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# Transformer Winding QuizDecember 1964 Popular Electronics

 December 1964 Popular Electronics Table of Contents Wax nostalgic about and learn from the history of early electronics. See articles from Popular Electronics, published October 1954 - April 1985. All copyrights are hereby acknowledged.

Popular Electronics magazine's quizmaster Robert P. Balin has created a new quiz entitled "Transformer Winding Quiz" for the December 1964 issue. It is one of more than 140 which I have posted thus far from issues of vintage electronics magazines, and some are ones I created myself. In the era this quiz was made, transformers were present in nearly every electronic product so understanding how primary and secondary (and tertiary, quaternary, quinary, senary, septenary, octonary, nonary, denary...) windings interacted for producing voltages, currents, and powers was essential. Whether the power source was AC or DC, a transformer was usually needed to supply high voltage vacuum tube plate biases, 6.3 volt and/or 12.6 volt tube heater supplies, and various other voltages. Careful attention to the phasing dots is required to figure out whether individual winding voltage should be added or subtracted from each other to get the net output voltage between a set of windings. After messing up the first one, I realized what I was doing wrong, then got the rest OK. Bon chance!

Transformer Winding Quiz

By Robert P. Balin

The same transformer is employed in each circuit on this page but the windings are connected differently to provide a variety of output voltages. In every case the primary winding and input voltage is 117 volts. Secondary windings are: 5 volts, 6.3 volts, and 250 volts center-tapped. The dots indicate the relative polarity of the windings. By carefully observing the additive or the subtractive effects of the windings it is possible to calculate the output voltage of each circuit. Can you?

1 ________             5 ________

2 ________             6 ________

3 ________             7 ________

4 ________             8 ________

Quizzes from vintage electronics magazines such as Popular Electronics, Electronics-World, QST, and Radio News were published over the years - some really simple and others not so simple. Robert P. Balin created most of the quizzes for Popular Electronics. This is a listing of all I have posted thus far.

1)  365.7 volts

2)  9.3 volts

3)  243.3 volts

4)  144.3 volts

5)  355.7 volts

6)  6.7 volts

7)  253.3 volts

8)  121.7 volts

Posted July 29, 2022