An initiator including a housing adapted to be received in an igniter or rocket motor, at least one charge at a distal end of the housing, an electro-explosive device behind the charge for detonating the charge when subject to a voltage HV, and a pressure bulkhead behind the electro-explosive device. An electronic subsystem in the housing is connected to the electro-explosive device through the bulkhead and includes a lead for providing the voltage HV to the electro-explosive device to initiate it, and a switch in the lead which does not conduct if errant voltages are present on the lead to prevent initiation of the electro-explosive device until the correct voltage HV is present.
1. An initiator comprising:
a housing adapted to be received in an igniter or rocket motor;
at least one charge at a distal end of the housing;
an electro-explosive device behind the charge for detonating the charge when subject to a voltage;
a pressure bulkhead behind the electro-explosive device, and
an electronic subsystem in the housing connected to the electro-explosive device through the bulkhead and including:
a lead for providing the voltage to the electro-explosive device to initiate it, and
a switch in the lead which does not conduct if errant voltages are present on the lead to prevent initiation of the electro-explosive device until the correct voltage is present.
2. The initiator in claim 1 in which there are two charges in the distal end of the housing.
3. The initiator of claim 2 in which one charge is a pyrotechnic material and the other charge is a detonating material.
4. The initiator of claim 3 in which the pyrotechnic material includes BKNO.sub.3 and the detonating material includes HNS-IV.
5. The initiator of claim 1 in which the electro-explosive device is an exploding foil initiator.
6. The initiator of claim 1 in which the switch is a spark gap.
7. The initiator of claim 6 in which the electronic subsystem further includes a resistance in series with the spark gap for limiting current.
8. The initiator of claim 6 further including a capacitance charged by a voltage on the lead.
9. The initiator of claim 7 further including a resistance in parallel with the capacitance.
10. An initiator comprising:
a housing adapted to be received in an igniter or rocket motor;
at least one charge in the distal end of the housing;
an electro-explosive device behind the charge for detonating the charge when subject to a voltage;
a pressure bulkhead behind the electro-explosive device, and
an electronic subsystem in the housing connected to the electro-explosive device through the bulkhead and including:
a lead for providing the voltage HV to the electro-explosive device to initiate it, and
means for preventing errant voltages from initiating the electro-explosive device.
11. The initiator of claim 10 in which said means includes a spark gap.