suitable oscillator circuit for dc to ac converter

[cocopa]

Hello, I'm designing a high voltage generator and I would like some suggestions.
The oscillator will take a dc voltage (maybe from a 9v battery) to produce ac, a transformer will boost the p-p output and then some voltage multipliers will produce the desired dc ouptut.
What type of oscillator circuit would be suitable?
The desired high voltage is about 500v and the current that the load will draw is very very small,some nanoAmperes only.
So i'd like the whole system to be as small (in size) as possible, draw as little current as possible from the battery and ofcourse at small cost!
Any suggestions on suitable oscillators circuits are welcome.

 

[crutschow]

What frequency of operation do you want?

 

[cocopa]

I don't have any restrictions on that.I just want to keep the size of capacitors,inductors and the transformer as small as possible.

 

[jcaram]

The higher the frequency, the smaller the transformer. It's easy to find transformers for audio frequencies and they can be tiny. Any oscillator would work, even something based on a 555 timer.

JP

 

[crutschow]

A 555 timer configured as an astable oscillator can provide the frequency you need.

 

[cocopa]

Hello again!I finally used a relaxation oscillator (which draws very little current) but i'm having troubles simulating the circuit.
When i simulate the oscillator circuit alone it works fine, but when i try to simulate it with the transformer and the voltage multipliers stages i get no oscillations.
If I add a series resistance at one end of the primary to ground,i get oscillations on the primary side but still nothing on the secondary side.
What could be the problem?What do i have to be aware of in order to retain the oscillations?