초록 ▼

An improved fireset for detonating an explosive includes a voltage monitor arranged to measure a voltage across a quickly dischargeable energy storage device (QDESD), such as a capacitor, and to perform a detonation sequence based at least in part on the voltage measured by the voltage monitor. The

An improved fireset for detonating an explosive includes a voltage monitor arranged to measure a voltage across a quickly dischargeable energy storage device (QDESD), such as a capacitor, and to perform a detonation sequence based at least in part on the voltage measured by the voltage monitor. The fireset employs feedback from the voltage monitor to promote accurate charging of the QDESD and accurate maintenance of charge during an armed state. The voltage monitor also promotes safety by allowing the fireset to indicate when the QDESD is discharged to a safe level, i.e., one which is assured not to result in detonation.

대표청구항 ▼

1. A fireset for detonating an explosive, comprising: a discharge circuit including a quickly dischargeable energy storage device coupled in series with a LEEFI (Low Energy Exploding Foil Initiator);a high voltage source coupled to the discharge circuit to charge the quickly dischargeable energy sto

1. A fireset for detonating an explosive, comprising: a discharge circuit including a quickly dischargeable energy storage device coupled in series with a LEEFI (Low Energy Exploding Foil Initiator);a high voltage source coupled to the discharge circuit to charge the quickly dischargeable energy storage device;a high voltage switch coupled to the discharge circuit and having a control input;a high voltage monitor coupled to the discharge circuit and having an output arranged to provide a voltage proportional to the voltage across the discharge circuit; anda control circuit having an input coupled to the output of the high voltage monitor and an output coupled to the control input of the high voltage switch, the control circuit constructed and arranged to close the high voltage switch based at least in part on the voltage proportional to the voltage across the discharge circuit exceeding a predetermined threshold,wherein the discharge circuit further includes an inductor coupled in series with the quickly dischargeable energy storage device to limit ringing when the high voltage switch is activated. 2. The fireset of claim 1, wherein the control circuit is constructed and arranged to measure the voltage at the output of the high voltage monitor. 3. The fireset of claim 2, wherein the high voltage monitor and the control circuit are each electrically coupled to a common ground reference. 4. The fireset of claim 2, wherein the quickly dischargeable energy storage device includes a high voltage capacitor with a ceramic dielectric. 5. The fireset of claim 4, wherein the high voltage switch includes a MOSFET-controlled thyristor (MCT), and wherein the control input of the high voltage switch is a gate of the MCT. 6. The fireset of claim 5, further comprising a resistor having a first terminal and a second terminal, the second terminal coupled to the gate of the MCT. 7. The fireset of claim 6, further comprising a second capacitor coupled between the first terminal of the resistor and the common ground reference. 8. The fireset of claim 7, further comprising a biasing circuit coupled to the first terminal of the resistor to negatively bias the gate of the MCT. 9. The fireset of claim 4, wherein the high voltage capacitor is provided in a package that includes a bleeder resistor coupled in parallel with the high voltage capacitor. 10. The fireset of claim 1, wherein the high voltage monitor includes a resistive voltage divider. 11. The fireset of claim 1, wherein the discharge circuit further includes a current sensing resistor coupled in series with the quickly dischargeable energy storage device. 12. The fireset of claim 1, wherein the control circuit has a second output coupled to the high voltage source to control the high voltage source to charge the quickly dischargeable energy storage device. 13. A fireset for detonating an explosive, comprising: a discharge circuit including a high voltage capacitor coupled in series with a LEEFI (Low Energy Exploding Foil Initiator);a high voltage source coupled to the discharge circuit to charge the high voltage capacitor;a high voltage switch coupled to the discharge circuit and having a control input;a high voltage monitor coupled to the discharge circuit and having an output arranged to provide a signal proportional to the voltage across the discharge circuit; anda control circuit having an input electrically coupled to the output of the high voltage monitor, a first output electrically coupled to the control input of the high voltage switch, and a second output electrically coupled to the high voltage source, the control circuit constructed and arranged to close the high voltage switch based at least in part on the signal proportional to the voltage across the discharge circuit exceeding a predetermined threshold,wherein the high voltage switch is coupled to a first ground and the control circuit is coupled to a second ground, and wherein the fireset further comprises an inductive element through which the first ground is coupled to the second ground. 14. The fireset of claim 13, wherein the high voltage capacitor has a ceramic dielectric, and wherein the high voltage switch includes a mosfet-controlled thyristor. 15. A method of detonating an explosive using a fireset, comprising: charging, from a high voltage source, a discharge circuit including a quickly dischargeable energy storage device coupled in series with a LEEFI (Low Energy Exploding Foil Initiator);monitoring a voltage across the discharge circuit; andactivating, by a control circuit, a first control signal to close a high voltage switch coupled to the discharge circuit, based at least in part on the monitoring indicating that the voltage across the discharge circuit exceeds a predetermined threshold,wherein the method further comprises: prior to charging the discharge circuit, activating, by the control circuit, a second control signal to charge the discharge circuit;receiving, by the control circuit, an indication that detonation is to be aborted;deactivating, by the control circuit, the second control signal;bleeding off charge from the quickly dischargeable energy storage device to reduce the voltage across the discharge circuit to a safe level below which discharge of the quickly dischargeable energy storage device through the LEEFI does not result in detonation; andindicating a safe condition in response to the monitoring of the voltage across the discharge circuit indicating that the voltage across the discharge circuit is below the safe level. 16. The fireset of claim 13, wherein the discharge circuit further includes an inductor coupled in series with the high voltage capacitor to limit ringing when the high voltage switch is activated. 17. The fireset of claim 13, wherein the high voltage switch comprises a MOSFET-controlled thyristor (MCT) that conducts current from the high voltage capacitor through the LEEFI when the high voltage switch is closed. 18. The fireset of claim 17, wherein the MCT has a gate and wherein the fireset further comprises a biasing circuit coupled to the gate of the MCT to bias the MCT to an off condition. 19. The fireset of claim 13, further comprising a safe indicator to indicate that the fireset is in a safe, non-explodable state. 20. The fireset of claim 13, wherein the discharge circuit further includes a current sense resistor coupled to the control circuit to enable the control circuit to measure current through the LEEFI.