I am trying to take first steps at designing a transformer for a Ribbon microphone.
To my best understanding i will have to use the EMF equation in order to calculate primary winding number.
The equation is asking for f "f be the supply frequency in Hz". Since I supply the transformer with an AC signal ranging from about 20hz to 20Mhz, i don't know how to currently populate the equation ?
If someone can clear that up it will be great !
Hi Tomer,
Firstly, if I understand your post correctly, the transformer frequency range would be 20Hz to 20kHz, rather than 20Mhz
You seem to be wondering which frequency to use for your transformer calculations when a range of frequencies is involved. The answer would be to choose the lowest frequency, but for high quality applications you would normally go to approximately half the lowest frequency. So, on that basis, you would design your transformer to handle 10Hz.
You would chose the primary inductance to support the lowest frequency and the highest required voltage so that the current flowing through the primary winding does not saturate the transformer core.
The high frequency performance of the transformer depends mainly on the winding method and wire type, because of the skin effect, leakage inductance, and stray capacitances. For this reason you will need bifiliar layered winding and litz wire.
Unless you are contemplating winding your own transformer for the experience, I would recommend that you simply buy a ready made transformer for this application, especially if you need high quality audio, because this is a specialist area.