Comdel CPS-1001/S/13.56MHZ, Operator'S Manual

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B. Remote Control Operation
1. To control power remotely, a positive DC voltage must be applied to Pin 5 of J1 (Pin 6 is
the return.) Control voltage of 0 to 10V yields an output of 0 to 1000 watts. Voltages put
on this pin exceeding 10 volts will produce higher power up to a point. However, warranty
of the unit cannot be maintained if the unit exceeds its design rating of 1000 watts.
2. Forward and reflected power can be monitored remotely through Pins 3 and 2 respectively
(Pin 6 is the return). Forward power is related linearly to 0 to 5 VDC corresponding to 0
to 1000 watts. Reflected power relates 0 to 5 VDC linearly to 0 to 1000 watts. (Optional
0 to 10 VDC may be chosen for full scale power monitoring.)
C. Test Equipment List
Instrument Type
and Cables
Min. Req. Spec Recommended Instruments
and Accessories
50 ohm Coaxial Resistor 1500W dissipation Bird Electronics Thermaline
coaxial Resistor #8860
Water Chiller 25-30 degrees C.
1.5 GPM min Neslab Cool Flow
Refrigerator Recirculator
Model CFT-33XW
VII. Theory of Operation
The CPS-1001/S/13.56MHZ is a high frequency RF generator. The power source consists of three DC
Power Supplies, oscillator control board, driver, power amplifier, directional coupler and integrated meter
assembly. Schematic diagram dwg# FP0213RI is a compete system drawing down to the module level.
A. DC Power Supply (schem dwg# FP0213RI)
The DC supply consists of a three-phase transformer, a three phase full-wave, bridge rectifier,
and low-pass filter for the high current DC power supply. This supply is used primarily by the
driver and power amplifier (PA). There are two regulated low current power supplies. Both
are on the integrated meter assembly printed circuit board (+/- 15VDC). The +/- 15VDC
supplies are used in the oscillator control board (OCB) and on the integrated meter board.
The outputs of this stage are:
1 50 VDC max. Unloaded
41 VDC Loaded (1000 watts RF output)
1 +15 VDC Regulated 250 mA max.
1 -15 VDC Regulated 150 mA max.
B. Oscillator Control Board (schem dwg# FA0401RE)
The oscillator is a hermetically sealed crystal circuit clock oscillator with a frequency stability
of .01%. The signal from the oscillator is buffered and amplified by two stages of gain. This
signal is now fed into the OCB output stage. The output is a class “C” amplifier stage. Output
power of this stage varies from 0 to 1.0 watts by changing VCC. The VCC is changed via the
ALC (automatic level control) circuit. There are no trimming or adjustments required in the
RF part of the circuit due to its broadband and low “Q” matching networks.
The automatic level control (ALC) circuitry smoothes output power control and stabilizes
output power against line and load variations. Control is achieved through the MC34082