Idea 1of 4Builds onOnly change inducesThe push
Turns set the volts
Two coils on one iron ring. Volts out?
Today you'll discover
- how energy crosses between coils that never touch
- what the number of turns does to the volts
- the one fraction that sets the output
Think firstAC into one turn; twenty turns beside it
AC into a one-turn coil on an iron ring; a twenty-turn coil sits beside it. Volts out?
Decide first, then press Next. Count the turns on each side and compare the volts.
An iron ring with a one-turn coil on the left and a twenty-turn coil on the right. After a prediction, a dashed changing field appears in the core, then the secondary's turns are counted and its volts printed, twenty times the primary's. The last step turns it round, twenty turns in and one out, and asks the volts out.
See the whole ideathe big idea and the key word, in one place
The big idea
The turns ratio: twenty times the turns, twenty times the volts.
See the patternThe ratio is the whole rule: 1 : 20 gives twenty times the volts, 20 : 1 gives a twentieth. The field in the iron is the same for both.
Key word
- turns ratio
- the number of turns on the output coil over the number on the input coil; the output volts are the input volts times this ratio, Vs ÷ Vp = Ns ÷ Np
About this modelVs ÷ Vp = Ns ÷ Np, and Vp Ip = Vs Is: a lever, not an amplifier. AC only, because only change induces.
Vs ÷ Vp = Ns ÷ Np, and Vp Ip = Vs Is: a lever, not an amplifier. AC only, because only change induces.
Ready to use it?
- Find the output voltage of two coils on one core from the turns on each side.