Electronic Splitter for Throttle Outpu

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Crash
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Electronic Splitter for Throttle Outpu

Post by Crash » Wed, 20 Nov 2013, 14:37

Just wondering if anyone knows where I may find a circuit diagram for an electronic splitter to convert one throttle output into two. I am currently running two throttle pots mechanically connected to output to the twin controllers on my EV. An electronic splitter would be more elegant solution and wouldn't drift out of balance like the twin pots do.

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Electronic Splitter for Throttle Outpu

Post by antiscab » Wed, 20 Nov 2013, 19:11

does the controllers take in 0-5v or 0-5kohms?
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Electronic Splitter for Throttle Outpu

Post by BigMouse » Wed, 20 Nov 2013, 19:53

If the controller accepts 0-5v (Hall-effect compatible input), then you can just use two op-amps wired as voltage followers/buffers with the single throttle as the input. You may even get away with just connecting the single box to both controllers, though you could run in to issues with voltage references depending on whether or not the throttle signal is isolated (doubtful).

If it is 0-5k ohm, then you'll either need to use a double-gang pot on a single throttle box, or digital potentiometers. There's probably other ways to do it though.

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Electronic Splitter for Throttle Outpu

Post by Crash » Fri, 22 Nov 2013, 06:08

Two resistive throttles connected to a 5v power supply from each controller, so I believe this means the controller throttle input is 0-5V.

Throttle used is one of these

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Electronic Splitter for Throttle Outpu

Post by RIPPERTON » Fri, 22 Nov 2013, 16:55

Both my vehicles have twin controllers and I use 1 0-5v pot throttle with a single 5v input from one of the controllers and then parallel the output back to both controllers. nothing fancy
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Electronic Splitter for Throttle Outpu

Post by Crash » Sat, 23 Nov 2013, 06:58

That would be very simple if it works, are there any risks of smoke and tears?

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Electronic Splitter for Throttle Outpu

Post by Crash » Sat, 23 Nov 2013, 14:49

A double channel digital pot sounds like a good idea to facilitate adding throttle programs.

I don't understand the voltage reference issue but this may have been what I had been warned about previously.

Also if the 5v input is coming from the controller is it possible / likely that there is more to the input than just the voltage?

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Electronic Splitter for Throttle Outpu

Post by BigMouse » Sat, 23 Nov 2013, 16:47

A 3-wire throttle connection from a controller will have 5v (usually), ground, and the signal. The 5v from the controller is a very steady, regulated power supply. I have never seen one than changes. It's extremely likely that the 5v is just the voltage.

The only time a voltage reference may be a problem is if, for some reason, the throttle signal is on the HV side of the controller internally. This is unlikely, but with Chinese controllers, you never know. It's easy to check though. Use a multimeter to check for continuity between the throttle ground and the controller's low voltage ground connection. If you have continuity, then you won't have a voltage reference issue.

Also, as far as I know, if you have a three-wire throttle connection, then the controller should be capable of receiving any 0-5v signal. A 0-5k ohm input would likely be 2 wire as the other half of the voltage divider would be internal to the unit.

If your controller can in fact accept a 0-5v throttle input (most these days can), then just use a single throttle box as others have described. Don't bother with the digital pot. It's a risky thing to install on the throttle and I would want to be very sure that you had some sort of fail-safe in place if you did go that route. If you want to be able to program throttle response, then use a microcontroller with a DAC, or even some sort of passive RC filter.

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