Walter Jones Tone generator (photo 685D)
A later model of Telephone exchange tone generator. Reading the plates, it seems to incorporate a Dynomotor that runs off 50v DC and generates 75V AC @ 20 Hz (ringing Tone) and the dynomotor also drives a tone generator that produces 400 CPS (Hz) 'engaged tone' and 175 CPS (Hz) for 'dialing tone'. The switches at the end are operated by cams to produce the necessary interuptions to the tones.
Walter Jones Tone generator (photo 685D)
A later model of Telephone exchange tone generator. Reading the plates, it seems to incorporate a Dynomotor that runs off 50v DC and generates 75V AC @ 20 Hz (ringing Tone) and the dynomotor also drives a tone generator that produces 400 CPS (Hz) 'engaged tone' and 175 CPS (Hz) for 'dialing tone'. The switches at the end are operated by cams to produce the necessary interuptions to the tones.