Electronic RC potentiometers (was R/C railroad locomotive?)

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

FBritt - 31 Dec 2003 00:36 GMT

Hi All,

Thanks for all the help with my RC locomotive project. I think I have pretty
well sorted things out with the exception of one control. I have found channel
controlled on/off and momentary on switches at Hobby-Lobby and EMS/Jomar. Now I
am looking for an electronic potentiometer to control the volume of my onboard
sound system (0 - 100). What can I use for that?

Regards,

Britt Harrington
Miami, Florida

Reply to this Message

Pete Christensen - 31 Dec 2003 01:11 GMT

I once hooked up a servo to control a potentiometer using linkage. Servo
turned the pot.

> Hi All,
>
[quoted text clipped - 8 lines]
> Britt Harrington
> Miami, Florida

Reply to this Message

Martin X. Moleski, SJ - 31 Dec 2003 01:18 GMT

>Thanks for all the help with my RC locomotive project. I think I have pretty
>well sorted things out with the exception of one control. I have found channel
>controlled on/off and momentary on switches at Hobby-Lobby and EMS/Jomar. Now I
>am looking for an electronic potentiometer to control the volume of my onboard
>sound system (0 - 100). What can I use for that?

There is a circuit used for electronic throttle control. I've been
thinking of adapting one of these for a smoke system. I saw
this on a video about Tournament of Champions, where Jason
Schulman used an Electronic Speed Control (ESC) slaved
to his throttle channel to slow down the smoke pump at low
throttle and speed it up at full throttle.

I don't know whether an ESC does the same thing as a
pot.

Marty

Reply to this Message

Doug McLaren - 31 Dec 2003 07:30 GMT

| I don't know whether an ESC does the same thing as a
| pot.

It does, and it doesn't.

A pot adjusts the current flow by introducing a variable resistance.

An ESC adjusts it by turning the circuit on and off a few thousand
times a second.

An ESC is more efficient -- no signifigant loss due to resistance,
where in the case of a pot, at low speeds most of your power goes to
heating the pot rather than running your load.

For a smoke system or a motor, I imagine an ESC would be by far the
best solution.

However, for an audio system, what it would probably do is introduce a
very loud noise of a few khz to the system -- I doubt it would work
well.

A mechanical speed control would work -- it's basically just a servo
that chooses between a few large (able to handle lots of current)
resistors. It wouldn't give you very fine control (probably only a
few settings) but it would be easy.

Probably the best solution is the one already given -- just have a
servo turn your pot.

Signature

Doug McLaren, dougmc@frenzy.com
You are sick, twisted and perverted. I like that in a person.

Reply to this Message

Model Forum / Radio Controlled / Air Models / December 2003

Electronic RC potentiometers (was R/C railroad locomotive?)