TM 55-1930-209-14&P-12
1.1.3
transistor Q7 collector to Q8 collector. The transformer T2 is an auto transformer with a ratio of 1.42:1,
therefore its output voltage will be about 28 V AC.
1.1.4
Program Timer
See drawing M-1331-C, Diode D1 and transistor Q1 provide a regulated input to the timing circuit. The
timing circuit consists of a basic unijunction "clock" circuit (R3, R5, C2 and Q2), "clock" pulse amplification
(Q3 and Q8), digital counting circuits (IC1, IC3), and logic readout (IC2), and final signal amplification to
output. Note remote control point at terminal "3". Closing a contact between this point and negative will
hold the signal "off". Terminal 5, on the timer board is used only for initial timing, or for subsequent timing
checks with an electronic counter by “reading" across this terminal and negative.
2.0
Installation
The fog horn must be mounted base down as shown in the dimension drawing S-4369-C. Power is obtained from a
nominal 12 volt direct current source such as a battery, the capacity of which should be adequate to deliver the 2
amperes average blast current for the desired service period. Normal battery voltage is 12 volts.
The fog horn is furnished with a 2 wire power supply cable. As directed on the decal on the side of the fog horn,
the black lead should be connected to the positive (plus) side of the battery and the white lead to the negative (minus)
side.
Form No. 6310 0238
ix
