Go Back   DIY Go Kart Forum > Building Plans And Advice > Electric Projects

Notices

Closed Thread
 
Thread Tools Display Modes
  #1  
Old 01-26-2013, 06:54 AM
Bajamerc Bajamerc is offline
Junior Member
 
Join Date: Jan 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default slowing down response time for open loop

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.
  #2  
Old 01-26-2013, 07:07 AM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,202 Times in 1,692 Posts
Default

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...
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #3  
Old 01-26-2013, 07:24 AM
Bajamerc Bajamerc is offline
Junior Member
 
Join Date: Jan 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

hydro?
  #4  
Old 01-27-2013, 05:13 AM
Doc Sprocket's Avatar
Doc Sprocket Doc Sprocket is offline
*********
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 15,677
Thanks: 723
Thanked 2,202 Times in 1,692 Posts
Default

-Electric.
__________________
Treat it as you would an aircraft frame and you should have no problems. -Name Withheld
The Manual- "Just the manufacturer's opinion of how to put this together."- Tim "The Tool Man" Taylor
Put down the wrench, and come out with your hands up!- Me!
Wrench, Wheel, Wreck, Repeat...
  #5  
Old 01-27-2013, 08:58 AM
Bajamerc Bajamerc is offline
Junior Member
 
Join Date: Jan 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

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.
__________________
I hope you heard about that ornithological headline. It was regarding mass awareness of a certain avian variety.
  #6  
Old 01-27-2013, 10:46 AM
souperman000's Avatar
souperman000 souperman000 is offline
Senior Member
 
Join Date: Dec 2011
Location: Westlake Village, CA
Posts: 2,466
Thanks: 38
Thanked 224 Times in 212 Posts
Default

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.
__________________
It's hard to help people that won't help themselves.
  #7  
Old 02-03-2013, 01:10 PM
oscaryu1 oscaryu1 is offline
Senior Member
 
Join Date: Mar 2008
Posts: 2,767
Thanks: 6
Thanked 148 Times in 60 Posts
Default

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.
  #8  
Old 02-03-2013, 02:11 PM
Cjhoward78's Avatar
Cjhoward78 Cjhoward78 is offline
Senior Member
 
Join Date: Jan 2013
Posts: 112
Thanks: 1
Thanked 2 Times in 2 Posts
Default

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!!!
  #9  
Old 02-04-2013, 11:52 AM
Bajamerc Bajamerc is offline
Junior Member
 
Join Date: Jan 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

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/...7/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.
__________________
I hope you heard about that ornithological headline. It was regarding mass awareness of a certain avian variety.
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 11:31 AM.