Firing-readiness capacitance check of a pyrotechnic device such as an electronic detonator

• US 20050188871A1
• Filed: 04/12/2005
• Published: 09/01/2005
• Est. Priority Date: 07/15/2003
• Status: Abandoned Application

• Current Assignee: Special Devices Incorporated (Daicel Corporation)
• Original Assignee: Special Devices Incorporated (Daicel Corporation)
• Inventors: Teowee, Gimtong, Jennings, David T. III, Forman, David M.
• Application Number:
  US11/103,909
• Publication Number:
  US 20050188871A1
• Time in Patent Office: Days
• US Class Current: 102/200
• CPC Class Codes: F42D 1/055 specially adapted for firing multiple charges with a time delay

Abstract

Firing-readiness diagnostics in an electronic pyrotechnic device such as an electronic detonator or an electronic blasting system thereof. The diagnostics may include a check for any incompatible attached devices, a resistance or continuity check of an ignition element, and/or a capacitance check of a firing capacitor.

Claims

1. An electronic detonator for use in mining or blasting and having firing-readiness diagnostics, comprising an igniter that includes a firing capacitor, and electronic circuitry configured and/or programmed to check the capacitance of the firing capacitor against one or more capacitance limits.

2. The electronic detonator of claim 1, wherein said one or more capacitance limits includes a lower capacitance limit.

3. The electronic detonator of claim 1, wherein said one or more capacitance limits includes an upper capacitance limit.

4. The electronic detonator of claim 1, wherein said electronic circuitry is configured and/or programmed to check that the firing capacitor has a capacitance that is above a lower capacitance limit and below an upper capacitance limit.

5. The electronic detonator of claim 2, wherein said electronic detonator is configured and/or programmed to charge said firing capacitor using a controlled charging process, and said electronic circuitry is configured and/or programmed to check that the duration of controlled charging of said firing capacitor exceeds a minimum time limit that corresponds to said lower capacitance limit.

6. The electronic detonator of claim 3, wherein said electronic detonator is configured and/or programmed to charge said firing capacitor using a controlled charging process, and said electronic circuitry is configured and/or programmed to check that the duration of controlled charging of said firing capacitor does not exceed a maximum time limit that corresponds to said upper capacitance limit.

7. The electronic detonator of claim 4, wherein said electronic detonator is configured and/or programmed to charge said firing capacitor using a controlled charging process, and said electronic circuitry is configured and/or programmed to check that the duration of controlled charging of said firing capacitor exceeds a minimum time limit that corresponds to said lower capacitance limit but does not exceed a maximum time limit that corresponds to said upper capacitance limit.

8. The electronic detonator of claim 5, wherein said controlled charging process is a constant-current, rail-voltage limited process.

9. The electronic detonator of claim 6, wherein said controlled charging process is a constant-current, rail-voltage limited process.

10. The electronic detonator of claim 7, wherein said controlled charging process is a constant-current, rail-voltage limited process.

11. The electronic detonator of claim 10, wherein said electronic detonator includes an application-specific integrated circuit that contains said electronic circuitry, and wherein said igniter is hermetically sealed and said ignition element is a bridgewire.

12. An electronically connected system for use in mining or blasting comprising:

a) a master device;

b) a bus connected to said master device; and

,

c) a plurality of electronic detonators connected to said bus, each said electronic detonator comprising an igniter that includes a firing capacitor, and electronic circuitry configured and/or programmed to check the capacitance of the firing capacitor against one or more capacitance limits.

13. The electronically connected system of claim 12, wherein said electronic circuitry is configured and/or programmed to check that the firing capacitor has a capacitance that is above a lower capacitance limit and below an upper capacitance limit.

14. The electronically connected system of claim 13, wherein said electronic detonator is configured and/or programmed to charge said firing capacitor using a controlled charging process, and said electronic circuitry is configured and/or programmed to check that the duration of controlled charging of said firing capacitor exceeds a minimum time limit that corresponds to said lower capacitance limit but does not exceed a maximum time limit that corresponds to said upper capacitance limit.

15. The electronically connected system of claim 14, wherein said controlled charging process is a constant-current, rail-voltage limited process.

16. A method of operating a system of electronic detonators for use in mining or blasting, comprising the following steps:

a) providing a master device and a bus connected to the master device;

b) connecting a plurality of electronic detonators each having a firing capacitor to said bus;

c) issuing one or more commands from said master device on said bus; and

,

d) after step c), checking the capacitance of the firing capacitor against one or more capacitance limits.

17. The method of claim 16, further comprising the step of issuing information to said master device from any electronic detonator that fails said capacitance check.

18. The method of claim 16, wherein step d) includes checking that the firing capacitor has a capacitance that is above a lower capacitance limit and below an upper capacitance limit.

19. The method of claim 18, further including the step of charging said firing capacitor using a controlled charging process, wherein step d) includes checking that the duration of controlled charging of said firing capacitor exceeds a minimum time limit that corresponds to said lower capacitance limit but does not exceed a maximum time limit that corresponds to said upper capacitance limit.

20. The method of claim 19, wherein said controlled charging process is a constant current, rail-voltage limited process, and step d) is performed during said step of charging.