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.

Transformer Heating Problem

Status
Not open for further replies.
What are the transformers rated for?
 
See that the supply is actually around 230V. Though your drawing shows a rating of 200ma, you could be shorting it and drawing much more. Thirdly see the rating of ur transformer.
 
Your **broken link removed** needs to be rated at 1.6 to 1.8 times the DC load. Below is a chart from this web site.
 

Attachments

  • transformer rating1.PNG
    transformer rating1.PNG
    6.6 KB · Views: 196
Last edited:
I don’t know what is the meaning of “Transformer Rated for”. I just asked from the supplier give me a 6V/300mA full wave transformer & he gave.
& in the transformer it has printed 6V-0-6V 300mA only. Nothing else…My other transformers also printed in the same way.
 
Your capacitor looks upside down which means it could be drawing lots of current, but that might just be the way you have drawn it. The + must go to the diodes.

Transformer rating looks OK. Are you sure you are only taking 200mA?
 
Probably the core is getting saturated with magnetic flux for the amount of current you are drawing from the transformer.
 
What Ron H says is valid. In a powersupply with brute force filtering the average charging current for the filter capacitor is much higher than the average load current. This is one reason for the transformer to over heat.
 
Last edited:
k7elp60 said:
What Ron H says is valid. In a powersupply with brute force filtering the average charging current for the filter capacitor is much higher than the average load current. This is one reason for the transformer to over heat.
Here's a little "empirical" reinforcement (simulated):
Simulating Suraj143's circuit with the transformer, the rectifier, the capacitor, and a 200mA constant current load, I probed RMS current from the transformer.
With C=0, the RMS AC current was 200mA. No surprise.
With C=100uF (the ripple swings down to almost zero volts at the minima), the RMS AC current was 267mA.
With C=470uF, the RMS AC current was 410 mA. :eek:

No wonder his transformer is hot!
 
The peak voltage of the 6VAC is 8.5V. It has a load of 208mA so the power from the transformer is 8.5V x 208mA= 1.77W.
The transformer is rated for a max of 6V x 300mA= 1.8W.

It is operating very close to its max rating and it is probably a cheapo transformer.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top