Re: Choosing RC Servo Controller

rgagarrett@xxxxxxxxx wrote:

The valve is moved with an RC servo
motor. The motor drive electronics includes some 0-5V digital IO
lines, but they're not suitable for creating the PPM signal required
for the servo motor.

Do you mean a PWM signal? PPM signals are used for remote controls for RC
models, but a RC servo motor usually is controlled with a PWM signal, like
described in the other posting and which you can see here:

http://www.mp.ttu.ee/risto/rc/electronics/radio/signal.htm

In the light of the responses here I think the easiest thing for me to
do is to build my own controller using a 555 chip which I can control
via the IO lines. I know this should be straight forward, but I
didn't know whether there was a controller board already out there
that does what I want.

If you need two different pulse widths, which you can switch with a digital
signal, I would use a microcontroller, e.g. the PIC12F508, which you can
buy for $1.25. The program is about 100 lines of assembler, including
comments and the output pulse can be adjusted with 64 us resolution:

http://www.frank-buss.de/PICDigitalServo/index.html

--
Frank Buss, fb@xxxxxxxxxxxxx
http://www.frank-buss.de, http://www.it4-systems.de
.

Relevant Pages

  • Re: Choosing RC Servo Controller
    ... The motor drive electronics includes some 0-5V digital IO ... PPM signals are used for remote controls for RC ... do is to build my own controller using a 555 chip which I can control ...
    (sci.electronics.design)
  • Re: Simple mosfet question
    ... I am just intercepting the signal and ... Servo motor or something like ... Gate resistors help but it all depends on the energy and persistence ... Talk of motors and intercepting signals (one presumes that the signal ...
    (sci.electronics.design)
  • Re: LED Traffic light flash
    ... it is the controller which dims the intersection. ... > a method of dimming the intersection really does a number on the NEMA ... but all the lights can be seen on the intersection. ... LED signals regulate the current through the LEDs so that they can ...
    (sci.electronics.design)
  • Re: Welding -- what to do about HUGE 2" arcs
    ... controller which wants a DC voltage limit signal, ... when current is above some threshold, in the same analog computer ... You need to get those voltage and current signals properly scaled, ...
    (sci.electronics.design)
  • Re: Welding -- what to do about HUGE 2" arcs
    ... controller which wants a DC voltage limit signal, ... when current is above some threshold, in the same analog computer ... You need to get those voltage and current signals properly scaled, ...
    (sci.electronics.design)