Igniter/Squib Circuit Testers

Raptor Scientific is a designer and manufacturer of igniter circuit testers approved by the US Department of Defense for failsafe measurement of the resistance and stray voltage in the multiple electrical circuit paths leading to critical components, like explosives, missiles, or rocket ignition.
Our igniter testers come in single-channel and multi-channel models for testing simple electronics paths to complex multi-path circuits.

Theory of Operation of Igniter Circuit Testers

Basic Circuit - All of our instruments use the same fundamental concept, illustrated for the 20 ohm range in Figure 1. The voltage drop across the unknown resistor (R) is measured via a true differential amplifier. Current through the unknown resistor is determined by measuring the voltage drop across a precision resistor in series with the unknown. The Ohm's Law calculation is then performed by a ratio circuit and the result displayed on a LCD digital panel meter.
Figure 1 - Basic Concept for 20 Ohm Range
Figure 1 - Basic Concept for 20 Ohm Range

Fail-Safe Current - Figure 2 illustrates what the instrument circuit is reduced to in the event of the worst-case failure of all active components. A failure of the regulator applies the full battery voltage across the series combination of 1.24K resistor and (R). Assuming the part to be less than 1 ohm, the fail-safe current is 8 mA.

Figure 2 - Circuit After Worst Case Failure
Figure 2 - Circuit After Worst Case Failure

Fail-Safe Module - To prevent anyone from bypassing the critical fail-safe circuitry, it is sealed in a potted module attached directly to the output connector. This module will continue to limit test current even if the instrument is dropped on a concrete surface from a height of 100 ft.

Charger Interlock - The AC charger must be unplugged in order to connect the test leads, making it impossible for a test to be run with the AC still connected.

Sealed Battery - We use a special re-chargeable nickel metal hydride battery pack which is totally sealed in a thick plastic case to guard against leakage and has an output connector which does not match any off-the-shelf battery of higher voltage. A fuse inside the case protects the instrument in the event of a short circuit.

Extensive Testing - The instruments are subject to a series of environmental and performance tests, ensuring both accuracy and reliability.

Built-in mA Meter - A milliamp meter mounted in the cover of the instrument verifies that test current is within safe limits before attaching the leads to the part.

Military Approval - Our instruments have been approved by the military as safe for testing electro-explosive devices.

OTHER INSTRUMENTS - We make custom and computer programmed production versions of these testers. Contact our sales department.

Igniter/Squib Circuit Testers


1n-SQB-RUG Ruggedized Squib Tester
1n-SQB-RUG Squib Tester View Product
Multi-Test Point Igniter Tester View Product
Two-Channel Igniter/Squib Tester View Product
Rack-Mounted Single Channel Igniter Circuit Testers View Product
Portable Single Channel Igniter Circuit Testers View Product

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