[SOLVED] Auto oscillating DC-DC converter

[ysba]

Hello,

I've stumbled with the circuit in the attached image.



It is a DC-DC converter which uses a small ferrite transformer, driver by two oscillating BJT. The output is then rectified to generate a DC output voltage. It is pretty simple, works just fine. The switching frequency is about 14 kHz and the output voltage follows the DC input voltage according to the turns ratio.

Does anyone know if this circuit has a specific name? Is there some paper or documentation that explains this circuit in detail?

Thanks.

Cheers,

Yuri

- - - Updated - - -

I think I got it:

https://davidcaudrey.me.uk/page8.html

"Saturating core DC-DC converter"

If anyone has some info to add it would be nice.

Thank you very much.

 

[FvM]

Usual names are self-oscillating push-pull converter or self-oscillating push-pull blocking oscillator.

 

[asdf44]

Also "Royer oscillator"

https://en.wikipedia.org/wiki/Royer_oscillator

 

[schmitt trigger]

These types of converters were once ubiquitous in compact cameras to transform the voltage from a pair of AA cells to the high voltage required by a xenon flash tube.

When you turned the flash on, one could hear the transformer whining.

Nowadays camera flashes are LED-based.

 

[asdf44]

I think its still common for small isolated DC-DC's like this 1W part:

https://www.digikey.com/product-det...ions-inc/NXE1S0505MC-R7/811-3040-1-ND/5047366