Detonator

Claim 2

A detonator, comprising an explosive, a semiconductor element near enough to the explosive so that the explosive can be set off by heat from the semiconductor element, circuit means for passing a current through said semiconductor element, said circuit means having initiation means for setting the current passed through the element to a value sufficient to heat the element enough to set off the explosive, said circuit means having test means for regulating the current through said semiconductor elements to a value less than sufficient to heat the element enough to set off the explosive, indicating means in said circuit means encoupled to said semiconductor element for indicating a value indicative of current through said semiconductor element.

Claim 3

A detonator as in claim 1, wherein said semiconductor element includes a transistor having a path of major current flow, said initiating means including potential application means for biasing the transistor into a state of high current conduction along the path of major current flow sufficient to heat thE transistor, said test means including potential application means for biasing the transistor into a condition in which the current flow through the path of major current flow is insufficient to heat the transistor enough to set off the explosive, said indicating means including a meter measuring the effect of current flow through said transistor.

Claim 4

A detonator as in claim 1, wherein said semiconductor element is a diode, wherein said initiating means includes a circuit for applying forward current through the diode sufficient to heat the diode enough to set off the explosive, said test means including a circuit for passing a reverse current through the diode insufficient to heat the diode to a level enough to set off the explosive.

Claim 5

A detonator as in claim 2, wherein said test means including a second transistor having a path of major current flow in series with the path of major current flow of said first transistor, said indicating means being connected across the path of major current flow of said second transistor, said initiating means including biasing means for biasing said second transistor into heavy conduction when said initiating means biases said first transistor into heavy conduction, said test means including second biasing means for biasing said second transistor into heavy conduction when said initiating means biases said first transistor into conduction insufficient to set off the explosive, said circuit means including third biasing means for biasing said second transistor into a state of limited conduction and for biasing said first transistor into heavy conduction.

Claim 6

A detonator comprising a blasting cap including an explosion-initiating transistor having a collector and an emitter and a base, lead wires connected to the collector and emitter and base, said blasting cap having an explosive disposed close to the lead wires connected to the collector and emitter of the transistor, a checking transistor having a collector and an emitter and a base, a voltmeter, a power source, a switch, said transistors having respective paths of major current flow between said emitters and said collectors, said checking transistor being connected so that its path of major current flow is in series with the path of major current flow of the initiating transistor for checking current through the initiating transistor, a voltmeter connector to indicate the current through the initiating transistor, said transistors being connected at their base to said power source through said switch to vary the base current so that when both transistors are made conductive an explosion is set off and when either transistor is made conductive said voltmeter indicates predetermined readings in the absence of affects and other readings in the presence of defects.

Claim 7

A detonator comprising a blasting cap including an explosion-initiating transistor having a collector and an emitter and a base, lead wires connected to the collector and emitter and base, said blasting cap having an explosive disposed close to the lead wires connected to the collector and emitter of the transistor, a checking transistor having a collector and an emitter and a base, a voltmeter, a power source, a switch, said transistors having respective paths of major current flow between said emitters and said collectors, said checking transistor being connected so that its path of major current flow is in series with the path of major current flow of the initiating transistor for checking current through the initiating transistor, a voltmeter connector to indicate the current through the initiating transistor, said transistors being connected at their base to said power source through said switch to vary the base current so that when both transistors are made conductive an explosion is set off and when either transistor is made conductive said voltmeter indicates predetermined readings in the absence of affects and other readings in the presence of defects.

Claim 8

A detonator, comprising an explosive, an explosion-initiating transistor forming a path of major current flow and having an emitter and a collector, lead wires connected to the emitter and collector, a checking transistor having an emitter and collector and forming a path of major current flow in series with the path of major current flow of the initiating transistor, said initiating transistor having a base, an AND gate having an output connected to the base of the initiating transistor, and input terminal for an explosion-initiating signal, said input terminal being connected to an input of said AND gate, a NOT gate, said checking transistor having a base, a check terminal for forming an input for a checking signal, said NOT circuit connecting the base of said checking transistor to said check terminal, said transistors forming a common point along their paths of major current flow, an EXCLUSIVE OR gate connected and responsive to the check terminal and the common point, an alarm circuit connected to the output of said EXCLUSIVE OR gate and an inhibitor circuit having an input coupled to the output of said EXCLUSIVE OR gate and connected to an input of said AND gate, said initiating transistor wheN biased fully on together with said checking transistor being biased fully on producing sufficient heat to set off said explosive, said transistors having characteristics so that when one is biased on and the other is biased off the EXCLUSIVE OR gate compares the voltage at the common point with the check input to set off said alarm circuit.

Claim 9

A detonator, comprising an explosive, an explosion-initiating transistor forming a path of major current flow and having an emitter and a collector, lead wires connected to the emitter and collector, a checking transistor having an emitter and collector and forming a path of major current flow in series with the path of major current flow of the initiating transistor, said initiating transistor having a base, an AND gate having an output connected to the base of the initiating transistor, and input terminal for an explosion-initiating signal, said input terminal being connected to an input of said AND gate, a NOT gate, said checking transistor having a base, a check terminal for forming an input for a checking signal, said NOT circuit connecting the base of said checking transistor to said check terminal, said transistors forming a common point along their paths of major current flow, an EXCLUSIVE OR gate connected and responsive to the check terminal and the common point, an alarm circuit connected to the output of said EXCLUSIVE OR gate and an inhibitor circuit having an input coupled to the output of said EXCLUSIVE OR gate and connected to an input of said AND gate, said initiating transistor wheN biased fully on together with said checking transistor being biased fully on producing sufficient heat to set off said explosive, said transistors having characteristics so that when one is biased on and the other is biased off the EXCLUSIVE OR gate compares the voltage at the common point with the check input to set off said alarm circuit.

Claim 10

A detonator, comprising a semiconductor blasting cap having an explosion-initiating diode and an explosive, said diode having an anode and a cathode and lead wires connected to the anode and the cathode, an explosive in said blasting cap disposed close to said diode, circuit means connected to the initiating diode for furnishing current in the forward direction through said diode, said circuit means including a resistance, a voltmeter, an explosion initiating switch, and switch means for applying an inverse bias voltage, said initiating diode having a characteristic such that when a sufficient forward current is applied to the diode the diode is heated sufficiently to set off an explosion and when an inverse bias voltage is applied to the diode the current is insufficient to heat the diode and set off the explosion, indicator means connected to said circuit to indicate the degree of current flow through said diode.

Claim 11

A detonator, comprising a semiconductor blasting cap having an explosion-initiating diode and an explosive, said diode having an anode and a cathode and lead wires connected to the anode and the cathode, an explosive in said blasting cap disposed close to said diode, circuit means connected to the initiating diode for furnishing current in the forward direction through said diode, said circuit means including a resistance, a voltmeter, an explosion initiating switch, and switch means for applying an inverse bias voltage, said initiating diode having a characteristic such that when a sufficient forward current is applied to the diode the diode is heated sufficiently to set off an explosion and when an inverse bias voltage is applied to the diode the current is insufficient to heat the diode and set off the explosion, indicator means connected to said circuit to indicate the degree of current flow through said diode.