Voltage difference detector

Claim 2

A voltage difference detector having first and second signal voltage inputs connected by_matching resistors to the collectors of two grounded emitter transistors of a current mirror constructed such that in operation the current in the collector circuit of the first transistor is matched by that of the second, characterised in that the collector of the second transistor is strapped to the base of a matching third transistor whose emitter provides a reference voltage input.

Claim 3

A voltage difference detector including a pair of current mirrors constructed such that in operation the collector current of a first transistor of each current mirror is matched by an equal collector current in a second transistor of that current mirror, characterised in that the collectors of the second transistors of the two current mirrcrs are respectively strapped to the two bases of two level sensing transistors providing a reference voltage input for the difference detector at their commoned emitters, and wherein the collector circuits of the first and second transistors of each current mirror are provided with a matching pair of resistors which are cross coupled with those of the other current mirror so as to provide first and second signal voltage inputs for the difference detector, with the first signal voltage input connected via one of the resistors with the collector of the first transistor of one of the current mirrors and via another of the resistors with the collector of the second transistor of the other of the current mirrors, and with the second signal voltage input connected respectively with the other two collectors of the transistors of the current mirrors via the other two of the resistors.

Claim 4

A voltage difference detector including a pair of current mirrors constructed such that in operation the collector current of a first transistor of each current mirror is matched by an equal collector current in a second transistor of that current mirror, characterised in that the collectors of the second transistors of the two current mirrcrs are respectively strapped to the two bases of two level sensing transistors providing a reference voltage input for the difference detector at their commoned emitters, and wherein the collector circuits of the first and second transistors of each current mirror are provided with a matching pair of resistors which are cross coupled with those of the other current mirror so as to provide first and second signal voltage inputs for the difference detector, with the first signal voltage input connected via one of the resistors with the collector of the first transistor of one of the current mirrors and via another of the resistors with the collector of the second transistor of the other of the current mirrors, and with the second signal voltage input connected respectively with the other two collectors of the transistors of the current mirrors via the other two of the resistors.

Claim 5

A voltage difference detector including a matched pair of amplifier circuits, wherein each amplifier circuit consists of matched first and second transistors with commoned emitters and matching resistors in their collector circuits that provide first and second inputs of the amplifier circuit, the first transistor being diode connected and having its collector strapped to the base of the second transistor whose collector provides the output of the amplifier circuit characterised in that in said difference detector the outputs of the amplifier circuits are respectively strapped to the bases of two level sensing transistors providing a reference voltage input for the difference detector at their commoned emitters, and wherein the inputs of the amplifier circuits are cross connected to provide a first difference detector input that is connected with the collector circuit of the first transistor of one circuit amplifier and that of the second transistor of the other circuit amplifier and to provide a second difference detector signal voltage input that is connected with the collector circuit of the second transistor of the one circuit amplifier and that of the first transistor of the other circuit amplifier.

Claim 6

A voltage difference detector including a matched pair of amplifier circuits, wherein each amplifier circuit consists of matched first and second transistors with commoned emitters and matching resistors in their collector circuits that provide first and second inputs of the amplifier circuit, the first transistor being diode connected and having its collector strapped to the base of the second transistor whose collector provides the output of the amplifier circuit characterised in that in said difference detector the outputs of the amplifier circuits are respectively strapped to the bases of two level sensing transistors providing a reference voltage input for the difference detector at their commoned emitters, and wherein the inputs of the amplifier circuits are cross connected to provide a first difference detector input that is connected with the collector circuit of the first transistor of one circuit amplifier and that of the second transistor of the other circuit amplifier and to provide a second difference detector signal voltage input that is connected with the collector circuit of the second transistor of the one circuit amplifier and that of the first transistor of the other circuit amplifier.

Claim 7

A differential line receiver incorporating a voltage difference detector as claimed in claim 1, 2 or 3.

Claim 8

A balanced window detector incorporating a voltage difference detector as claimed in claim 1, 2 or 3.