Electrically initiated inertial igniters for thermal batteries and the like
A method for electrically initiating an inertial igniter for a munition. The method including: providing an electrical energy generating device to generate a voltage over a duration responsive to an acceleration of the munition; providing a first electrical storage device connected to the electrical energy generating device through a voltage divide circuit to receive a portion of the voltage over the duration; providing a second electrical storage device connected to the electrical energy generating device to accumulate the voltage; and providing a circuit powered by a connection to the electrical energy generating device, the circuit determining an all-fire condition based on both a connection to the first electrical storage device that receives the portion of the voltage and the duration of voltage generation and a predetermined accumulated voltage of the second electrical storage device.
1. An electrically initiated inertial igniter for a munition, the electrically initiated inertial igniter comprising:
an electrical energy generating device configured to generate a voltage over a duration responsive to an acceleration of the munition;
a first electrical storage device connected to the electrical energy generating device through a voltage divide circuit to receive a portion of the voltage over the duration;
a second electrical storage device connected to the electrical energy generating device to accumulate the voltage; and
a circuit powered by a connection to the electrical energy generating device, the circuit configured to determine an all-fire condition based on both a connection to the first electrical storage device that receives the portion of the voltage and the duration of voltage generation and a predetermined accumulated voltage of the second electrical storage device.
2. The electrically initiated inertial igniter of claim 1 , wherein the electrical energy generating device is a piezoelectric generator.
3. The electrically initiated inertial igniter of claim 1 , comprising a resistor connected to the first electrical storage device to drain a charge accumulated in the first electrical storage device resulting from non-firing events.
4. The electrically initiated inertial igniter of claim 1 , the circuit comprising:
a reset circuit; and
a comparator comprising:
a first input connected to the first electrical storage,
a second input connected to a reference voltage,
a third input connected to the reset circuit, and
an output that produces an indication of the all-fire condition in response to the predetermined accumulated voltage in the electrical storage device,
wherein the reset circuit is configured to reset the indication when the electrical energy generating device begins to generate a voltage.
5. A method for electrically initiating an inertial igniter for a munition, the method comprising acts of:
providing an electrical energy generating device to generate a voltage over a duration responsive to an acceleration of the munition;
providing a first electrical storage device connected to the electrical energy generating device through a voltage divide circuit to receive a portion of the voltage over the duration;
providing a second electrical storage device connected to the electrical energy generating device to accumulate the voltage; and
providing a circuit powered by a connection to the electrical energy generating device, the circuit determining an all-fire condition based on both a connection to the first electrical storage device that receives the portion of the voltage and the duration of voltage generation and a predetermined accumulated voltage of the second electrical storage device.