Transient generator

A transient generator comprising a series discharge circuit including a discharge capacitor, output terminals, and the anode and cathode of a silicon controlled rectifier;

• a high voltage DC charging circuit connected across said capacitor and having a switching transistor therein, circuit means for determinng the production of a transient and having an output signal to initiate said transient, and coupler means responsive to said signal to make said transistor nonconductive and to trigger said silicon controlled rectifier for capacitor discharge through said discharge circuit upon the occurrence of said signal.

In electrical apparatus, means for producing a signal at any one of a number of equally spaced phase angles in a cycle in reference to an input alternating current, which comprises means for converting said alternating current into a logic level change upon each crossing of the zero voltage axis, a comparator and a voltage controlled oscillator controlled by the output of said comparator defining a phase locked loop, circuit means for delivering the output of said converting means to the reference input terminal of said comparator, said oscillator having a multi pulse output per logic level cycle, pulse counting means for counting the output cycles of said oscillator, circuit means connected to said counting means to return a synchronizing pulse to the feedback input terminal of said comparator at the conclusion of a count to said number of phase angles to synchronize said synchronizing pulse with said logic level cycle and to reset said counting means, and means for deriving and producing a signal from said counting means at any predetermined count within said cycle.

In electrical apparatus, means for producing a signal at any selected phase angle from 0.degree. to a multiple of 360.degree. in reference to an input alternating current which comprises means for converting said alternating current into a logic level change upon each crossing of the zero voltage axis, a comparator and a voltage controlled oscillator controlled by the output of said comparator defining a phase locked loop, circuit means for delivering the output of said converting means to the reference input terminal of said comparator, said oscillator having a multipulse output per logic level cycle, sufficient serially arranged decade counters to count to said multiple receiving the output pulses of said oscillator connected to deliver synchronizing pulses to the feedback input terminal of said comparator at 360 pulses and multiples thereof to synchronize said synchronizing pulses with said logic level cycle and to reset said counters, means for deriving and producing an output signal from said counters at any predetermined count up to said multiple, and gating means connected to receive said signal and to inhibit the application of said synchronizing pulses only to the counter resets until an output signal has been first produced.

A transient generator for producing a series of transients at any desired repetition rate within a range, comprising a series discharge circuit which includes a capacitor, a pair of output terminals, and the anode and cathode of a silicon controlled rectifier;

• DC circuit means for charging said capacitor, means for supplying triggering pulses to said silicon controlled rectifier at said rate, and means for interrupting said charging circuit during capacitor discharge and thereafter restoring said circuit, said pulse supplying means including a phase locked loop having a reference input terminal, a feedback input terminal, and a pulse output, a reference frequency source for supplying a reference frequency to the reference input terminal of said phase locked loop, pulse counting means connected to the output of said phase locked loop adjustable to any count within the range of said counting means, circuit means for delivering a synchronizing pulse from said counting means to the feedback input terminal of said phase locked loop and for resetting said counting means upon the arrival at said count, and circuit means connected to the output of said phase locked loop for delivering the pulses thereof to the gate of said silicon controlled rectifier.