1-9. Equipment Characteristics, Capabilities,
44.45 cm (17.50 in.)
12.4 cm (4.88 in.)
17.78 cm (7.0 in.)
a. Purpose of Converter:
Supplies regulated DC voltage to equipment
used in AN/TTC-38(V) and AN/TYC-39(V)
t e l e p h o n e switching systems.
b. Capabilities and Features:
above sea level
External shutdown capability, from equip
ment or control panel converter supplies.
Automatic shutdown in the event of overload
o r underload conditions.
21-30 volts direct current
Test points for monitoring output circuits.
of full load
0 to 10%
Ripple and Noise
10% to full load ±2%
1-10. Location and Description of Major
1-12. Safety, Care and Handling
All major components of the converter are located on
Observe all WARNINGS, CAUTIONS, and NOTES
the front and rear panels, and inside the main chassis
i n this manual. This equipment can be extremely
dangerous if these instructions are not followed.
1-11. Equipment Data
11.350 Kg (25 lbs. approximate)
1-13. Block Diagram Description
tion between input and output. The output voltage is
m o n i t o r e d by the control circuits which, in turn, ad-
just the pulse width (duty cycle) of the 20 kHz
a. Two connectors (P1 and P2) are provided for
switching regulator automatically so that the output
dual input and output connections. The outputs are
voltage is maintained independent of the input line or
interconnected to the loads through isolation diodes
o u t p u t load conditions.
which enable two or more converters to be used in
c. The input EMI filter prevents electromagnetic
redundancy. If one converter fails, the standby con-
i n t e r f e r e n c e s generated in the switching converter
v e r t e r will automatically take over without voltage
from reaching the input DC line and similarly pre-
i n t e r r u p t i o n (glitching) at the load. Two converters
v e n t s electromagnetic interference on the DC line
m a y be used to supply a single load or three con-
from reaching the regulated output voltage. The unit
verters may be used to supply two independent
is also protected against damage if a reverse input
loads. In this case, the third converter stands by and
voltage is applied by a large reverse rectifier directly
w i l l take over if either of the two converters fail.
across the bus. The capacity of this rectifier is suffic-
I n p u t voltage may vary between 21 and 30V with
ient to trip the system circuit breaker without dam-
age to the converter.
b. The converter contains a 20 kHz pulse width
m o d u l a t e d DC-DC converter with transformer isola-