Building a Colpitts

[ciscorey]

Hey guys, when it comes to EE I am the epitome of a novice. In fact, I picked myself up a experiment lab from Radioshack the other day to learn some basics. Unfortunately the superiors at work need me to develop a colpitts oscillator that oscillates at 13.46MHz. I was wondering if anyone had any pointers. I'm most confused about which components are necessary to acheive this result.

Thanks in advance.

 

[richs]

Hiya-

ARRL handbook will go into detail. Available from any library.

Computer guys (confuser) guys designing a colpitts oscillators. Scary stuff! Hope that Fox Charlie Charlie will not get involved with this!

 

[MacGyverS2000]

Your job is asking a non-EE to design an oscillator? For what purpose, personal amusement?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

There's more than enough info on the web to get you into trouble:

http://www.google.com/search?q=colpitts+oscillator

 

[ciscorey]

My boss is a bit of an inventor/entrepreneur. He's pretty successful at what he does. Now-a-days he's leaning towards achieving efficient over unity. This oscillator is necessary for the project we're working on.

Unfortunately, considering how most physicist feel about the theory of over unity and how it plays into our current understanding of the science, he refuses to invest in seasoned veterans. Furthermore, I doubt he wants to employ an EE for the sake of building one oscillator.

So now I have been burdened with the task of building it, lol. How fortunate (sarcasm).

 

[VEBill]

Over unity resides at 13.46 MHz - who knew?

;-)

 

[IRstuff]

http://en.wikipedia.org/wiki/Colpitts_oscillator

But why a Colpitts? You've identified effectively 100 ppm accuracy, which would take some doing with any analog approach.

TTFN

FAQ731-376

 

[VEBill]

I'd assumed an xtal would be used.

 

[ciscorey]

Well... this is more along the lines of WTP than it is OU. We're following the MIT model. Sorry for the confusion.

 

[MacGyverS2000]

A crystal, a schmitt trigger, some caps, a resistor, and a voltage source... that should about do it.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[ciscorey]

Thanks macgyvers. I mean, I managed to get a general schematic for the Colpitts oscillator. I was hoping I could get some detailed specs on each component without having to work out the frequency/LC equation. Looks like I may have to do it anyway.

I'm off to borders to pick up an ARRL handbook for further reference. Thanks for the help guys.

 

[MacGyverS2000]

Another suggestion... look at the clock section for a lot of the smaller micro-controllers out there. they typically have some useful component values, and the tech notes from the same companies will also have useful app details. These would at least give you useful starting values for 2/3rds of the components.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

My 1989 ARRL handbook (page 10-1) has a schematic of a Colpitts oscillator that uses a xtal and a 2N2222 and all the other components (R and C) are not frequency critical.

I obviously don't know all of your requirements, but it is not likely that you want an LC-based oscillator.

 

[ciscorey]

Oh, well Borders didn't have any ARRL handbooks in stock so I put one in order. I guess I'll wait for that to come in at the end of the week.

VE1BLL, is that so? My understanding of all Colpitts oscillators is that a few of their components' values are frequency dependant (especially the capictors). Then again, I know the least bit about electronics. But that's what I gathered from Wiki.

In either case, I'll try to work out the equation featured on Wiki and see what I come up with. Overwhelming still, It's been years since I've touched Mathematics. I appreciate all the help.

 

[melone]

While I'm not trying to discourge you from learning, why would you even entertain the notion of continuing with this project? Over-Unity machine! This is an exercise in futility. Perhaps, you should show your boss a book on physics, and try to explain why this hair-brained scheme will never work.

 

[VEBill]

Well, the Xtal is certainly frequency critical. Hopefully it has "13.46 MHz" stamped into or inked onto the package.

 

[ciscorey]

Well, it's not discouraging at all. Quite frankly, it's a matter of getting paid or not getting paid. The boss asks for it, I try to do it--whether possible or not.

Ironically, he actually owns a few books on Physics. And he understands the complications that are present when taking the fundamental laws of thermodynamics into consideration. But along with Tesla, hundreds of experimentors who have made positive claims of small scale success, and the mysterious Steven Marks, my boss is quite the believer of free energy.

I guess I can't knock him--considering that some of our greatest revolutions were sparked by radical, non-traditional concepts. But as stated before, I'm just a pair of hands looking forward to pay-day Fridays.

 

[itsmoked]

Most curious...
Save your money as your boss's will surely run out eventually. Or he'll land in prison for trying to sell some over-unity crap to some gullible mark.

Does sound like you have an interesting job though.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[MacGyverS2000]

huh, thought the "over-unity" thing was a joke... didn't realize the main in charge was actually asking for something real.

My suggestion, then, would be put down the soldering iron and start searching for another job... your current one is bound to run out of money in short order (assuming the company is based on these over-unity type schemes).


Dan - Owner

http://www.Hi-TecDesigns.com

 

[ciscorey]

lol...

Our revenue comes in from the other businesses he owns as well as a few of the patents he holds. For the obvious sensitivity issues of his projects, I'll spare throwing his name around--but rest assured, funding is not of major concern to him.

I really don't mean to spark debate of any sort. Perhaps he is nothing more than some looney, wealthy fool. Nonetheless, I find my work with him to be rather interesting and fruitful noless.

All the help is appreciated. And should anyone truly be interested in the OU debate, I'm definitely no legitimate candidate for or against the argument. But head over to overunity.com. There's some pretty interesting stuff going on in those forums.

Thanks again.