Voltage Doubling Circuit

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

Post Reply
User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

Voltage Doubling Circuit

Post by jon »

When you use a voltage doubling circuit, don't you loose half of you current capacity? I've been looking at some Marshall 100W iron and they all seem to be a little low on the current ratings, like 300mA. Factoring in the loss from the doubling circuit that would leave about 150mA, obviously not enough. Does the fact that the Marshall PT has a center tap change the rules?
User avatar
ToneMerc
Posts: 3480
Joined: Sun Apr 26, 2009 3:55 pm
Location: East Coast

Re: Voltage Doubling Circuit

Post by ToneMerc »

The voltage doubling trannies have a higher current spec. I just weighed a 1203-80 100W PT and it is almost 12.5 lbs. IIRC, it's current rating is in the range of 400-450mA. In addition the high tap of my MusicMan PT is rated at 268V @1A and it's putting out around 725V on the plates.

TM
paulster
Posts: 1299
Joined: Tue Oct 10, 2006 5:08 pm
Location: Los Angeles & London

Re: Voltage Doubling Circuit

Post by paulster »

On a tranny designed to be used with a bridge rectifier (let's drop this voltage doubler notion - it's not) the rating will be for the whole secondary winding.

Transformers designed with full wave rectifiers in mind will often be rated for only one secondary half pulling current at any time, i.e. on a 50% duty cycle and you therefore can't get away with pulling full current through both halves on the secondary if using it in a bridge rectifier configuration as you've increased the duty cycle to 100%.
User avatar
FYL
Posts: 654
Joined: Fri Feb 17, 2006 1:05 am

Re: Voltage Doubling Circuit

Post by FYL »

Does the fact that the Marshall PT has a center tap change the rules?
Yes. Check Delon doubler for more info.
Post Reply