From +12V to +300V, I can not get it

[EEHobby]

Attached image is my design. It is based on the following link
**broken link removed**

The componet I used is

Transformer: data sheet is below

**broken link removed**

Transisitor : MJE3055. The data sheet is
https://www.onsemi.com/pub/Collateral/MJE2955T-D.PDF

But no way can I get 300V. Any boby can tell me what's wrong? Thanks a lot.

[/img]

 

[e_eja]

But no way can I get 300V

is your primery oscillator working ? try measure using oscilloscope and carefully examine the waveform.

 

[EEHobby]

No. The primary oscillator does not work. For the two transistor, Q10 and Q11, sometime the collector of Q10 is 12V, the collector of Q11 is 0v when I power on. some times the other way, but I did not see any oscillation.

 

[IanP]

This circuit, as it is, will not work ..
Try to add some components around both transistors .. see picture below ..
http://www.i4at.org/lib2/inverter.htm

Regards,
IanP

 

[EEHobby]

Thanks for your help. I am going to add the components you recommended. The only thing I am concerned is the efficiency. I am using 300V to charge a capacitor. When it is trigged, the capacitor will discharge and excite a transducer. So I don't really need high current. This is going to be used in a portable instrument powered by battery. Is this circuit very efficient? Can I still use MJE3055 instead of 2N3055? Once again, thanks for your help

 

[IanP]

Anything with 3055 will do ..

As far as efficiency is concerned, this configuration "looses" quite a lot of power (as heat) in the base resistors ..
If you can, change the concept and use MOSFETS with a small square wave generator .. see picture below ..
**broken link removed**

Regards,
IanP