Switching amp without any active components

[hairylee]

A while ago I came across an article in Electronics Weekly (I think) that had an old design for a switching amplifier. This design containd no transistors or active devices, just diodes, caps and transformer. Does anyone else recall seeing this and do they still have a copy of the design?

[Pano]

I'd love to see that! How do you do gain without active components? A transformer can do voltage gain, but you give up current.

Sure hope someone finds this novel idea.

[phase_accurate]

I wonder what month it was published (the year doesn't matter)! Could it be around springtime (northern hemisphere) ?

Regards

Charles

[pinkmouse]

This could be a possibility, but I suspect that Charles is more likely to be correct.

[hairylee]

After much searching around I found it by accident/luck whatever.. Here is a link. It wasn't in Electronics weekly afterall....
http://www.elecdesign.com/Articles/P...ArticleID=3979

[djQUAN]

I have also seen that in an electronics mag (1960's) and it showed a different schem but the same 4 layer diodes are used.

I remember it uses an input and output transformer and said it can be scaled up to 1kW.

[phase_accurate]

Aaaaaaah FOUR LAYER diodes !!! These ARE active devices IMHO.
This is an interesting circuit from the technical point of view. From the perfomance- and economical- points of view it isn't, unfortunately.

Regards

Charles

[theAnonymous1]

Are those 130v rails I see?

[Pano]

Clever stuff!

Pink Mouse, thanks for the link to the Mag-Amps. Had forgotten about those. I've seen the circuit used for dimmers. Big iron!