Pulse generator

Claim 2

A pulse generator comprising a voltage supply, a trigger stage for periodically interrupted operation of a plurality of loads connected in parallel, a capacitor and a precision resistor connected in series between said plurality of loads and said voltage supply during the operating pauses of said plurality of loads, a switching unit responsive to short voltage peaks and retaining the state caused by said voltage peaks at least until said switching unit receives a voltage which is different than a threshold voltage value, means for connecting said switching unit to said precision resistor for applying said voltage peaks which appear at said precision resistor on interruption of the operation of said loads to said switching unit, means for applying said threshold voltage to said switching unit, and means responsive to a state of said switching unit caused by a voltage peak indicative of a load failure for varying the rate of interruption of the operation of said loads thus providing an indication of load failure.

Claim 3

A pulse generator comprising a voltage supply, a trigger stage for periodically interrupted operation of a plurality of loads connected in parallel, a first capacitor for controlling the frequency of the interrupted operation of said loads, a second capacitor and a precision resistor connected in series between said plurality of loads and said voltage supply during the operating pauses of said plurality of loads, a switching unit including an input electrode and a control electrode, said switching unit being responsive to short voltage peaks applied to said control electrode and retaining the state caused by said voltage peaks at least until said input electrode receives a voltage which is different than a threshold voltage value, means for connecting said control electrode of said switching unit to said precision resistor for applying said voltage peaks which appear at said precision resistor on interruption of the operation of said loads to said control electrode, means for applying said threshold voltage to said input electrode, a Voltage divider, and means responsive to a state of said switching unit caused by a voltage peak indicative of a load failure for connecting said voltage divider to said first capacitor for reducing the charging voltage of said first capacitor depending on the ratio of said voltage divider to increase said frequency of said interruptions.

Claim 4

A pulse generator comprising a voltage supply, a trigger stage for periodically interrupted operation of a plurality of loads connected in parallel, a first capacitor for controlling the frequency of the interrupted operation of said loads, a second capacitor and a precision resistor connected in series between said plurality of loads and said voltage supply during the operating pauses of said plurality of loads, a switching unit including an input electrode and a control electrode, said switching unit being responsive to short voltage peaks applied to said control electrode and retaining the state caused by said voltage peaks at least until said input electrode receives a voltage which is different than a threshold voltage value, means for connecting said control electrode of said switching unit to said precision resistor for applying said voltage peaks which appear at said precision resistor on interruption of the operation of said loads to said control electrode, means for applying said threshold voltage to said input electrode, a Voltage divider, and means responsive to a state of said switching unit caused by a voltage peak indicative of a load failure for connecting said voltage divider to said first capacitor for reducing the charging voltage of said first capacitor depending on the ratio of said voltage divider to increase said frequency of said interruptions.

Claim 5

A pulse generator defined in claim 2, wherein said precision resistor has a value substantially equal to the total resistance of two loads in parallel divided by the sqaure root of two.

Claim 6

A pulse generator defined in claim 2, wherein said switching unit comprises a thyristor, the control electrode of which is connected by said connecting means to said precision resistor.

Claim 7

A pulse generator as defined in claim 4, wherein said thyristor further includes two main electrodes , and wherein said generator further comprises a second voltage divider connected to said voltage supply, a tap on said second voltage divider connected to one of said two main electrodes of said thyristor, a first transistor acting to turn on said thyristor and having a collector-emitter path through which said second voltage divider is connected to said voltage, supply, said second voltage divider supplying a bias voltage to said thyristor which ensures, when said first transistor is conducting, that said thyristor fires on receipt of a voltage peak through said connecting means on interruption of the operation of said loads when said loads are intact, and that said thyristor remains uneffected by the receipt of a voltage peak on interruption of the operation of said loads when a failure exits in said loads.

Claim 8

A pulse generator as defined in claim 5, further comprising a second transistor whose collector is connected to the base electrode of said first transistor and a third transistor in said trigger stage, whose collector is connected to the base electrode of said second transistor.

Claim 9

A pulse generator as defined in claim 6, further comprising a second resistance connected between the other main electrode of said thyristor and the ground side of voltage supply, a fourth transistor which is conducting when said thyristor is conducting and to the base of which the voltage drop across said second resistance is applied, a fifth transistor which is cut off when said fourth transistor is conducting and to the base of which one resistance of said first voltage divider is connected so as to be connected to the ground side of said voltage supply through said fifth transistor when conducting.

Claim 10

A pulse generator as defined in claim 7, wherein said first transistor is a p-n-p transistor and said second, third, fourth and fifth transistors are n-p-n transistors.

Claim 11

A pulse generator as defined in claim 7, wherein the circuit of said pulse generator is an integrated solid state circuit.

Claim 12

A pulse generator as defined in claim 7, wherein the circuit of said pulse generator is a thick film circuit.

Claim 13

A pulse generator as defined in claim 7, wherein the circuit of said pulse generator is a thin film circuit.

Claim 14

A pulse generator as defined in claim 6, further comprising a relay winding connected to the collector path of said third transistor for energization when said first of said plurality of transistors is inducting, and a pair of make contacts operated by said relay winding an bridging said first capacitor and its associated resistance for connecting said loads directly to said voltage supply when the contacts are made.

Claim 15

A pulse generator as defined in claim 12, further comprising a third resistance of high value bridging said make contacts.