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Old 09-22-2012, 05:59 PM   #4
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Originally Posted by hayofstacks View Post
Denny, I'm glad you jumped in. My dad is an electorics guru and was half the reason I tried it. He has an osciliscope, and told me that even newer digital servo's work the same. We have a couple of am servos and radio's from 1976 that we could try out on it.

I'll consult with him and see what he has to add.
Sounds good.
FYI, my testing of the servos in my stuff were connected to a circuit that allowed varying the voltage output from the receivers signal wire with a simple 1K potentiometer. That way, the driving signal can be varied from zero volts to the full output voltage of the receiver.

I used a PicChip to generate the servo signal. If your dad ever played with these PicChips, let me know, I can send the assembly file used for the project. What's needed is a Microchip Pickit3 and a PicChip Pic12F675 computer chip, both from The circuit for the servo driver consists of the 12F675, a resistor, a capacitor for the 5 volt source and nothing else except connectors. You can program and reprogram these chips some 10,000 times with the PicKit3 programmer, and run it right from your computer.

Take a look:

The Pic12F675's go for about a buck each. You will also require a Radio Shack perf board, #276-150. Let me know if you are interested, I can send photos and wiring diagrams, what little wiring is involved that is.

The whole thing was monitored with my scope. The only thing not tested was whether the servo had a minimum required voltage. But since some of the servo's I tested only required 0.7 volts pulse voltage, I assumed that the low signal level would always be zero volts.

Retired and the days are just too short, busier than ever!
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