Hobbyist Question !

Thread Starter

Electric Al

Joined Nov 6, 2013
55
I have a power supply (salvaged from a boom box) .

The power supply works fine , and my output voltage is 9 volts D C .

Without changing any of the components , can I change the connection of the secondary of the transformer , to get 18 volts D C as my output voltage ?

The secondary of the transformer has taps which are not in present use .

I think I can , but I do not know what it might do to the other components .

Help please !

This may sound like a dumb question !
 

wayneh

Joined Sep 9, 2010
17,493
Try probing the other terminals, to see what voltages are there. Without more details, it's impossible to speculate. Try posting a photo. Maybe someone will see something useful.
 

Thread Starter

Electric Al

Joined Nov 6, 2013
55
Try probing the other terminals, to see what voltages are there. Without more details, it's impossible to speculate. Try posting a photo. Maybe someone will see something useful.

I just took another look at the power supply , and realised there are no other terminals on the secondary .

So I have only 9 volts secondary.

I may try to replace the transformer ( I have a few ).

Is this wise ?
 

w2aew

Joined Jan 3, 2012
219
Haha, well the devil is in the details. It's unwise to use the wrong replacement, but as long as the replacement meets the voltage and current rating of the original, it should be fine.
This will only work if the original is unregulated. If there is a voltage regulator following the transformer and rectifier, then increasing the AC secondary voltage will not change the output voltage (it will just cause the regulator to get warmer).
 

tubeguy

Joined Nov 3, 2012
1,157
I have a power supply (salvaged from a boom box) .

The power supply works fine , and my output voltage is 9 volts D C .

Without changing any of the components , can I change the connection of the secondary of the transformer , to get 18 volts D C as my output voltage ?
....
I just took another look at the power supply, and realised there are no other terminals on the secondary .

So I have only 9 volts secondary.

I may try to replace the transformer ( I have a few ).

Is this wise ?
If you are thinking of trying a higher voltage transformer, make sure the existing filter caps can handle the higher voltage. And, as mentioned, is there a voltage regulator in the existing supply?
 
Last edited:

wayneh

Joined Sep 9, 2010
17,493
I was only addressing replacing the transformer with a similar one.

There's not enough information to know if doubling the voltage is an option. Tubeguy and w2aew raise good issues.
 
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