An electronic tone ringer for telephones

A SIGNALING DEVICE, comprising essentially an input rectifier, an oscillator, and a sound transducer (the handset receiver), has been developed for use in telephone instruments which are too small to accommodate the electromagnetic type of ringer. It responds to present standard ringing voltages and frequencies, and does not respond to dial pulses. Electronic signals of this type are also suitable for use in electronic switching systems, which cannot handle the power required by electromagnetic ringers.