're both 0v, then you can disconnect power and use the meter on continuity or 200ohm range, to check from battery negative to each of the non-5v wires. Whichever reads continuity or 0ohms is ground.

You'd still need to determine what the original throttle is, to know what the response of the controller will be, and what to do to change it if necessary. This may be determined by the suggested testing, or by checking the original controller as suggested (the easiest way to figure out the wiring).

So....links to the new stuff and as detailed information about the old stuff as possible will help us help you (this is always a good idea with any question).
 
Yeah, unfortunately the original controller is 11 years old and resold from a company called Hitekbikes which is no longer in operation. They used an Amped Bikes controller. They're still around I believe, but the controller is still very old so no record. The photo in the post above unfortunately is all I have for a wiring diagram for the new controller.

Yes, I'm definitely concerned about blowing stuff up. The controller isn't too expensive, but wait time for delivery was several weeks so would rather not break anything if I don't have to. I guess Im' not really sure what specific questions to ask. I can always relay questions to the manufacturer which is KT to get some answers.
 
Even though I'm retired I value my time. Sometimes repurposing parts is a false economy, for me. I'd get a KT throttle and be done with it.
 
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