Reducing Halloween Prop Jaw Servo Chatter

WPUser

Hi. I'm trying to figure out how I've managed to burn up two HITEC HS-225BB servos I'm using to drive the jaw in a DIY Halloween zombie.

I recorded my audio files using WavePad, and I copied them to an MP3 player board. The player's audio output is fed to a nifty ServoTalk device (made by frightideas.com) which processes the audio into a servo PWM signal. The ServoTalk also generates pseudo random servo signals for head and eye movement.

I'm observing a degee of chatter on the jaw movement (which I actually thought looked kinda cool on my Zombie), but not on the head or eye servos. I'm thinking that the jaw servo may be gradually burning itself up trying to respond to higher frequency (chatter) components of the ServoTalk output signal. I've no idea if the chatter is a component in my audio recording which the ServoTalk is simply passing along to its output, or if the ServoTalk is generating chatter on its jaw servo output in response to my audio recording. It's also possible that something about my circuit implementation (e.g. 8 foot long servo power lines) may be causing the chatter.

I'm curious if anyone knows how to filter a WavePad audio file such that an audio-to-jaw servo driver, like the ServoTalk, will not generate unrealistically high-frequency servo position changes in its output signal.

Thanks!

borate

The equalizer may be of use. Try the 'low pass' preset to suppress higher frequencies.

WPUser

Thanks for your suggestion, borate. I've been made aware that another person using audio-to-jaw-servo devices has also experienced chatter using the HS-225BB servo. If trying a different servo doesn't fix my problem, I'll try your equalizer suggestion.