06-06-2013, 09:59 PM
I'll knock up another coil tomorrow with 3 times the number of turns if I can find some nails that are suitable. (nails are for the former). The Rx side doesn't make much sense either, according to the online calculators I have found that the best performance is with 2x the calculated capacitance?
The shape of the Tx coil is probably causing the reduced inductance and on the Rx side I guess that the coupling is causing the reduced value of calculated inductance.
From the calculator;-
Rx coil 1, 14T, 1.75 dia, depth 0.2, Ht 0.2 = 13.3 uH Best cap value 0.66uFd
Rx Coil 2, 20T, 1.75dia, depth 0.25, Ht 0.25 =24.5 uH Best cap value 0.37uFd
The best cap Value refers to the Rx coil cap which showed the best performance within
22nFd (not resonance but fairly close with values I have available)
In both cases calculated resonance should be at about 53KHz ?? Why not 82KHz ??
I'm afraid I've long forgotten the effects of close coupling etc so if anyone can explain what is going on i'll be very happy.
Mike
The shape of the Tx coil is probably causing the reduced inductance and on the Rx side I guess that the coupling is causing the reduced value of calculated inductance.
From the calculator;-
Rx coil 1, 14T, 1.75 dia, depth 0.2, Ht 0.2 = 13.3 uH Best cap value 0.66uFd
Rx Coil 2, 20T, 1.75dia, depth 0.25, Ht 0.25 =24.5 uH Best cap value 0.37uFd
The best cap Value refers to the Rx coil cap which showed the best performance within
22nFd (not resonance but fairly close with values I have available)
In both cases calculated resonance should be at about 53KHz ?? Why not 82KHz ??
I'm afraid I've long forgotten the effects of close coupling etc so if anyone can explain what is going on i'll be very happy.
Mike
