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THE AM BULLETIN BOARD => Technical Forum => Topic started by: jimmy on February 16, 2018, 10:13:34 AM



Title: Bucking Transformer
Post by: jimmy on February 16, 2018, 10:13:34 AM
Would some please explain what this is, how it works, and when it would be used.
Thanks ,
Jimmy K5CSU


Title: Re: Bucking Transformer
Post by: w7fox on February 16, 2018, 06:01:05 PM
Suppose you wanted to run a 110 volt radio on 120 volts.  You could use a 10 volt transformer to reduce the line voltage by hooking up the 10 volt winding in series with the radio.  Be sure to check which way the 10 volt is hooked up because in boost mode, the radio will have 130 volts on it.  Make sure the 10 volt winding has enough amperage to feed the radio.  Good luck.

73,
Fox


Title: Re: Bucking Transformer
Post by: Opcom on February 17, 2018, 10:54:58 PM
I hope this schematic will help. The best thing, but not shown, might be a 10V transformer with a tap every 2V or so. A variac can also be added, and need be only very small compared to the 120V load current.





Title: Re: Bucking Transformer
Post by: Opcom on February 17, 2018, 11:18:13 PM
This spreadsheet may help you calculate what you want. It is oriented towards entering the data on any transformers on-hand to see if they will help or not. It also shows the transformer's full load primary current, for variac wishes.
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