Comdel CX600 Series, Manual

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Upon receipt of this ASCII character the CX will disable RF power, set the power
setpoint to zero, issue a "<CR><LF>BYE" response, then redirect control of the CX to
the mode the unit was previously in when the attention command (!) was given. Local
control can now be commanded from the front panel mode select button.
This command only functions after a PROMPT and does not require a carriage return.
The '#' will not be recognized buried in or tagged at the end of another command.
The CX will no longer recognize serial port ASCII characters EXCEPT for the attention
'!' character.
VII. Theory of Operation
The CX600/13.56 is a high frequency power amplifier for use in OEM applications. The power sources consist of a AC
Interlock, DC power supply, five stages of gain with associated control systems and monitoring circuits.
The radio frequency signal is generated locally in the Oscillator Control Module. From this module the signal goes to
the driver. The driver further amplifies the signal to approx. 20 Watts to drive the PA600 power amplifier. From the
PA600 the signal is fed through a low-pass filter to remove harmonic content. Forward and Reflected control signals
are obtained from the output signal as it passes through the power monitor board to the o utput RF connector. The
front panel CX Controller monitors the user input from either the front panel or rear connector, and monitors the control
signals from the RF output power monitor, PA voltage monitor, PA current monitor, and PA overtemp switch. Refer to
Fig 1, CX600 BLOCK DIAGRAM to see how the individual modules are connected together.
A. AC Interlock PCB
The AC mains to the mains power transformer is switched via relay K1, controlled by the AC INTERLOCK
PCB (Figure FA0900RX) mounted on the front panel behind the ON/OFF softkeys. AC power to this interlock
system is supplied by 24VAC transformer which is energized when circuit breaker CB1 on the back panel is
thrown.
The AC INTERLOCK PCB supplies the logic to the AC mains control contactor to start and stop the CX600
via the front panel softkeys. The PCB's start/stop circuitry is composed of relay logic for safety. The active
circuitry (U1A) causes the OFF softkey lamp to flash if the interlock loop is broken.
The interlock 'loop' for the CX600 includes the rear panel I/O 15 pin 'D' connector, the top cover, and the RF
output connector cover.
B. DC Power Supply
The DC supply consists of a single -phase transformer, full-wave, bridge rectifier and a low-pass filter for the
main power voltages. There are three single-phase bridge rectifiers and filters feeding the positive 15 volt,
negative 5 volt, and positive 5 volt regulators. These voltages are used in the control circuitry.
The outputs of this stage are:
1 44 VDC Unloaded
37 VDC 25 amps (600W RF output)
1 +15 VDC Regulated 250 mA max
1 -5 VDC Regulated 250 mA max
1 +5 VDC Regulated 1A max