Selectively actuable electrical circuit

A control circuit for selectively actuating an electrically ignitable load comprising:

• first and second input lead wires for coupling to a power source for igniting said load;
• first and second output terminals for coupling to said load to be actuated;
• at least one first inductor electrically coupled between said output terminals;
• and
• at least one second inductor coupling at least one of said input lead wires with at least one of said output terminals, said first and second inductors being electromagnetically coupled to one another such that magnetic flux produced by current flowing in said first inductor opposes the magnetic flux produced by current flowing in said second inductor.

A control circuit for actuating an electrically ignitable load comprising:

• first and second input lead wires for coupling to a power source for igniting said loads;
• first and second output terminals for coupling to said load to be actuated;
• first and second inductors coupled in series with one another and coupling said first and second input lead wires to one another;
• a third inductor coupling said first input lead wire with said first output terminal, and being electromagnetically coupled to said first inductor such that the magnetic flux produced by current flowing in the first inductor opposes the magnetic flux produced by current flowing in the third inductor;
• and
• a fourth inductor coupling said second input lead wire with said second output terminal, and being electromagnetically coupled to said second inductor.

A control circuit for actuating an electrically ignitable load comprising:

• first and second input lead wires for coupling to a power source for igniting said load;
• first and second output terminals for coupling to said load to be ignited;
• first, second, third and fourth inductors in series with one another and coupling said first and second terminals to one another;
• a fifth inductor coupling said first input lead wire with said first output terminal;
• a sixth inductor coupling said second input lead wire with said second output terminal;
• said first, third, and fifth inductors being electromagnetically coupled to one another and said second, fourth, and sixth inductors being electromagnetically coupled to one another such that the magnetic flux produced by current flowing in the third inductor opposes the magnetic flux produced by current flowing in the fifth inductor and the magnetically flux produced by current flowing in the second inductor opposes the magnetic flux produced by current flowing in the sixth inductor.

A detonator comprising:

• a fusehead resistive load;
• a ferrite bead having first and second passages therein each passage extending from a first end of said ferrite bead to a second end of said bead;
• a pair of lead wires coupled to said resistive load and passing one each through said first and second passages of said ferrite bead from said second to said first end thereof and extending beyond said second end for coupling to a power source;
• an inductor wire threaded through said first and second passages such that its two ends extend through said passages at said first end of said ferrite bead, one end of said inductor wire coupled to each of said lead wires so that a portion of said inductor wire shares a passage in common with each of said lead wires, the ends of said inductor wire being cross coupled to said lead wires at said first end of said ferrite bead.

A detonator comprising:

• a fusehead resistive load;
• a ferrite bead having first and second passages therein each passage extending from a first end of said ferrite bead to a second end of said bead;
• a pair of lead wires coupled to said resistive load and passing one each through said first and second passages of said ferrite bead from said first to said second end thereof and extending through said first end for coupling to a power source;
• an inductor wire threaded twice through each of said first and second passages such that its two ends extend through said passages at said second end of said ferrite bead, one end of said inductor wire coupled to each of said lead wires so that a portion of said inductor wire shares a passage in common with each of said lead wires, the ends of said inductor wire coupled to said lead wires at said second end of said ferrite bead.