Need 4 ch transmitter schematic

Apr 01, 2004 7 Replies

I am relatively new to electronics, not dealt with digital circuitry so far, but eager to learn while building my own receiver, ESC's and transmitter for a rather complex project. The receiver I had very little trouble finding schematics for - a good looking ESC was even easier. But so far I have not seen any transmitter diagrams on the web. I would like a good four channel (at least) PWM transmitter (as this is the modulation the reciever and ESC's use), which is not powered by a programmable microprocessor. Any ideas, other than buying one (for money I could spend on steel)?



Elias


NOt using a microprocessor eh?

How much time and money do you want to spend with triangle generators and comparators and the like :-)

Or perhaps halfway house with up down counters and a few A to D convertors on the sticks?

Hi,

Perhaps this helps :

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Have also a long at Alan Tong's websit, possible you'll find more links :
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: directory to 000's of Radio Control Aircraft, Yachts, Boats, Cars, Plastic and Resin Kitset modelling web sites. Many RC FAQ, Modelling and RC Construction articles, Model and RC related Manufacturers and Retailers sites. "

Olivier

TNP, I think you are old enough to know better than what you said about " triangle generators and comparators and the like" or " Or perhaps halfway house with up down counters and a few A to D convertors on the sticks?"

The 1970 Heathkit GD-19 I built had a 2 transistor multivibrator to generate the frame rate, and each channel pulse was generated by simple R-C circuit >Elias wrote:

Eh? what do you think a one shot multivibrator is if not a triangle generator and a comparator...you just have to look at the internal waveforms and see...

As far as teh updown counters go, its a perfectly valid way to do it, and would be fairly simple to implement in the sort of SSI logic which is more or less all we had in the 70's.

But when you can get a PIC with A to D and all teh logic needed on it for $2.50 or wahtever, its seems strange to use teh analog route.

Well, Building and understanding Tx/Rx gear is also a funny part of our hobby. Period. But be aware that you MUST stick to your local regulations for RF radiation and accreditation. Ignoring that can lead to big, really very big problems that could include your responsability for injury or death. Disturbing an emergency service is not a joke. Loss of control from a homebuild gear not more. Knowing that you may want to make a Google search on "signetics NE5044" to learn encoder and try to have RF section from another source. You can also approach Ham-radio clubs. It's up to you. One source is to buy some used Tx in your local hobby shop or club. I still think that the best way is to buy approved basic Tx/Rx gear (really not expensive)and take time for the real project.

Have fun,Fly safely Daniel

Cheers mate! I'll just email you my home address, and you can buy, program and FedEX me those PIC's - free of charge, right? :D

As I don't own a PIC programmer myself, and I wouldn't know how to use one, I'd say my best shot would be to build me one of those expensive, inaccurate, bulky, prehistoric analogue transmitters using previous century technology. So if you're not interested in sending me those microprocessors, maybe you are in possession of a diagram of an old kickass transmitter, hm? :)

Thank you, Olivier, for those links. Provided I am given the sufficient time to go through it all, I am sure I'll find something useful. :)

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