.~.~ Preselected or synchronous frequency responsive
DEFINITION
Classification: 335/101
(under subclass 99) Subject matter wherein the device is adapted to selectively operate at a predetermined frequency of the alternating operating current or wherein resonant vibration of a tuned reed armature will only occur when the cyclic period of the alternating current is the same as the resonant frequency of the tuned reed.
(1) Note. A large number of the patents found here are analogous to those to be found in subclass 94 above, the difference residing in the fact that in this subclass the vibrating member is comprised of the armature itself while in the vibrator group above the armature is generally separate from the vibratory contact actuating means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
70, for frequency responsive or synchronous motor switch actuating means.
78, for polarized relays which may utilize in alternating current source for the magnetic coil.
93+, for switches of the vibratory type which may or may not be restricted to alternating current operation. 243+, for alternating current responsive electromagnets with vibrating armature structure.
SEE OR SEARCH CLASS
178, Telegraphy,
47+, for harmonic or vibrating reed type telegraph transmitter or receiver means.
307, Electrical Transmission or Interconnection Systems, particularly
87, for frequency responsive connecting and disconnecting plural supply systems and subclass 129 for frequency responsive switching systems in general.
310, Electrical Generator or Motor Structure,
25, for tuned reed type motors or generators and subclasses 162+, for synchronous motor or generator structures.
318, Electricity: Motive Power Systems,
700+, for synchronous motor control systems.
361, Electricity: Electrical Systems and Devices,
160+, for frequency responsive relay systems, particularly subclasses 171+ for code responsive electric circuits for relays, and subclass 183 for plural relays that are frequency responsive.
