Electric device
AssigneeImperial Chemical Industries PLC
InventorAndrew Stratton
Life of this patent
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Abstract
An electrically ignited load such as a fusehead is connected to the secondary winding of a transformer. The secondary winding is magnetically linked to a primary winding through a magnetic circuit and the transformer is constructed so as to provide a substantial leakage inductance associated with the secondary winding and effectively connected in series with the load to be ignited. The structure selectively passes electrical ignition energy to the load only in response to input electrical energy having predetermined magnitude and frequency characteristics.
Claims44
An electrical control circuit for selectively energizing an electrically ignited load only in response to input electrical energy from an a.c. source having predetermined electrical parameters, said control circuit comprising:
- first and second inductors having mutual linkage therebetween,
- said first inductor being adapted for connection to said a.c. source,
- said second inductor being adapted for connection to said load,
- at least one of said first and second inductors being constructed and constructed and connected in circuit to provide a substantial protective inductance effectively connected in series with said load, and
- an energy dissipation means, effectively coupled to said at least one inductor, for dissipating input electrical energy as a function of the voltage across and/or current though at least one of said first and second inductors.
An electrical control circuit for selectively energizing an electrically ignited load only in response to input electrical energy having predetermined electrical characteristics, said control circuit comprising:
- a transformer including a magnetically permeable structure, a primary winding adapted for connection to a source of electrical energy, and a secondary winding adapted for connection to said load, both said windings being magnetically coupled to said magnetically permeable structure,
- said transformer being constructed so as to provide a substantial leakage inductance associated with at least one of said primary and secondary windings.
An electrical control circuit for selectively energizing an electrically ignited load only in response to input electrical energy having a predetermined frequency, said control circuit comprising:
- a first inductor adapted for connection with a source of electrical energy,
- a second inductor adapted for series electrical connection with said load and coupled to said first inductor for receiving energy supplied from said source, and
- an energy dissipation means effectively coupled to at least one of said first and second inductors for dissipating input electrical energy as a function of the voltage across and/or current through at least one of said first and second inductors,
- said first inductor increasingly shunting input electrical energy from said load as frequency is decreased and said second inductor having sufficient relative inductance to increasingly block input electrical energy from reaching said load as frequency is increased such that only input electrical energy of said predetermined frequency is sufficiently coupled to said load to cause its ignition.
A system for selectively operating an electrically ignited load circuit from an a.c. source, said system comprising:
- inductive circuits for coupling the load to said source,
- said inductive circuits having a first winding connected to said source and a second winding, at least part of which may be common with the first, said second winding being connected to the load circuit, and
- first and second magnetic currents,
- at least part of said first and second windings being linked to said first magnetic circuit and at least part of said second winding being linked to said second magnetic circuit,
- said second magnetic circuit not being linked by the first winding and thereby providing a protective series inductance as an effective part of the second winding.
An electric device for selectively activating an electrical load circuit, said device comprising:
- an electric load circuit,
- inductive circuits in the form of a transformer having a first winding adapted for connection to a source of electrical energy and a second winding connected to said load circuit,
- a first magnetic circuit mutually linking at least part of said first and second windings, and
- a second magnetic circuit self-linking at least part of said second winding, which second magnetic circuit is not magnetically linked to the first winding thereby providing a protective series inductance as part of said second winding.
An electric device for selectively activating an electrical load circuit, said device comprising:
- an electric load circuit,
- inductive circuits having a first winding adapted for connection to a source of electrical energy and a second winding which includes at least part of the first winding,
- said second winding being connected to said load circuit,
- a first magnetic circuit linking that part of the first winding that is included in the second winding, and
- a second magnetic circuit linking that part of the second winding that does not include the first winding, which second magnetic circuit is not linked to the first winding thereby providing a protective series inductance as part of said second winding.
Dependencies are inferred from the claim text.