MAGNET POWER SUPPLY SYSTEM 9100
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DANFYSIK A/S - DENMARK.
4.3.3 ADC Control
Different voltages are monitored by means of the Analogue to Digital converter U706. The
measured values and their resolution are shown in the table below.
The 2.5V reference voltage for the ADC converter comes from U707.
VALUE BIT RESOLUTION
Output current 16
Current Setting 16
Output Voltage 16
Field measure 16
For monitoring of power supplies +15V, -15V, +5V and Peltier control output voltage, the
internal ADC of the CPU U212 is used. The bit resolution of the internal ADC is 10 bit.
4.3.4 Voltage reference
The voltage reference circuit is constructed around U707 “MAX6325” which delivers 2.5V
high precision voltage to the ADC “U706”.
U704 is the 10 V high precision voltage reference for the DACs U701, U702 and U705.
4.3.5 DC/DC Converter
A small buck switch regulator U101 converts the +15 V to +5 V for the digital circuits.
The buck switching regulator is an LT1765 from Linear Technology.
The linear regulator LM78L05 U709, regulates +15 V to +5 V for the analogue circuits.
For supplying of RS232/422/485 interface, transformer drivers for isolated serial interface and
low-dropout voltage regulator are used. Transformer drivers have references U102 and U104
for remote and local line respectively. Low-dropout voltage regulators have reference U103
and U105 for remote and local line respectively.
4.3.6 Serial Interface
The SYSTEM 9100 supports the serial communication standards RS232, RS422 and RS485.
The default setting is RS422.
The serial communication circuit consists of U321, U326, U328, U329, and U334. This circuit
is fully galvanic isolated from other circuits in the supply but not between each other.
The connectors “REMOTE CONTROL” “LOCAL CONTROL” are the serial interface ports
on remote and local line respectively. Please refer to chapter 3.3.2 about pin description for
these serial line connectors.
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