I need a transformer that can produce 10 volts from a 1/2 volt change in the primary winding, but don't know how they are classified. The transformers I've seen on the internet give no clue of the winding ratio, just a serial number. Thanks.
This is a voltage step up transformer. What is needed is winding turns ratio of 1 to 20. This means that for every turn of wire in the primary, the corresponding number of turn in the secondary is 20 thus if a voltage of one volt is applied in the primary, the output will be 20 volts. It should follow that if the input is 1/2 volt, the ouitput will be 10 volt.
Your question makes little sense as listed. Transformers are not usually used to amplify 1/2 volt variation. We need more detail.
I have never ordered a replacement transformer but you are looking to step the primary up 20 times and that is doable. I built a 1 Kilowatt amplifier for my ham radio station and my transformer steps the line voltage (either 120 or 240 volts) up to 3400 volts @ 500 mills. I also have a separate winding which steps the voltage down to about 9.6 volts for the tube filament. Aside from finding the correct step up ratio you also need to make sure the transformer can handle the power you will be dissipating. My transformer weighs about 25 pounds to allow the amp to put out about 1 KW. Wish I could've helped u more but I built the thing 15 years ago and have not fired up the amp in about 5 years.
A step-up transformer has a constant ratio of output to input voltage. So if you have a transformer that steps 110 volts up to 2200 volts, increasing the primary voltage to 110.5 will increase the secondary to 2210. I don't really think that's what you have in mind. If you are talking about amplifying a small audio signal, what you need would usually be called a coupling or interstage transformer. These would have the impedance in ohms listed in a catalog, and the impedance ratio would be approximately the square of the turns ratio. But I'm not sure this will do what you want, either. For instance, if you are trying to step up the voltage from a microphone or tuner to operate a speaker, the transformer alone won't do it--you need an amplifier. You probably need to resubmit your question, and specify what kind of a signal you are starting with, and what you want to do with it.
