inklen
Full Member level 1
Hello everybody!
I've recently (re-)started my journey in electronics. Last time I tried was very long time ago though. I started with books but not everything I read I understand.
So I started playing with an amp for a dynamic mic and then I read I could use a loudspeaker as a mic which is interesting to play with (as I have a pair of very old ones).
The circuit uses 8 Ohm loudspeaker and it's connected to a primary coil (Rp = 8 Ohm). The secondary coil "sees" TL082 (I haven't read much on op amps yet...) and it's set Rs=1kOhm for the secondary.
And here's where I'm confused. I to make this transformer myself, so I read everything it's available to me on this topic. The transformer is an audio step-up transformer. In this case, if this is an impedance matching then the turns ratio would be 11.
1) Correct me if I'm wrong on impedance matching. Or is this just for voltage (signal) step-up?
2) With turns ratio = 11 I can make 5/55 turns or I can make 50/550 turns. My understanding is if the inductance depends on L and dI/dt then I have to know an approximate dI/dt (current change rate). But how can I find this value? To measure from the loudspeaker?
If that's the case then I need to know the inductance and start from there - it's pretty easy to calculate number of turns then (considering material and core).
3) I want to make this transformer with a toroidal core. And I found the following core from Epcos with the following characteristics:
T38
T36
The optimum frequency range of T36 better suits the audio as far as I understand.
Overall, will such a toroidal transformer work in this case? Would it work with T38 (as I already have one)?
I've recently (re-)started my journey in electronics. Last time I tried was very long time ago though. I started with books but not everything I read I understand.
So I started playing with an amp for a dynamic mic and then I read I could use a loudspeaker as a mic which is interesting to play with (as I have a pair of very old ones).
The circuit uses 8 Ohm loudspeaker and it's connected to a primary coil (Rp = 8 Ohm). The secondary coil "sees" TL082 (I haven't read much on op amps yet...) and it's set Rs=1kOhm for the secondary.
And here's where I'm confused. I to make this transformer myself, so I read everything it's available to me on this topic. The transformer is an audio step-up transformer. In this case, if this is an impedance matching then the turns ratio would be 11.
1) Correct me if I'm wrong on impedance matching. Or is this just for voltage (signal) step-up?
2) With turns ratio = 11 I can make 5/55 turns or I can make 50/550 turns. My understanding is if the inductance depends on L and dI/dt then I have to know an approximate dI/dt (current change rate). But how can I find this value? To measure from the loudspeaker?
If that's the case then I need to know the inductance and start from there - it's pretty easy to calculate number of turns then (considering material and core).
3) I want to make this transformer with a toroidal core. And I found the following core from Epcos with the following characteristics:
T38
T36
The optimum frequency range of T36 better suits the audio as far as I understand.
Overall, will such a toroidal transformer work in this case? Would it work with T38 (as I already have one)?