View single post by sparks
 Posted: Dec 15th, 2013 01:11 AM
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Joined: Jan 15th, 2008
Location: New Zealand
Posts: 77
Hi Mr Zeta,
In regards the specification of suitable coils, I think there is an important distinction to be made between winding resistance and working impedance. It seems likely that the use of 5k coils in the scole work refers to the coil winding resistance (dc), hence my earlier comments regarding possible use of 5k relay coils, etc.
The possible use of audio transformers, and their value is a different thing. Yes, there are audio transformers with 5k primary impedance, but the actual dc resistance of the winding is probably only about 300 ohms. I dont think therefore that an audio transformer would be suitable for the device in question, but I am very happy to be proven wrong.