[Collins] Transformers

[Dr. Gerald N. Johnson]

There are two inductances in the transformer equivalent circuit. 
Magnetization which is loaded by the secondary loads and leakage which 
is not coupled to the secondary. Leakage is responsible for much of the 
transformer impedance I discussed earlier, as much as 4% for a 
transformer wound on an E-I core. Resonating that with the series 
capacitor can get some odd results.

With a low impedance source, it doesn't take high Q to get a voltage 
rise. A Q of 2 (Xl = 2 R) is enough.

I have used the series capacitor to slow a fan and it worked for decades.

73, Jerry, Technical Adviser to the Collins Radio Association.

On 8/29/2013 7:18 PM, james.liles at comcast.net wrote:
> Hi Jerry:
>
> That would be true if there was almost no load at all because that would
> be the only time that the primary would display measureable inductive
> properties. If there is any load at all the capacitor would see
> resistive properties passed back from the secondary. The load that the
> filaments alone provide in a 100 watt radio with a 30uf series cap
> render the magnetizing inductive properties irrelevant. The first
> thought that comes to mind is the series resonance effect from the
> capacitor will cause catastrophic current in the primary. Not so. Try it
> it will be worth your time.
>
> Kindest regards Jim K9AXN
>
>