These were all energized by the same source ( at local power frequency or from a motor-generator set ) and so inherently maintained synchronism.
22.
It is important to note that contrary to the popular belief, NTSC or PAL video standards are not directly linked to mains power frequency.
23.
Large power transformers use multiple-stranded conductors as well, since even at low power frequencies non-uniform distribution of current would otherwise exist in high-current windings.
24.
Rotary gaps operated in two modes, power frequency ( typically, 100 or 120 breaks / second, corresponding to 50 Hz or 60 Hz supply ).
25.
And the flicker frequency is 100 or 120 per second, twice the power frequency .-- Anon, August 14, 2007, 22 : 12 ( UTC ).
26.
The use of shielded cables in security systems provides some protection from power frequency and radio frequency interference, reducing the number of false alarms being generated.
27.
It is important to realise that for a ground loop to cause problems, there must be a local magnetic field produced by power frequency or other systems.
28.
Some diodes and thyristors are suited for relatively slow speed and are useful for power frequency switching and control; certain thyristors are useful at a few kilohertz.
29.
_a church in Florida that says broadcasting on a low power frequency will allow sermons to be heard in senior citizen complexes by people unable to attend services;
30.
Parametric amplifiers use an AC supply as their power source, but the AC source must be high frequency, not the standard 50 Hz or 60 Hz power frequency.
