Servo Pulse to voltage converter.. Mini SSC II

[Jon]

I have a motor that requires a control voltage between 0-5V.. Ov=stop
and 5V=full speed. I'm using Mini SSC IIa and need to take one of the
servo outputs and create a voltage?

Is there any off the shelf device that will do this?

Can I just integrate the pulses and offset and scale the integration
with an op amp circuit?

Thanks,
Jon

 

[Si Ballenger]

On 1 Feb 2005 11:16:25 -0800, "Jon" <jonspam@earthlink.net>
wrote:

I have a motor that requires a control voltage between 0-5V.. Ov=stop
and 5V=full speed. I'm using Mini SSC IIa and need to take one of the
servo outputs and create a voltage?

Is there any off the shelf device that will do this?

Can I just integrate the pulses and offset and scale the integration
with an op amp circuit?

Thanks,
Jon

I've tinkered with a kronosrobotics servo control chips and ran a
servo control output thru a diode to a 1mf capacitor. I was able
to connect this to the base of an NPN transisto to the + side of
the capacitor, which inturn controlled an LED. I could see some
change in led intensity when changing the servo position full
range. You can connect a meter and see some voltage change. Below
is a page where I'm using a mini ssc ii as a pan/tilt webcam
control.

http://www.geocities.com/zoomkat/ppswitcher-demo.htm

 

[Doug McLaren]

In article <1107285385.239668.184260@f14g2000cwb.googlegroups.com>,
Jon <jonspam@earthlink.net> wrote:

| I have a motor that requires a control voltage between 0-5V.. Ov=stop
| and 5V=full speed. I'm using Mini SSC IIa and need to take one of the
| servo outputs and create a voltage?
|
| Is there any off the shelf device that will do this?
|
| Can I just integrate the pulses and offset and scale the integration
| with an op amp circuit?

I'm not familiar with the Mini SSC IIa, but are the servo outputs it
generates compatible with R/C servos? Judging from this page --

http://www.seetron.com/ssc.htm

that's exactly what it's supposed to control.

If so, then all you need is a R/C ESC (electronic speed control) and
you're set. It doesn't really get any more `off the shelf' than that
-- the plug may even be the same.

ESCs don't generally vary the voltage. Instead what they do is turn
the power on and off a few thousand times a second, so 1/2 power =
power on 50% of the time, 25% = 25%, etc. This is more efficient than
other ways of adjusting the motor speed, and scales very well when
you're dealing with large motors (I know you're not, but ...)

Guessing that your motor is very small, something like this might be
perfect --

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXUR93&P=7

but there are other versions available, larger and smaller. Dozens,
possibly hundreds of other versions.

--
Doug McLaren, dougmc@frenzy.com
He who fights monsters should see to it that in the process he does
not become a monster." - Neitschze