1
This instrument produces voltages that can be
hazardous. Always have power switched off
before connecting or removing cables to or from
the 428 and the units to which its high voltage
outputs are applied. Observe the same
precautions when using the test points for any
purpose.
ORTEC MODEL 428
DETECTOR BIAS SUPPLY
1. DESCRIPTION
The ORTEC 428 Detector Bias Supply provides bias
voltage of either polarity for two semiconductor
detectors. The voltages are selected independently
by 10-turn, direct-reading potentiometers. The
polarity is controlled by a front panel switch. Jacks
are provided on the front panel for external
monitoring of the current in each detector. The
output of the 428 is short-circuit proof and has an
impedance of approximately 1.3 M
Ù
. The 428 is a
double-width module designed to meet the
recommended standards outlined in DOE Report
TID-20893 (Rev.). It receives the necessary
operating power from the ORTEC 4001/4002 Bin
and Power Supply through the rear module
connector.
WARNING
2. SPECIFICATIONS
PERFORMANCE
NOISE AND RIPPLE
<0.0002%
TEMPERATURE STABILITY
0.03%/
E
C, 0 to
50
E
C.
LINE STABILITY
Directly proportional to dc power
supply stability (<0.02% for 105 to 125 V ac when
using ORTEC 4002A).
CONTROLS
BIAS CONTROLS (A and B)
10-turn direct-reading
potentiometers.
POS/OFF/NEG
Front panel switch to control bias
polarity. Off position provides standby condition for
the power supply.
OUTPUTS
OUTPUTS A AND B
Two independent circuits,
short-circuit proof, with front panel SHV connector;
range 0 to 1000V; polarity positive or negative (both
outputs same polarity), selectable by front panel
Pos/Off/Neg switch. Output impedance
-
1.3 M
Ù
.
CURRENT MONITOR
Front panel jacks for
external monitoring of the current in each detector.
ELECTRICAL AND MECHANICAL
POWER REQUIREMENTS
+24 V, 205 mA; -24 V,
205 mA.
WEIGHT (Shipping)
7 lb, 4 oz (3.3 kg).
WEIGHT (Net)
4 lb (1.82 kg).
DIMENSIONS
NIM-standard double-width module
(2.70 by 8.714 in.) Per TID-20893 (Rev.)
RELATED EQUIPMENT
The 428 is compatible with ORTEC detectors and
ORTEC preamplifiers that have provisions for an
external detector bias voltage.
Summary of Contents for ORTEC 428
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