Handbook of High Speed Photography - IET Labs, Inc.

section 3
GENERAL RADIO
STROBOSCOPES
3.1 THE TYPE 1539STROBOSLAVE® ELECTRONIC STROBOSCOPE.
3.1.1 GENERAL DESCRIPTION. The Type 1539 Stroboslave (Figure
3-1) is a miniature electronic stroboscope. The Stroboslave satisfies
the basic requirements for motion studies and high-speed photography,
but is not suitable for tachometry as it has no internal oscillator. Its
reflector-lamp assembly is connected to the case by a five-foot exten
sion cable so that the lamp can be used either attached to the case or
conveniently positioned over the subject, even in cramped spaces. The
reflector can be removed so that the strobotron lamp assembly can be
inserted through a hole as small as one inch in diameter to observe ob
jects in otherwise inaccessible areas (see Figure 3-2). When the re
flector is in place, the light output is concentrated into a long-throw
10-degree beam (measured at one-half-peak-intensity points) with an
apparent source 18 inches behind the reflector front. For further, more
specific information on the photographic characteristics of the 1539 as
a light source with and without reflector, refer to Section 4. The Stro
boslave has the same high maximum flash repetition rate, short flash
duration, and the same light characteristics as the 1531 and 1538 Stro
botac electronic stroboscopes.
3.1.2 TRIGGERING THE STROBOSLAVE. The Stroboslave can be
triggered by the closure of a switch across its input terminals or by a
positive voltage pulse of at least 2 volts peak amplitude. The Strobo
slave can therefore be triggered by the output pulse of the 1538 Strobo
tac, the 1531 Strobotac through a 1531-P4 Trigger Cable, the 1531^P2
Flash Delay, or by the 1537 Photoelectric Pickup. (A table showing
all possible interconnections of the various General Radio Stroboscopic
instruments is given in Section 5.) This multiplicity of trigger possibil
ities, along with its small size and low cost, make the Stroboslave a
most convenient and economical instrument for a variety of applications.
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