Testing device for pulse convertors in telephone systems - uses test pulse transmitter which simultaneously generates number of pulse trains

摘要

Test pulses are applied to the tested unit, and the beats of pulse trains generated by the sender are the same; the first pulse train, or a single pulse switches on and off the convertor pulse switching means; second and third pulse train control a comparator which links the pulses delivered by the convertor switching means with the second and third pulse train by means of gates; they form from the second and third pulse train comparison blanking pulses during which the switching means must or must not deliver converted pulses; when converted pulses appear outside tolerance limits fixed by the reference blanking pulse trains, and when converted pulses and/or pauses are absent within these tolerance limits, malfunction is signalled or recorded.