Tests indicate that electric detonator simulators of the exploding bridgewire type will not fire as a result of the application of a direct current power of one watt for 5 minutes. The detonator also will not fire if the protective gap fails and the firing stimulus is inadvertently applied

Sullivan, R. R.

Tarley, R. C.

Tarpley, R. C.

English

NASA Technical Reports Server

Main Charge 
Acceleration Bridgewire	
Charge 
Insulator	 Case 
Seal
Sleeve 
.
Electrical-d
' U Body A [ - - I 
Pins
B L__J 
Internal Construction of the EBW Detonator Simulator 
Tests of the EBW (exploding bridgewire) detonator 
were conducted in which an electric detonator simu-
lator was used. New data on the physical characteris-
tics and explosive reactions of typical EBW detonators 
for increasing amperages were obtained. Basic data 
such as bridgewire action, explosive output, and test 
circuitry were also generated. 
One hundred detonator simulators with the same 
critical design characteristics as the EBW detonator, 
except for the spark gap, were used in a series of tests. 
No-fire tests were conducted on the simulators using 
one-ampere, one-watt, or increased amperage (5 to
December 1969	
Brief 69-10782 
NASA TECH BRIEF 
.	 - 
NASA Teèh Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Exploding Bridgewire Detonator Simulator 
100 amperes) as the test stimuli. All units withstood 
their respective stimuli for 5 minutes without firing. 
When a high-voltage, high-energy pulse is applied 
to a small wire resistance element, the wire explodes 
with a rapid release of large amounts of energy. This 
energy initiates a train of chemical explosives in the 
EBW detonator. The final component of the train 
(output charge) is a small charge of high explosives 
which produces a high-velocity shock wave that can 
detonate another explosive device. Thus, the EBW 
detonator can initiate, on command, the explosive 
components of a rocket stage. 
The test unit (see figure) is configurated on one end 
with two electrical pins and has a hexagonal center 
section and a cylindrical end case that contains the 
explosive train. A series electric circuit consisting of a 
wire-resistance element, or bridgewire, is contained 
in the test unit. 
The detonator simulator has bridgewire resistance, 
pin spacing, explosive train, and heat sink properties 
identical to those of the EBW detonator and was 
designed specifically for these tests, since actual EBW 
detonators could not be used. The functional charac-
teristics of the protective spark gap in the detonator, 
which would have blocked the application of current to 
the bridgewire, precluded the use of actual EBW 
detonators in the tests. 
The tests described in the report mentioned below 
demonstrated that the EBW detonator simulator will 
not fire as a result of the application of one ampere for 
5 minutes and/or the applicaiion of a direct-current 
power of one watt for 5 minutes. The tests also showed 
that the EBW detonator will not fire if the protective 
gap fails and the firing stimulus described is inadver-
tently applied.
(continued overleaf) 	 --
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19690000660 2020-03-16T18:34:04+00:00Z
Notes: 
I. Additional information is available in "One-
Ampere, One-Watt, No-Fire Demonstration of the 
Electric Detonator, Exploding Bridgewire Type, 
Douglas Specification Control No. 7865742-I, 
Model No. Saturn S-IV," Douglas Report SM-
46868, September 1965. 
2. The information may be useful to those using ex-
plosive and explosive safety devices. 
3. Requests for futher information may be directed to: 
Technology Utilization Officer 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference B69-10782
Patent status: 
Inquiries about obtaining rights for the commercial 
use of this invention may be made to NASA, Code GP, 
Washington, D.C. 20546. 
Source: R.R. Sullivan and R.C. Tarpley of

Douglas Aircraft Company, Inc.

under contract to

Marshall Space Flight Center

(MFS-02 191)
C 
Brief 69-10782	 Category 01


Exploding bridgewire detonator simulator

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server