Handbook of High Speed Photography - IET Labs, Inc.

Type 1540-P4 Oscillator/Delay Unit. The ideal control for mo
tion analysis and high-speed photography, this unit, Figure 3-5 (C),
has a delay circuit much like the 1531-P2 (see paragraph 5.3.1). An
amount of time delay adjustable from 100 fis to 1 s can be inserted into
the triggering circuit to delay the time at which an external input sig
nal will flash the 1540. This permits phasing of the flash with the mo
tion of the subject to allow both visual and photographic analysis in a
point-by-point manner. An input is provided for cameras having X-sync,
for both delayed and nondelayed synchronized single-flash photo
graphy. The 1540-P4 will accept a variety of input trigger signals (see
Table 2-3). One unique feature not found in other GR stroboscopes
bears mentioning. When the 1540-P1 is used with photoelectric pickoffs,
it can be made to trigger from either a reflective or nonreflective
mark. This is described in paragraph 5.2.3. In addition, the 1540-P4
has an adjustable uncalibrated oscillator for varying flash rate from 30
to 25,000 flashes per minute. A pushbutton is also provided for burstflashing
the 1540 for multiple-exposure photography.
Figure 3-5.
The Type 1540 Strobolume and Control Units.
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