slowing down response time for open loop

[Bajamerc]

Hi, I am Baja. I am new here.

I have two types of speed controllers to slow the response time for. I am trying to gain more control over restricting acceleration and deceleration.

First Case:

This speed controller sends a 5v feed to the input device. The input device then sends some portion of the voltage back to the controller based on how much the person squeezed it.

If a person hops on and gives it full throttle accidentally, how do I slowly ramp the speed up?
I was thinking I could use a capacitor to slow down the response times.
I am not sure what configuration I should do. (in series?)


Second Case:

This one uses a PWM signal. (pulse width modulated signal)
http://www.andymark.com/Talon-p/am-2268.htm is an example.
I believe that based on the time that the PWM is sending a 1 during the period determines the percentage of the power going to the motor.

Again I thought a capacitor would work, but I think the configuration is going to be pretty fancy.


For both cases I mentioned using capacitors. I think alternatively I could use an arduino. But I don't do much coding.

Any help is appreciated.

 

[Doc Sprocket]

Welcome to the forum! I'm just going to pop this over into the electrical section, hopefully the right folks will see it there. Be patient, though- there's a lot less hydro guys on here than dino guys...

 

[Bajamerc]

hydro?

 

[Doc Sprocket]

-Electric.

 

[Bajamerc]

I am so lost.

I was hoping to find out if putting the capacitor in series with the input device would slow the response time like I hope for the signal in the first case.

And I wanted to know how to slow the response of the pwm signal too.

 

[souperman000]

Toystory is saying that most of us on here work alot with gasoline engines, and aren't too familiar with electric motors. You just have to wait for the right guy to come around.

Hydro and dino are slang for electric and gas.

 

[oscaryu1]

You would put it in parallel. Issue is, when you left off, the residual charge in the capacitor would still need to discharge. You'd have "lag" when getting on the throttle, but there'd still be a pause before the controller cut power to the motor after you let off the throttle.

 

[Cjhoward78]

Could u use a relay and ground circuit to discharge ur cap when u come off throttle. Normally closed to ground then when on throttle open. Just a thought!!!

 

[Bajamerc]

I appreciate the help.

I got some help locally from a guy with a PHD in EE. I am putting the cap in series with the input device based on his recommendation for the 5 volt version.

Here is a link to some RC time constant calculations.

http://www.labsanywhere.net/circuit/lectures/lect7/lecture7.php

Oscaryu1, I am not worried about the residual voltage because I will have the cap after the input device in the line to the input of the speed controller. So the speed controller will linger both slowing down and speeding up to whatever arbitrary delay I am asked to set the time constant too.

This is for a senior design project, and I wondered if there was anything weird I needed to worry about because some of the ME instructors were telling me to use an arduino and program the delay for the 5v version.

I think I could understand the advantage to programming the pwm. I usually handle those in lab

The guy with the PHD I mentioned alleviated that concern for me. I also no longer need to worry about the pulse modulated system. It would be nice to know how to slow that response down. Or was that what Oscaryu1 was referring to when he said to put it in parallel. I couldn't tell which one you meant to put in parrallel.

ugh, gotta go, I had more to edit in this post as I left out some details. Just don't have the time right now. I did want to comment on the software that I normally deal with pwms in. Can't remember the name. I want to say labview, but not sure.