Handbook of High Speed Photography - IET Labs, Inc.

3.4 THE TYPE 1540 STROBOLUME ELECTRONIC STROBOSCOPE.
The 1540 might well be considered a stroboscopic "floodlight."
Its high-intensity flash combines with a wide beam angle to effectively
illuminate both large-sized subjects and subjects that are in areas
having high ambient-light levels. Three control units are available to
permit either slaved, speed-measuring, x-synced single-flash-photo
graphic or delayed-flash motion-analysis operations. These control
units are described in paragraph 3.4.1.
The flash from the Strobolume provides about 20 times more light
output for any corresponding flash-rate setting than the Strobotac. The
1540 Strobolume is ideal for high-speed photography; for example, the
unit, at its highest flash intensity, has a guide number of 70 for High-
Speed Ektachrome (ASA 160). Auxiliary booster capacitors can be
added for even higher single-flash intensities. The beam angle can be
adjusted from a wide 7 x 13-foot pattern to a narrow 3 x 13-foot pattern
(at a 10-foot distance, see Table 4-1). The flashing rate of the 1540
can be adjusted continuously from a low of 30 to a high of 25,000
flashes per minute. Flash duration is 15 a*s, 12 jus, and 10 fjs on the
high-, medium-, and low-intensity positions.
The packaging of the 1540 Strobolume is unique in that the
power supply, control unit, and lamphead separate and cable connect
for applications requiring a remote light source. For one-hand opera
tion, the lamphead and control unit attach into a single integral unit.
Or, the lamphead can be conveniently mounted on a tripod, with or
without its control unit.
3.4.1 STROBOLUME CONTROL UNITS (Types 1540-P1, -P3, -P4).
Type 1540-P1 Strobolume Oscillator. This unit, Figure 3-5 (A), makes
the 1540 essentially a high-power Strobotac. Designed for speed meas
urements, the 1540-P1 features a calibrated flashing-rate control for
±1% measurements from 110 to 25,000 rpm. Speeds up to 250,000 rpm
can be measured by harmonic techniques. It can also be externally
triggered (see Table 2-3), has a trigger output, and a pushbutton for
unsynchronized single-flash photography.
Type 1540-P3 Strobolume Control Unit. Actually with this unit,
Figure 3-5 (B), the control of the Strobolume comes from an external
triggering source such as another stroboscope, 1537 Photoelectric
Pickoff, or a contacting mechanism. This unit makes the 1540 an ideal
slave light source for the Strobotac (when used with a 1531 Strobotac
a 1531-P4 Adaptor cable is required). Input requirements are listed in
Table 2-3.
23