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General Category => Your projects => Topic started by: GaMtnMan on September 28, 2014, 19:26:56 PM

Title: RC PWM conversion
Post by: GaMtnMan on September 28, 2014, 19:26:56 PM

I'm trying to accomplish something similar to the OP question but not as complicated.  I would like to use the PWM output of the R/C Rx to control two relays (or MOSFETS).  Basically I want to create a SPDT switch that reacts to the Forward-Neutral-Back position of the stick on the R/C Tx.  I know this would be easy to do using a PIC but I would have to get educated on PIC's before I could do that, which is a possibility but not my first choice.  I have a basic knowledge of electronics.

EDIT:  I think I found what I'm looking for...a low-pass filter with a window comparator circuit.  Still open for suggestions though.
Title: Re: RC PWM conversion
Post by: kam on October 01, 2014, 07:30:36 AM

Hello GaMtnMan,
Low pass filter is one solution although you have to make a very good filter with more than one stage.
I'd rather suggest a digital solution (Not with microcontroller). A clock feeds a counter for as long as the positive pulse is on. When the negative pulse of the PWM arrives, the counter resets. After taking a count (how long the duration is), then you have a digital comparator to compare the result.

Optimal solution is with a microcontroller though.