11-12-2021, 06:10 PM
(This post was last modified: 11-12-2021, 06:12 PM by Ed_Dinning.)
Hi Adrian, be careful studying Scroggie, it is good theory but he uses the imperial system of measurements that confuse the hell out of most people. (note that I'm perfectly happy with mechanical measurements but electrical units wind up with all sorts of strange constants.
The old transformers you are dealing with are most likely to be Stalloy, so operate at 1 Tesla or less.
T/V are inversely proportional to frequency, so use 2 times the turns that you would for 50Hz for the 25Hz frame rate.
The 4.44 constant is related to the Sine wave form factor (1.11) (1.0 for a square wave.)
As a first approximation the flyback is a small portion of the total cycle and is effectively an HF component, so ignore.
The above is an Engineering approach to get you close, not a detailed mathematical analysis, I leave that to others
If you can, use an autotransformer as that will reduce the size of wire and winding. This works well for ratios of about 1:1 to 3:1
Ed
The old transformers you are dealing with are most likely to be Stalloy, so operate at 1 Tesla or less.
T/V are inversely proportional to frequency, so use 2 times the turns that you would for 50Hz for the 25Hz frame rate.
The 4.44 constant is related to the Sine wave form factor (1.11) (1.0 for a square wave.)
As a first approximation the flyback is a small portion of the total cycle and is effectively an HF component, so ignore.
The above is an Engineering approach to get you close, not a detailed mathematical analysis, I leave that to others
If you can, use an autotransformer as that will reduce the size of wire and winding. This works well for ratios of about 1:1 to 3:1
Ed
