Grounding Considerations; Power Supply Requirements; Power Dissipation; Fusing - HP 5501B Operating And Service Manual

Observe the current and grounding requirements described below.

2-23. Grounding Considerations

2-24. In order to avoid ground loops, the laser head base should be the only connection to earth
ground. To accomplish this, the outputs of the ±15 Volt power supplies used to power the laser
head should be floating. The +5 Volt power supply output required for either the HP10740A
based electronics or HP10781A Pulse Converters, should also be floating. Alternatively, any
other single point earth ground connection can be used to satisfy grounding requirements.

2-25. Power Supply Requirements

2-26. Table 2-2 lists the supply voltages, currents, and tolerances required by the HP5501B Laser
Head. Note that other components of the system also use ±15 Volts. Add these to the laser
head current requirements to obtain the overall system requirements.
Supply Voltage
+15 Volts
-15 Volts

2-27. Power Dissipation

2-28. The HP5501B dissipates approximately 21 watts during operation.

2-29. Fusing

2-30. The HP5501B has two internal 1.5 Ampere fuses to protect the ±15V lines. Both fuses are
located on the A1 Connector Board and are accessible by removing the left and right covers of
the laser head.

Table 2-2. HP 5501B Power Supply Requirements

Tolerance
±0.3 Volts
±0.3 Volts
Other Power Supply Requirements
Line Regulation
Load Regulation
Ripple + Noise
Isolated Output
Over Voltage Protection
(Recommended)
Under Voltage Protection
(current limited)
(Recommended)
Current Requirement
0.8 Amperes
3.5 Amperes peak surge for
approximately 2 milliseconds
at power-up
0.7 Amperes
0.01%
0.01%
60 millivolts peak-to-peak
HP5501B
Installation
2-7