5
XLB-3000 Theory of Operation
(Refer to Figure 1)
The XLB-3000 Xenon lamp ballast has been designed for OEM Xenon lamp industry.
With this in mind, the Xenon lamp industry has the following requirements:
•
Safe lamp operation
•
Reliable short pulse lamp ignition
•
Compact size
•
Power factor correction to conform with CE requirements
•
Low conducted electromagnetic emissions
•
Low leakage for medical applications
Referring to Figure 1, the XLB-3000 BLOCK DIAGRAM. The following is a brief
description of operation.
AC Input Power Circuitry
AC input power is processed through a line filter to reduce the conducted EMI to an
acceptable level. The XLB-3000 line filter has minimum capacitance to ground to
minimize leakage currents.
Power Factor Correction Boost Inverter
The rectified input power is next applied to power factor boost inverter. This inverter
boosts the input voltage to 400VDC. In the process of boosting the input AC voltage, the
input AC current is adjusted so that is always in phase with the input AC voltage.
Without this power factor correction circuit, the AC input current would be delivered to
the power supply in high amplitude, narrow spikes, having a high harmonic content. With
power factor correction, the non-50/60 Hz harmonics are reduced to near zero. Since only
the fundamental frequency is now used to deliver power, the efficiency of the power
supply is improved considerably.
One problem with standard input power factor correction circuits is that a high frequency
switching circuit is placed across the line in the input side of the traditional input capacitor
filter. This circuit results in substantial switching noise conducted to the line. Lumina
Power employs a proprietary soft-switching boost inverter which produces minimum
switching noise, reduces switching losses, and results in a smaller heat sink associated
with the power factor circuit.
Zero Voltage Switching (ZVS) Inverter
The ZVS inverter and the output transformer are used to step the 400VDC bus down to
the appropriate output value. The ZVS inverter is the most modern high frequency/low
loss/low noise topology utilized in power electronics today. Instead of running the
inverter in a traditional PWM mode, the inverter is run in a phase shift mode. With the
appropriate output inductor and the appropriate capacitance across each switching device -
in this case MOSFETS - there are virtually no switching losses in the inverter. The only
losses in the devices are I
2
R losses associated with the Drain/Source resistance of the
Summary of Contents for XLB-3000
Page 1: ...1 USER MANUAL XLB 3000 Short Arc Xenon Lamp Ballast...
Page 8: ...8 Figure 2 XLB 3000 Chassis Outline Drawing For 3 D model consult factory...
Page 9: ...9...
Page 11: ...11 XLB 3000 XX YY Interface Schematic Figure 4...
Page 13: ...13 NOTE Negative ignition is also available Figure 6 XLB 3000 Lamp Connections...
