PWM -> Vexplorer motor adapter

I’d like to see a PWM (3-pin) to Vexplorer motor (2-pin) adapter so that I can run a Vexplorer motor from a Vex PWM port. This would allow more parts sharing between Vex Classic and Vexplorer.

If designed right, it could allow Vexplorer aux accessories like the flashlight to be controlled by a digital output port (not just PWM). This would also be handy for tinkerers like me that want to drive relays and such from a Vex controller.


  • Dean

Your describing the IFI Victor 884 Speed Controller, (which is classic Vex Controller Compatible) but for very little current…

Yep, or any of several other small PWM->DC motor controllers like the Sabertooth modules. The major distinctions I see with this product are:
*]This is a Vex product and has all the right keyed Vex connectors
*]This is a very low current device that draws the motor power via the PWM cable
*]Low cost - $10ish - the Victor costs almost as much as the Vex Micro Controller
*]Simple - The Victor and Sabertooth have various switch settings and/or jumper settings that you have to figure out. I see this as a way to make a Vexplorer motor act like a Vex Motor, or as a switch to turn the flashlight on/off

There are plenty of higher-power higher-priced solutions already out there, and I don’t really expect Vex standard parts to play in that space.

Oh, and for bonus points, it would be cool if it had an analog input you could plug one of those new Vex potentiometers into and make the thing act like a servo instead of a motor. Would probably drive it out of the price-point sweet-spot, but it would be an interesting capability…


  • Dean

Coming soon. :smiley:


Cool - Thanks for the nibble!

PM me if you need any beta testers :smiley: … for anything :smiley:


  • Dean

Sweet, you get 2 motors for $20 with the vex explorer.

I have always wanted to use this motor because it is differnt in its size, its longer and does not protrude very far out like the regular motor.

Is there a time frame on when this product will be available?

I mean they are just a 3 to 2 pin connectors so will it be available soon or much later like august.

It may be harder to build depending on the way the vex motors switch directions if it is just reversing the polarity then it is really simple but if it is a signal sent through the cable to the motor and then the motor switches depending on the signal it could be harder to produce because you need to duplicate that circuity in the connector.

Yep - this is exactly why I’m interested in this product

Vex motors & servos take a logic-level PWM signal and do the switching / speed control themselves. Vexplorer motors are just DC motors that need the receiver/controller to do the switching. So, there will have to be some electronics in the adapter.

There are a few 1-chip solutions that take PWM and drive a small DC motor, so my guess is they’ll just put one of those in a small case with a 2-pin socket. I’m curious if it will be single-channel, or if they’ll go ahead and make it a dual-channel adapter…


  • Dean

I can’t wait!!!

I have liked to integrate the vexplorer with my designs (even though I end up having two remotes and two batteries)because they are a good size for certain apps.

What would be really cool is if i knew when these were going to be released.

I just want to know when these will be out.

Also if vex wants $10 for 1 don’t even buy it.

Open the vex motors and reverse engineer the circuit and then order enough parts to make 10 for the same price.

I’ve priced the parts for a PWM->DC adapter, and I think $10 would be hard to beat as a DIY project. A PWM capable motor driver chip costs about $3 each in small quantity (A3953=$3.02, A3968=$3.13). Or, they’d need a small microcontroller (ATtiny13=$1.94) and an H-bridge (SN754410=$2.35). I guess they could make something out of discrete parts that might be a bit cheaper.

Of course IFI will get quantity discounts, but you also have to consider the cost of other components, wire, connectors, PCBs, the enclosure, assembly, testing, shipping, returns, etc. And lets not forget that IFI is a business and needs to make some profit.

As a reference point, you can buy a 2-channel PWM->DC board for $60 (5amps/channel).

On the other hand, I do encourage you to try and build your own PWM->DC controllers, as well as other Vex accessories. It is a great practical learning experience, and is lots of fun. If you can save money in the process, even better. If you have success, please post your results!

We’ll have to wait to find out the price and specs, but IMHO, $10 would not be an unreasonable price for IFI to charge for such an item.


  • Dean

I have so much electrical stuff now.

I have everything needed to design and prototype pcb boards from a drill press to the copper clad boards and the acid.

I also have

Lots of tools, soldering voltmeter, caliper ect…
HUGE capacitors 2x500 joule and 6x250 joule lol! (Gotta Love ebay)
6x50amp solid state relays
Assorted LED’s and resistors
All sorts of ic circuit ie 555 timers
30 ds pics
And so much more…

So yea, i may try and build a speed controller.

While i am at it why don’t i hook up a charged 500 joule capacitor to the vex motor i am sure it would increase the power output lol!

Thanks! I’ve already ordered mine…

  • Dean

Isn’t this kind of pointless?

At $10 each i would need to buy 2 of those and a vex explorer motor pack for $20.

By then i have spent $40 which is the price of 2 vex motors.

I really wanted to see these for $5, but i guess thats just my opinion. I don’t know how much it costs to produce these so it may be a fair price i don’t know.

It does offer more possible configurations for tight spaces. Also, you could probably drive more than one VEXplorer motor from one adapter using a Y cable. *

I am assuming that they can be used to drive lamps and relays and other small DC loads. That opens up, or at least simplifies, a whole lot of options.

Depends a lot on the build quality. At the volume they are going to be shipping, $10 seems like a fair price to me. If they were selling hundreds of thousands of them, then maybe $5.


  • Dean*

Than again i did not think about the possible uses in driving small current loads from the adapter because its output is + and - witch you could drive relays, leds, small non vex motors, and all sorts of other stuff.