SL150 MANUAL
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118093-001 REV B
4.2 High Voltage Transformer
The output of the High Frequency Resonant Inverter is
connected to the primary of the High Voltage
Transformer. The High Voltage Transformer is a set up
type.
4.3 High Voltage Assembly
The High Voltage Assembly typically consists of various
parallel, series arrangements of a full wave voltage
doubler.
Output filtering is typically provided by an R-C type
filter. Voltage feedback for regulation and monitoring is
provided by a high bandwidth resistive/capacitive divider.
Current feedback for regulation and monitoring is
provided by a sense resistor connected at the low voltage
end of the High Voltage Rectifier/Multiplier Circuit.
4.4 Control/Power PWB
The majority of control circuits for power supply controls
are located on the CONTROL/POWER PWB. +15VDC, -
15VDC, and +10VDC is generated on the
CONTROL/POWER PWB. High Voltage On/Off control
is accomplished by K3, and its associated circuitry.
Interlock control is provided by K4.
Voltage feedback from the high voltage divider is sent to
the control board via a mass terminated ribbon cable.
Gain adjustment is provided on the HV PWB. The kV
feedback signal is sent to the front panel DVM and to the
REAR PANEL D- CONNECTOR for remote monitoring.
K2 provides switching between feedback and program
signal for the front panel DVM’s. This allows the user to
preset the desired output before energizing high voltage.
Program voltages are typically ramped up to set level by a
slow start circuit.
An arc sense circuit provides sensing, quench and
indicator of arc conditions. Consult the operation manual
for a detailed description of the arc sense control.
Current feedback from the high voltage rectifier is sent to
sense resistors located on the High Voltage Assembly.
Calibrated feedback is then sent to the applicable circuitry
on the Control/Power Board.
U12 circuit provides visual indication of the control
mode, which is in operation. These signals are sent to the
FRONT PANEL ASSEMBLY for front panel status
indication.
The resonant control circuitry consists of a pulse width
converter. U17 generates all frequency and pulse width
control signals.
Power supply inhibit circuits are provided by U22 and
K3. System Fault control and Indication is provided by
U19 and associated circuitry. Diagnostic signals are
latched and then sent to the FRONT PANEL
ASSEMBLY for status indication.
4.5 Front Panel Assembly
Front Panel controls, meters and status indications are
connected to the FRONT PANEL PWB. The FRONT
PANEL PWB interfaces directly to the
CONTROL/POWER PWB.
4.6 Options
Due to the many variations of models and options
provided in the SL150, details of actual circuits used may
differ slightly from the above descriptions. Consult
Spellman’s Engineering Department for questions
regarding the principles of operation for the SL Series.
