Electric Initiators

Key Features

Electric Initiator Design Guide

How an Electric Initiator Works

An electrical input is applied to the electric initiator, heating a small wire, called a bridge wire, which is in contact with the pyrotechnic. The wire quickly heats to the auto-ignition temperature of the pyrotechnic or explosive material. The pyrotechnic material then reacts providing gas pressure and/or flame. The heat and flame can be used to ignite other explosives or propellants while the gas pressure can be used to perform work.

Configuration Envelope

• Output Thread Size
• Mating Connector
• Overall Length
• Total Mass
• Connector Pin Quantity
• Number of Circuits
• Pin Grounding to Body
• Ground to Cable Shielding
• Cable Definition/Shielding

Environment Capabilities

• Max Temperature
• Max Shock Levels
• Max Vibration Levels
• Acceleration Limit
• Max Storage Temperature

Electric Properties

• Insulation Resistance
• Dielectric Withstanding Voltage
• Circuit Resistance
• Electrostatic Discharge (ESD)

Ignition Considerations

• Firing Current (AC-DC)
• Constant Current
• Capacitance Discharge
• Low Voltage Ignition
• High Voltage Ignition

Performance Characteristics

• All-Fire Capability
• No-Fire Capability
• Pressure Output
• Time to Peak Pressure
• Pressure Retention Limits
• Cable/Pin Pull Strength

Common Design Criteria and Test Method Defining Documents

• MIL-DTL-23659 Detail Specification Initiators, Electric, General Design Specification
• AIAA S-113 Criteria for Explosive Systems and Devices on Space and Launch Vehicles
• RCC-319 Flight Termination Systems Commonality Standard
• MIL-HDBK-83578 Criteria for Explosive Systems and Devices on Space Vehicles
• MIL-STD-1901A Munition Rocket and Missile Motor Ignition System Design, Safety Criteria
• MIL-STD-810  Environmental Engineering Considerations and Laboratory Tests
• MIL-STD-1516 Electro-explosive Subsystems, Electrically Initiated Design Requirements and Test Methods
• MIL-STD-331 Fuze and Fuze Components, Environmental and Performance Tests
• MIL-STD-202 Test Methods for Electronic and Electrical Component Parts
• MIL-STD-464 Electromagnetic Environmental Effects, Requirements for Systems

~ Some of the noted documents are cancelled for new designs but are still readily used in the industry. ~

Applications

PacSci EMC has designed, manufactured, and qualified hundreds of Electric Initiatorss for use on multiple platforms for commercial and military aircraft, missiles and munitions, space and launch vehicles, and deep underground oil field applications. We are currently in production of an initiator line that was qualified in 1976 and has been in continuous production since. Many versions are in stock and available for immediate delivery.

A few applications include: aircraft seat ejection, aircraft fire extinguishing, oil and gas well perforating, demolition, launch vehicles, satellites, missiles and munitions, parachute release and electrical circuit breakers.

Specifications

• All-Fire, Typical
  3.5 amps at 0.999 reliability at 95% Confidence level
• No-Fire, Typical
  1.0 amps / 1.0 watt, 0.001 probability to fire at 95% lower confidence
• Operating Temperature Ranges
  As low as -420°F for PacSci EMC’s Space Initiator
  AS high as +400°F for PacSci EMC’s GreenDet™
• Ordnance Output
  Deflagration – Tailored peak output pressure performance
  Detonation – Tailored dent depth in steel or Al dent block
• Electrostatic Discharge, Typical
  25 kVDC from a 500 pF capacitor with a 5000 ohm series resistor

Applicable Standards

• MIL-DTL-23659 Initiators, Electric, General Design For; Appendix A: In-Line Initiator Certification
• MIL-STD-1512: Electro-explosive Subsystems, Electrically Initiated, Design Requirements and Test Methods
• DOD-E-83758: Explosive Ordnance for Space Vehicles, General Specification for
• RCC-319: Range Commanders Council Flight Termination Systems Commonality Standard
• MIL-STD-1576: Electro-explosive Subsystem Safety Requirements and Test Methods for Space Systems

Interface

Many features, such as the connector, thread, length, single or dual bridgewire, output, and other features can be customized to meet customer applications.

FAQ's

• What does bridge wire mean?

  A small wire that transfers energy.