BRUEL & KJAER 2663, Техническая документация инструкция

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Chapter 2 — Operation
Output and Supply Connections
Preamplifiers Types 2663 and 2663 B
User Manual
BE 1068 – 12
11
2.4.1 Output Signal – Pins A and B
Pins B and A provide the AC output signal and DC output signal respectively. The
maximum output signal voltage available at the preamplifier output socket is 7 V
peak-to-peak with a maximum output current of 5 mA. The output is short-circuit
protected and has an output impedance of 50

. This enables the use of relatively
long output connection cables without their shunt capacitance influencing the useful
frequency range available for measurement.
The output bias is preadjusted to 2.5 V and is adjustable from 0 to +5.5 V referred to
supply ground (+0.5 V to +5.5 V for single supply).
2.4.2 Overload Detector – Pin D
The overload detector signal is output through pin D. It contains five inputs from
different stages of the preamplifier circuit and is pulled high on overload.
This could, for example, be used to drive the event marker of a level recorder and
can be used in systems for remotely recording or monitoring vibration signals.
2.4.3 Signal Ground Connection – Pin C
The signal/ground signal is output via pin C. Since the 0 V line of the supply is part of
the measurement system signal ground line, it should only be grounded via the chas-
sis of the readout. If connected to the supply chassis, then the signal ground line
should be disconnected from the readout chassis to prevent the formation of a
ground loop. To keep radiation pickup to a minimum, the signal line of the readout
should be connected to its chassis and the supply chassis should be connected to
the earth of a mains supply.
2.4.4 Power Supply – Pins C, E and F
Power is provided to pins E and F by a dual-polarity DC supply with voltage between
±20V and ±32V (see
Fig.2.7 ), or by a single-polarity DC supply, between pins C and E
with voltage b20 V and +32 V (see Fig.2.8 ).