III OPERATION 
The basic single ended or dual ended 
data cameras are highly versatile and can be 
applied with various electronic systems for 
sequential read out. This section describes a 
particular type of circuitry which allows up to 
12 separate sensors to be sequentially read out 
on meters. 
A. Circuitry 
The camera is driven by a d-c motor 
which serves two purposes: it advances the 
film and drives a 6-position selector switch 
which sequentially reads out the various instru- 
ments. 
For a 12-instrument sequential read 
out, a meter is placed at each end. The two ends 
of the data camera take pictures of the meters 
at either end simultaneously. At the same time, 
a small indicator light at one end of the camera 
will indicate in the picture which instruments 
are being read out. For example, instruments 
No. 1 and 7 are read out with the No. 1 indicator 
light on, and instruments 2 and 8 correspond to 
the No. 2 indicator light, etc. Each time the 
film is advanced one frame, the selector switch 
is moved to a new position to read the next two 
instruments in sequence. The selector switch is 
mounted on top of the film advance socket 
mechanism as shown in Figure 1. A sample of the 
data picture is shown in Figure 2. 
INDICATOR 
LIGANTS 
(as pp ROTARY 
SELECTOR 
Sample film strip from dual ended data 
camera. 
Figure 2. 
The camera is activated by momentarily 
grounding the power lead to the 6 volts d-c 
supply. Each time this occurs, three separate 
circuits operate on the camera: (See Figure 3) 
1) the data lamp capacitors (C,) dis- 
charge through the incandescent bulb (B,) ex- 
posing the data chamber frame, 
2) the indicator light capacitors (Cs) 
discharge through the indicator bulbs in the end 
cap to show which instrument is being read out. 
WATERPROOF 
POWER PLUG 
( swircw 
@ A 
g eames aim 
< J 
S > | 
> TIMER 
SwW/ TCH 
N2 
DATA ie 
( LAMP 
82 
be = 
-— aa 
ey. 
= CAT. 
COAXIAL 
CONNECTORS 
COAWEC TOR 
B0ARO 
Fig. 3 Data Camera Circuit Diagram 
89 
