[Moved]diodes are getting damaged continuously

[rajaram04]

Hello sir
Im using a a centre tapped transformer outputs of 4.5 volts & 6 volts half half both the sides & an earth point.it means total 5 points at the output.it has 250 ma current statistics
Now i connect two diodes IN4007 for 6 volts supply so as to get proper rectifications & a 1000nf 16v cap. for proper filtration to a reasonable limit.
The problem is after using it in 3 to 4 days one of the dioides or both of them is getting damaged everytym
What would it be the reason behind it ? am i susing a wrong or low value or something else ?

 

[Aniruddh Sharma]

As per the application the diode selection is OK.
It will be helpful for us to understand your problem and provide the solution if you share the schematic

 

[zuisti]

If your transformer is strong enough, a too large peak current is possible at power on (when the filter capacitor (1000 uF and not 1000 nF, right?) is empty yet, so you can easily exceed the max. allowable peak current of the diodes.

One possible solution:
use a few (2-3) ohm resistor in series with the diodes.
or (using only one resistor):
(common point of the coils) ---- (2-3 Ohm) ---- (ground)

The power of the resistor(s) must be min. 0.5 Watt

 

[FvM]

so you can easily exceed the max. allowable peak current of the diodes

Not easily and not at all with a 250 mA rated transformer. Single cycle peak current of 1N400x is 30 A, by the way.

 

[rajaram04]

hmm okk i connected as per your sugesstion . Now have to watch out the result for some period.well thanks a lot once again.I n next reply i ll send you the diagram czuse i ve to make it properly on photoshop sir thanks once again let me watch it . .

 

[godfreyl]

i ll send you the diagram czuse i ve to make it properly on photoshop

MS Paint is easier. If you draw in black and white, and save it as a GIF, the file size is nice and small too.

 

[rajaram04]

sir here is the circuit diagram for centre tap transformer