Comtech EF Data RSU-503 - Manual (Page 42)

Rev. 8 3–1
3
Chapter 3.
THEORY OF OPERATION
This chapter provides the basic theory for the following:
•
Switch power
•
Waveguide and coax switch drivers
•
LNA
•
M&C operational control
3.1 Power
In a redundant system, the switch is powered from either of the two RFT terminals via
the M&C interconnect cable. External DC power (approximately 10.8V) enters the M&C
on pins 1 and 2 of connector J17 (25-pin D), and is “ORed” through diodes CR1 and
CR2.
The switch is monitored by the analog-to-digital (A/D) converter U16, and is made
available as a maintenance status through the serial terminal.
A 3-terminal regulator, U1, converts and regulates the +5V to all the logic, including the
microcontroller U18.
PS1 converts the 10V input voltage to 30V, where it is stored by capacitors C6 through
C10 to supply the 500 millisecond pulses to the transfer switches.