Hi,
I am trying to design an ultra-simple DC-DC converter, and have developed the circuit below. By experimentation I have found that it works best when the transistor is driven with a 25kHz square wave, or 50kHz sine wave, at which point it will produce 30V @ 1mA, from a 1.5V battery.
The question now is, can anyone see a way of making this circuit self oscillate so I don't need a separate oscillator circuit?
(As usual, as soon as I actually want something to oscillate, it does its best to remain stable!)

 

Here's a simple self oscillating boost converter:
http://ludens.cl/Electron/ledlamp/ledlamp.html

You'd need to change some things to give you exactly what you want but it's a complete circuit at least.

 

You need to visit Ronald Dekker's page on flyback converters:
http://www.dos4ever.com/flyback/flyback.html

It's an excellent resource. Bookmark/Favorite that page.