Remembering I had a 3" Chevy throttle body and was bored I hooked up a PWM. First thing I noticed is this specific TB really only works in the ~2-4 volts range. I know @ccweb1 has played around with an electric throttle body, how did you go about trying to control it? Did you make up an Arduino controller or just use a PWM? I’m using a 5v power supply and the PWM I have is using a 100k potentiometer. Do you think switching to a 10k or 5k pot would make it less sensitive? It’s really touchy.
I wonder if leaving it wide open for gasoline driving would eventually damage the motor?
For reference the throttle body I’m using is a RME87 that is technically NOS but was being thrown out when I worked at the dealership.
I’m just using a purchased PWM motor controller right now, I mentioned the resistance of the Pots because all the controllers I have are using 100k Pots.
So I would wire in the PWM output to the Arduino or would I need to make my own PWM for the Arduino to use?
Hi Cody,
i use 2 kinds of throttle body’s
The one with electric motor against spring, i use pwm voltage / amps controlled
The ones with stepper motor, i use arduino and stepper controller.
You mentioned pwm controller for yours, can you post a picture and or the specs ?
With PWM you won’t damage the motor if you don’t exceed the amps for the motor coil
My Chevy TB is definitely the first, an electric motor against a spring. Here’s the exact pwm I used. It operated it without any noise or feedback sounds. It’s just very touchy because of the limited voltage range.
Found one of those cutout kits on eBay. Looks like it uses a momentary switch but the control box it comes with uses that momentary signal to fully open and close.
@k_vanlooken do you think the controller is merely a PWM or do you think it’s a polarity reversing box?
Hi Cody, to measure at 12 Volts and check how much milliamps it takes on certain degree of opening.
I guess its about 500 milliamps fully opened. However to check for your case
This 3" electric valve is with end switches, you could ignore them and make your own value , polarity reversing with an switch, 2 pole , 3 position, where as the middle position is “off”
Choose open or close depending any experience on sound/feels like or add an O2 sensor
Here’s another exhaust cutout, this one appears to be more simple. It has a return spring visibly shown and no big controller box, just a 3 wire switch that I’m assuming is momentary. I sent a message to the seller to ask if this can be more finely controlled or if it’s a simple Open/Close control.
This picture show’s the switch with 3 positions, the valve actuator have end switches, hence the 3 wire system.
For me i like the system with no internal switches, but that is my like…
I do experiment a lot, still have more things i would like to learn
Your TB are different than mine. Mine are out of a early 2000 civics. They require 12v to operate.(they are just a 12v motor) Off the top of my head i needed at least 9-10v to overcome the spring tention and get them to move. But controlling them with less than 12v will probably cause the windings to heat up especially since mine are set up to hold any position from 0-100% for an endless amount of time.
This is why i chose to go with an H bridge motor controller. This allowed me to drive the TBs with pwm at full power, using a pwm signal from the arduino.
You could easliy replace the arduino with your pwm to drive the H bridge.
To answer your question about replacing the pot…that will depend on how your pwm modual (circuit) is made. If for instance the pwm you have is using a voltage divider circuit (possably is) to a 555 chip or whatever, changing out the pot will change the output of the voltage divider but not nessesarly how you want.
If you can see the components on your pwm, you might be able to determin the output.
As for those exhaust valves, those are pretty cool. I wouldn’t mine playing around with them…but at those prices, ill stick with used TBs.
I am still very interested in the servo throttle bodies. If i had some of them, i could set up my system the same way i have it now but would be able to lose the H bridges. Any time another piece of hardware can be eliminated is a good thing.
I haven’t tried finding a make modle vehicle that uses them. But if i could pick some up for 15-20$ i would. @k_vanlooken what is the stepper motor TB out of?
Powering it up, movement isn’t engaged until about 2.2 Volts and the throttle is all the way open at 3 Volts. Going down to 2.2v doesn’t close the throttle however, I have to drop it below 1 volt to make it close.
Maybe it isn’t controlled via PWM? This is getting odd. You’d think that once you drop down to the voltage that began to move the butterfly, the return spring would do the rest.
That sounds really familiar to the way mine work. Due to the friction of the spring and all.
I am starting to think yours works the same as mine…just at a lower voltage.
Sounds like you need a motor driver, that way you can drive it at full power. So in your case 3v, but pwm to control the rotation.
How many wires are comming off your TB ?
Not sure what amprage your TB is drawing, i ended up using a L298n.
Mine has 6 pins, should be two position sensors and the motor. Reference voltage for the sensors is 5v but I think fully open is usually 4v, and the other sensor runs the opposite direction. I don’t know the exact layout, I just kept hooking my wires at different pins until I saw movement.
Hi Cody,
Depends on how and with what tool you measure.
The PWM gives out a voltage at a certain duty cycle ( pulses output vs pulses no output)
The voltage input of your PWM controller should be 12 VdC , similar as the car battery.
Then your pwm output should start with 5% and slowly increase the output duty cycle until fully opened.
Your PWM is advertised at 500 milliamps upwards to 2 amps.
Where as, depending brand and so on, the max amps for a normal TB is around 500 milliamps.
You might try with another PWM controller ?
I do have a second one for a cross reference but it is also rated at a 2A max. Maybe I should hunt down a 500ma PWM.
https://a.co/d/457STH6
I tried both supplying 12v and 5v, with 12v supplied it was even more touchy and only did anything in the low range. At 5v supply it was less touchy, but would only go down when I dropped voltage output below my starting point.
