Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Oscillator circuit operation in smps.

Status
Not open for further replies.

ArivNidunami

New Member
I am new in smps. I only want to understand how this circuit oscillating, especially the function of aux winding. Thanks.
IMG_3530.JPG
 
Last edited:
I'll take a shot at it. When power is applied, current flow through R2 & R3 into the base of T1 starts to turn it on. The collector of T1 goes low and current flows in the transformer primary winding. The aux winding is phased such that feedback through C2 turns T1 on harder. When the transformer saturates, the feedback collapses and the junction of R2/R3 is driven negative, turning T1 off. After the transformer field totally collapses, T1 is again turned partially on via the current from the supply through R2/R3 and the cycle repeats.
 
I'll take a shot at it. When power is applied, current flow through R2 & R3 into the base of T1 starts to turn it on. The collector of T1 goes low and current flows in the transformer primary winding. The aux winding is phased such that feedback through C2 turns T1 on harder. When the transformer saturates, the feedback collapses and the junction of R2/R3 is driven negative, turning T1 off. After the transformer field totally collapses, T1 is again turned partially on via the current from the supply through R2/R3 and the cycle repeats.

Thank you for your response. I draw a current flow with it, but i'm not sure.
Can you re-draw it? I know it will take more work, i really appreciate it. Thanks.
Untitled-2.png
Untitled-3.png
 
Last edited:
Loosely applied oscillation requires positive feedback and a gain of 1.
This is provided by the aux winding C2 and R3.
The operation is not unlike a blocking oscillator.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top