| 摘要 |
1,076,668. Measuring time delays. TELEFONAKTIEBOLAGET L.M. ERICSSON. Oct. 15, 1965, No.43879/65. Heading G1U. An arrangement for measuring the time delay of a circuit MOBJ comprises: a variable frequency pulse source PULS connected to a reference channel E and a channel C containing circuit MOBJ to be measured; a first NAND-circuit 1 having one input connected to the output from each channel; a second NAND-circuit 2 having one input connected to channel E, and the other connected to the output of the first NAND-circuit; integrator circuits INTF, INTD connected to the outputs from the two NAND-circuits D, F; and an indicator for comparing the outputs from the two indicators. The pulse signals on D, F have mark/ space ratios dependent on the delay T of circuit MOBJ and the frequency f of the pulse source PULS. If the frequency of the pulse source is varied until the two mark/space ratios are equal, as indicated by a null on the indicator, then T = “f. In order to reshape the pulse after passing through circuit MOBJ they are fed through a limiter LIMT and an amplifier AMPL, a variable delay JUST being included in the reference are to compensate for the delay in these elements. The pulse frequency is determined by a divider chain FDIV and frequency meter FRVR connected to the pulse source PULS. |
