Could anyone advise me on what transformer is used to power this circuit; where maybe sourced etc, I am in uk , thanks in advance.

Mod: link to old thread.
https://forum.allaboutcircuits.com/...er-supply-troubleshooting.171003/post-1527510

 

Welcome to AAC.

To meet spec (such as they are) you'll need 28 or 30v ac or 15-0-15v ac secondary, 90-100VA ('100W') rated. You can get them on eBay for around £60.

Farnell have a 100va 30v ac x 2 toroidal transformer for £61 (part # 4209595 )

But why? This is an old and problematic design.

 

I wouldn't use the maximum rated voltage/current transformer with these boards. They are overrated of course.
At less, they work fine, given the price of the kit (all parts and PCB) can go for $5. Just need to add transformer, heatsink/fan etc.
A 25VAC transformer at 50VA might be a better power rating, or a hi/low switch.

edit: TL081 max. is 36V rail with gives around 27VAC max.

 

Welcome to AAC.

To meet spec (such as they are) you'll need 28 or 30v ac or 15-0-15v ac secondary, 90-100VA ('100W') rated. You can get them on eBay for around £60.

Farnell have a 100va 30v ac x 2 toroidal transformer for £61 (part # 4209595 )

But why? This is an old and problematic design.

Thank you,starting electronics after 35 year layoff, I think this ideal to play around with,

I wouldn't use the maximum rated voltage/current transformer with these boards. They are overrated of course.
At less, they work fine, given the price of the kit (all parts and PCB) can go for $5. Just need to add transformer, heatsink/fan etc.
A 25VAC transformer at 50VA might be a better power rating, or a hi/low switch.

edit: TL081 max. is 36V rail with gives around 27VAC max.

thanks I’ll try that..

 

After 46 years, that circuit has not been beaten, in terms of simplicity and cost. The original design I trace back to Practical Electronics Oct. 1978 pg. 40. I know it's not a perfect power supply board but is "good enough" for many applications and china offers the copy for dirt cheap.
That original article might help with your build - but keep in mind the chinese kit uses newer IC's (TL081 verses LM741) that can't quite take as much voltage, so the transformer should be at most around 25VAC IMHO. The original article recommends a 20-25VAC, 2A transformer (based on the pass transistor's limits).

 

After 46 years, that circuit has not been beaten, in terms of simplicity and cost. The original design I trace back to Practical Electronics Oct. 1978 pg. 40. I know it's not a perfect power supply board but is "good enough" for many applications and china offers the copy for dirt cheap.
That original article might help with your build - but keep in mind the chinese kit uses newer IC's (TL081 verses LM741) that can't quite take as much voltage, so the transformer should be at most around 25VAC IMHO. The original article recommends a 20-25VAC, 2A transformer (based on the pass transistor's limits).

Thank you, my ideas are to play around with that board, to help me get back into electronics.