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Ed_Dinning · 12th Sep 2017, 9:35 pm

Hi Andy, a nice solution using an autotransformer. I've made a few of these for people who needed to use CRT's with different heater voltages.

It will also work on AC/DC sets (but only on AC) provided the VA requirement for the 2 valves are approx. the same.

Turns a volt looks a bit high for that lam set, but the quick and dirty way to check is to plot a volt/ amp curve for say 100 turns wound on the former and look for the mid point of the "knee". That will give the t/v figure.
Depending on the wire used you may need to add compensating turns to the output winding.

Ed

12th Sep 2017, 9:35 pm	#3
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Cossor 54 4TP substitution Hi Andy, a nice solution using an autotransformer. I've made a few of these for people who needed to use CRT's with different heater voltages. It will also work on AC/DC sets (but only on AC) provided the VA requirement for the 2 valves are approx. the same. Turns a volt looks a bit high for that lam set, but the quick and dirty way to check is to plot a volt/ amp curve for say 100 turns wound on the former and look for the mid point of the "knee". That will give the t/v figure. Depending on the wire used you may need to add compensating turns to the output winding. Ed