Traveling-wave-tube protection circuit

Claim 2

A protection circuit for an electronic device having a current path within said device comprising: a transformer having a primary and a secondary winding, means connecting said primary winding serially with said current path; a d.c. restorer circuit having an input coupled to said secondary winding; a comparator circuit coupled to the output of said d.c. restorer circuit and having a reference voltage generator which produces a predetermined voltage representative of current desired in said path, and providing an output signal when the voltage at the output of said restorer circuit exceeds said reference voltage; an integrator having an input connected to the output of said comparator and providing an output signal when said comparator output signal remains present for longer than a predetermined period of time; and protection means coupled to said integrator and responsive to an output signal therefrom for shutting off power to said device.

Claim 3

A protection circuit for an electronic device having a plurality of current paths within said device, comprising: a plurality of detection paths, each path including a transformer having a primary and a secondary winding, said primary being connected serially with one of said current paths; a d.c. restorer circuit having an input coupled to said secondary winding; a comparator circuit coupled to the output of said d.c. restorer circuit and having a reference voltage generator which produces a predetermined voltage representative of current desired in said path, and providing an output signal when the voltage at the output of said restorer circuit exceeds said reference voltage; an integrator having an input connected to the output of said comparator and providing an output signal when said comparator output signal remains present for longer than a predetermined period of time, the output of said integrator forming the output of said detection path; a decision circuit having a plurality of input terminals, and connections between different outputs of said detection paths to different input terminals of said decision circuit, said decision producing an output signal upon the occurence of a signal present at least one of said input terminals of said decision circuit; and protection means of shutting off power to said device upon occurence of said decision circuit output signal.

Claim 4

A protection circuit for an electronic device having a plurality of current paths within said device, comprising: a plurality of detection paths, each path including a transformer having a primary and a secondary winding, said primary being connected serially with one of said current paths; a d.c. restorer circuit having an input coupled to said secondary winding; a comparator circuit coupled to the output of said d.c. restorer circuit and having a reference voltage generator which produces a predetermined voltage representative of current desired in said path, and providing an output signal when the voltage at the output of said restorer circuit exceeds said reference voltage; an integrator having an input connected to the output of said comparator and providing an output signal when said comparator output signal remains present for longer than a predetermined period of time, the output of said integrator forming the output of said detection path; a decision circuit having a plurality of input terminals, and connections between different outputs of said detection paths to different input terminals of said decision circuit, said decision producing an output signal upon the occurence of a signal present at least one of said input terminals of said decision circuit; and protection means of shutting off power to said device upon occurence of said decision circuit output signal.

Claim 5

A protection circuit in accordance with claim 2 wherein there is provided a power supply current in each current path between said primary winding and an element of said electronic device.

Claim 6

A protection circuit in accordance with claim 3 wherein said electronic device is a traveling-wave tube and said current paths include a body current path and a collector current path.

Claim 7

A protection circuit in accordance with claim 2 wherein said electronic device is a traveling-wave tube.

Claim 8

A protection circuit in accordance with claim 4 wherein said protection means includes means to terminate power to the grid, body, and collector of said traveling wave tube.

Claim 9

A protection circuit according to claim 1 wherein said d.c. restorer comprises: a first differential amplifier having an inverting input, a non-inverting input, and an output; a second differential amplifier having an inverting input, a non-inverting input, and an output; reference voltage means; capacitive means connected between said inverting input of said first amplifier and said reference voltage means; a first signal path interconnecting said inverting terminal of said first amplifier with said inverting terminal of said second amplifier, said first signal path including a resistance; a second signal path interconnecting said non-inverting input of said first amplifier with said non-inverting input of said amplifier, said second signal path including an attenuation network; a first feedback path interconnecting said output of said first amplifier with said inverting input of said first amplifier, said feedback path including a normally open voltage-controlled switch which opens whenever the current therethrough becomes less than a predetermined amount and closes whenever a predetermined voltage is applied thereto; and a resistive feedback path interconnecting said output of said second amplifier with said inverting input of said second amplifier, whereby a periodic electrical signal, when applied to said non-inverting input of said first amplifier, will have added to it a constant d.c. level and the resultant signal shall be present at said output of said second amplifier.

Claim 10

The d.c. restorer of claim 7 wherein said capacitative means comprises a capacitance and resistance in parallel.

Claim 11

The d.c. restorer of claim 7 wherein said reference voltage means is ground.