|P.O. ENGINEERING DEPT.
Issue 1, 8.10.38
ELECTRICAL CLOCKS - IMPULSE TYPE
Clock No. 32
Clock No. 32 is provided for synchronizing 1-second dial clocks in conjunction with
Clocks Nos. 30 and 36 (see B 1304). The clock is illustrated in Figs. 1 and 2 and is connected in circuit in the manner indicated in diagrams GMT 26, 34, 35, and 36.
One-second impulses from the pulse distribution circuit energize the electromagnet M attracting the armature A
to the left. To an extension of the armature is attached a spring controlled pawl P, which rotates a propelling wheel R, one tooth for each impulse received. To the arbor of this propelling wheel are attached two disks Dl and P2; the foremost disk Dl rotates once a minute, and disk P2 once an hour. In the periphery of each disk is a V-shaped notch situated at the index 60. Adjacent to these disks is a contact C1, which is normally closed in all positions of the disks except when the two notches are in alignment. The contact C1 is then broken and the circuit through the electromagnet is interrupted. The circuit remains broken until the
Clock No. 30 reaches the hour, whereupon the circuit is completed by the release of the relay which provides an alternative circuit for driving
the Clock No. 32. Contact C1 is remade upon receipt of the next impulse.