Power Supply - LeCroy Waverunner2 Series Service Manual

4.3

Power Supply

Do not touch any electric parts inside the power supplies during operation as the
primary side of the power unit has many high voltage portions to ground.
Input Voltages
The power supply supports a wide ranges of inputs, 90-132 V AC (45-440Hz) and 90-264V
AC (45-66Hz) are allowed.
Output voltages: 9 different DC voltages are available, +5Vd, +12Vd, +12V, and +27V,
+2.5Va, +5Va, -5Va, +12Va,–12Va.
Overview
The power supply unit consists of, roughly divided, Input Circuit, Input Filter & Rectification,
Power Factor Correction, Main Converter (for digital circuits) , Main Converter (for analog
circuits) and output regulators.
Power Switch
A power switch is located on the secondary side. In order to switch -on and -off all of the
outputs on the secondary side; the control is made by switching on and off the main
converter. When the power switch is off, some power is being fed to some components in
the power supply unit (stand-by mode) as long as the unit is plugged into an AC source.
Cooling
The power supply is designed to use forced air cooling with a fan. Operating the power
supply without a fan will cause the over-temperature protection circuits to trip because of
the temperature rise in the unit. When the protection circuit trips the power outputs will be
turned off.
4-18 Theory of Operation