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I need a very loud (120 dB) "buzzer" for high power rocket recovery.
I found a circuit on the web for a Piezo driver. From what I understand, The circuit is a CMOS buffer arrangement into an oscillator (about 3kHz), driving a step up transformer, feeding the Piezo speaker. I am looking for a 1:10 step up transformer (Secondary 200 mH) for the circuit.
Looking on the web, I was not able to find a 200mH inductor (I was hoping to hack this into the transformer I need).
1st question: Does someone know of a source for a 200mH toroid inductor?
Barring that I thought I would try to wind my own:
I did find some sources of Ferrite toroids (FT50-J), (Universal Radio) with a material ("J" material) that would take only a few hundred turns to make up the 200 mH I need:
N = 1000 * √([inductance needed]/Aj)
For the "J" material, Aj = 2710, n ~= 271 turns.
Assuming my theory is somewhat correct, I need some practical advice.
I selected the FT50 size to keep the overall size manageable, and was thinking of using 30 AWG wire wrap wire for the conductor.
I do not have an idea how to wind the toroid (in a practical way).
I have seen thin, long shuttles small enough to pass through the toroid, holding the conductor. The problem I foresee is the 30 AWB wire will fill up the FT50 pretty quickly (will it even fit?), not allowing room for a shuttle to pass.
I do have some fine "bell wire" 134-AWN, but I do not know how much current it can handle.
2nd question: Does anyone have any experience hand winding a toroid transformer?
3rd question: I am not familiar with the wire size 134-AWN; how much current could I manage if I ended up winding the transformer with this wire?
Thank you in advance for your help.
David W. Space Coast, Florida
I found a circuit on the web for a Piezo driver. From what I understand, The circuit is a CMOS buffer arrangement into an oscillator (about 3kHz), driving a step up transformer, feeding the Piezo speaker. I am looking for a 1:10 step up transformer (Secondary 200 mH) for the circuit.
Looking on the web, I was not able to find a 200mH inductor (I was hoping to hack this into the transformer I need).
1st question: Does someone know of a source for a 200mH toroid inductor?
Barring that I thought I would try to wind my own:
I did find some sources of Ferrite toroids (FT50-J), (Universal Radio) with a material ("J" material) that would take only a few hundred turns to make up the 200 mH I need:
N = 1000 * √([inductance needed]/Aj)
For the "J" material, Aj = 2710, n ~= 271 turns.
Assuming my theory is somewhat correct, I need some practical advice.
I selected the FT50 size to keep the overall size manageable, and was thinking of using 30 AWG wire wrap wire for the conductor.
I do not have an idea how to wind the toroid (in a practical way).
I have seen thin, long shuttles small enough to pass through the toroid, holding the conductor. The problem I foresee is the 30 AWB wire will fill up the FT50 pretty quickly (will it even fit?), not allowing room for a shuttle to pass.
I do have some fine "bell wire" 134-AWN, but I do not know how much current it can handle.
2nd question: Does anyone have any experience hand winding a toroid transformer?
3rd question: I am not familiar with the wire size 134-AWN; how much current could I manage if I ended up winding the transformer with this wire?
Thank you in advance for your help.
David W. Space Coast, Florida