MAGNET POWER SUPPLY SYSTEM 9100
56
DANFYSIK A/S - DENMARK.
4.6
Output module
This block is the power stage where the output current is generated.
4.6.1
Output and filter
In order to ensure a stable output current some capacitors (C9, C11, C12 and C13) and a choke
(Lcom) are placed at the output stage.
4.6.2
Transformer
The ferrite power transformer T2 is wound on an ETD 59 coil form and is designed with
minimum creepage of 8 mm from primary to secondary windings.
Three layer of high temperature isolation material is applied between primary and secondary
windings.
Resistive loses and loses from high frequency skin depth effects are reduced to a minimum by
use of 0.1 mm isolated copper foil in the primary and the secondary windings and interleaving
the windings.
4.6.3
PWM controller
The PWM controller module is built around U2, a phase shift PWM controller from Unitrode.
4 PWM signals (A OUT, B out, C out and D OUT) is wired to the output module where the
output current is generated.
4.7
Aux power supply
The aux power supply module delivers the supply voltages for control board and other modules
connected to it. The different supply voltages are for CPU, fans, digital and analog circuits as
these don‟t operate at same supply voltage.
4.7.1
AC line monitor
The AC input line is monitored and the system will go in fault mode in case of malfunction at
the AC line.
Monitoring of the AC line is built around Q1, Q2, Q3 which measure the voltage across the
three-phase line input and send an error signal via U1, U4 and U7 to the „AC Line OK‟ which
is connected to the I-loop control board.
4.7.2
Aux power loop & CPU
This circuit regulates different voltages for supplying of the microprocessor CPU and the I-
loop control board.
The different voltage supplies are regulated by U5 and U12 and a transformer T2.
Available supply voltages are +15 Vdc, -15 Vdc, +12 Vdc and +5 Vdc.
