12-09-2021, 12:35 PM
Certainly for frame scan, resistance of the scan coils tends to dominate over inductive reactance, and that is independent of the number of turns (double the turns and the inductance quadruples, but so does the resistance).
For line scan coils, the same applies though luckily here, the numbers are such that inductive reactance dominates. But as Jeffrey says, more turns starts to add extra stray capacitance, which hurts. So, fewer turns are often chosen.
Whether valve or transistor is immaterial as if you drive the coils via a matching transformer, that can match to anything. Certainly circuit impedances are such that it might be possible to drive the coils directly without a transformer from a solid-state circuit. Though, DC blocking still needs to be considered, after all, you don't want the spot to be only scannable from centre to right, and from centre down, only...
For line scan coils, the same applies though luckily here, the numbers are such that inductive reactance dominates. But as Jeffrey says, more turns starts to add extra stray capacitance, which hurts. So, fewer turns are often chosen.
Whether valve or transistor is immaterial as if you drive the coils via a matching transformer, that can match to anything. Certainly circuit impedances are such that it might be possible to drive the coils directly without a transformer from a solid-state circuit. Though, DC blocking still needs to be considered, after all, you don't want the spot to be only scannable from centre to right, and from centre down, only...
