
(from the article `motion-picture technology`) ...some kind of signal in synchronism with the intermittent when an auxiliary, magnetic-tape sound recorder is used, so that the sound record can ...
Found on
http://www.britannica.com/eb/a-z/s/199

(sync pulse generator, SPG). Device that generates synchronizing pulses needed by video source equipment to provide proper signal timing. Pulses typically produced by a sync generator could be sub-carrier, sync, blanking, H and V drives and colour black. Most commonly usedin CCTV are H and V drives.
Found on
http://www.zoo.co.uk/~z0001325/Glossary.html

an electronic generator that supplies synchronizing pulses to television scanning and transmitting equipment.
Found on
https://www.infoplease.com/dictionary/sync-generator
No exact match found.