Secondary voltage on transformer

AI Thread Summary
A transformer with a primary voltage of 120V AC and a turns ratio of 5:1 means the primary winding has five times more turns than the secondary. This configuration results in a secondary voltage of 24V when 120V is applied to the primary. If the transformer is connected in reverse, applying 120V to the secondary could yield 600V on the primary. However, the primary winding must have sufficient inductance to prevent excessive current, which could damage the transformer. For small transformers, a guideline is to have about five turns of wire for each volt applied.
bwd111
Messages
6
Reaction score
0
120 v ac primary and turn ratio of 5:1 I came up with 600v ac is this wrong
 
Engineering news on Phys.org
Which is the 5 and which is the 1?
 
5:1 ratio on secondary 120v ac primary x5 /5 = 24v secondary
 
Sorry, I don't understand. Is your question answered? If so, great. If not, I still don't know whether the primary has 5X more turns than the secondary or vice-versa.
 
If you had a transformer which had two windings with a turns ratio of 5 times as many turns on one winding as the other, and you connected 120 volts across the larger winding, you could get 24 volts across the smaller winding.

If you connected them the other way around, you might get 600 volts.

A complication you need to know about is that the winding with 120 volts across it needs to have enough inductance to stop a large current flowing in that winding.
Otherwise, the transformer could be destroyed.
A rough guide for small transformers is that there should be about 5 turns of wire for each volt put across the winding.

So you can't just have 5 turns and 1 turn and have it work at 120 volts.
 
Last edited:
I used to be an HVAC technician. One time I had a service call in which there was no power to the thermostat. The thermostat did not have power because the fuse in the air handler was blown. The fuse in the air handler was blown because there was a low voltage short. The rubber coating on one of the thermostat wires was chewed off by a rodent. The exposed metal in the thermostat wire was touching the metal cabinet of the air handler. This was a low voltage short. This low voltage...
Hey guys. I have a question related to electricity and alternating current. Say an alien fictional society developed electricity, and settled on a standard like 73V AC current at 46 Hz. How would appliances be designed, and what impact would the lower frequency and voltage have on transformers, wiring, TVs, computers, LEDs, motors, and heating, assuming the laws of physics and technology are the same as on Earth?
Thread 'How Does Jaguar's 1980s V12 Dual Coil Ignition System Enhance Spark Strength?'
I have come across a dual coil ignition system as used by Jaguar on their V12 in the 1980's. It uses two ignition coils with their primary windings wired in parallel. The primary coil has its secondary winding wired to the distributor and then to the spark plugs as is standard practice. However, the auxiliary coil has it secondary winding output sealed off. The purpose of the system was to provide a stronger spark to the plugs, always a difficult task with the very short dwell time of a...
Back
Top