Hobby Electronics Basics LC oscillator

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Subject Author Date
LC oscillator Ken 01-29-06
Posted by Ken on January 29, 2006, 3:14 am
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Hello,

I am looking to do a LC or bank oscillator. I searched the internet I have
not seen what I want.
I just wanted a simple oscillator and a power supply that would just keep
injecting the loss energy of the LC circuit. I have included a small
schematic, but it do not work in my pspice simulation

thanks in advance for your help

ken


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end


Posted by Dan Hollands on January 29, 2006, 10:44 am
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> Hello,
>
> I am looking to do a LC or bank oscillator. I searched the internet I have
> not seen what I want.
> I just wanted a simple oscillator and a power supply that would just keep
> injecting the loss energy of the LC circuit. I have included a small
> schematic, but it do not work in my pspice simulation
>
> thanks in advance for your help
>
> ken
>
>

Since the minus input of the opamp is tied to the plus rail, the output of
the opamp is going to be a fixed low dc level


--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606
dan.hollands@gmail.com
www.QuickScoreRace.com



Posted by POWERMOS on January 29, 2006, 11:06 am
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>
> > Hello,
> >
> > I am looking to do a LC or bank oscillator. I searched the internet I
have
> > not seen what I want.
> > I just wanted a simple oscillator and a power supply that would just
keep
> > injecting the loss energy of the LC circuit. I have included a small
> > schematic, but it do not work in my pspice simulation
> >
> > thanks in advance for your help
> >
> > ken

Could you please explain what you desire in a more deeply way?
LC oscillator may be of several type, the simplest topology you can build
they are Colpitts and Hartley, I've simulated this type of oscillator some
years ago with PSPice (Microsim release) without problem, just remember, in
order to keep oscillation starting you've to add some noise generator into
the oscillator loop (e.g. in series to one capacitors), a VPULSE sorce may
be good, just a single pulse to force the system to oscillate.

Cheers
Fabio



Posted by Ken on January 29, 2006, 9:07 am
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> Could you please explain what you desire in a more deeply way?
> LC oscillator may be of several type, the simplest topology you can build
> they are Colpitts and Hartley, I've simulated this type of oscillator some
> years ago with PSPice (Microsim release) without problem, just remember,
> in
> order to keep oscillation starting you've to add some noise generator into
> the oscillator loop (e.g. in series to one capacitors), a VPULSE sorce may
> be good, just a single pulse to force the system to oscillate.

Ok, well many circuit I have seen do not take advantage of the inductor
discharge, and keeps cherging the capacitor from empty. I would like in my
circuit to be able just to add the lost voltage to keep the oscillation
going. In my circuit when the voltage falls below a certain point, it
recharge the circuit.. but how do I know it is recharging the capacitor and
that it is not being sent when the capacitor has just finish discharging.
( I think that if the circuit sends power to the capacitor when it has just
discharge in the inductor, the frequency will jump a bit .. maybe I am
wrong..)

Ken



Posted by CWatters on January 29, 2006, 5:51 pm
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> Ok, well many circuit I have seen do not take advantage of the inductor
> discharge, and keeps cherging the capacitor from empty. I would like in my
> circuit to be able just to add the lost voltage to keep the oscillation
> going.

Not quite sure what you are trying to do but it sounds like you need to read
up on oscillator design.

What you are describing sounds very much like feedback...

http://www.answers.com/topic/positive-feedback



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