5
compatible with the principles of DOE Report TID-
20893 (Rev), January 1968, "Standard Nuclear
Instrument Modules." This report, the work of a
committee of equipment users from AEC-related
institutions, establishes standards for a modular
instrument system whic h allow electrical and
mechanical interchangeability of units made in
c onformance with the standards. The standards
prescribe the necessary mechanical dimensions and
c onnec t or
t y pes
to ensure
mec hanic al
interchangeability. They also specify standard power
s upply voltages and pin assignments in the
connector so that electrical interchangeability is
assured, at least with respect to the main connector
joining the module to the bin.
The 4002P Port able Power Supply is a complete
assembly. It furnishes the power that is distributed
to the module connectors through the assigned pins.
A power ground return, a high-quality signal ground,
and +12 V,
!
12 V, +24 V, and
!
24 V are included in
the distribution circuits. The power supply accepts
input power from 100, 120. 220, or 240 V ac mains,
47–63 Hz.
4. OPERATING INSTRUCTIONS
4.1. CONTROL PANEL FUNCTIONS
An On-Off switch interrupts both sides of the input
power line. A Power pilot lamp indicates that ac
input power is being supplied to the power
transformer primary. Either a blown fuse or a
temperature cutout will extinguish this lamp.
A Temp (temperature) warning pilot lamp is
illuminated when the power supply temperat ure
rises to within approximately 13
E
C of the maximum
s afe operating temperature. When the maximum
safe temperature is reached, an internal cutout in
the power supply removes power and neither lamp
will be illuminated.
Test jacks on the panel allow convenient checking
of the power supply voltages from the front panel
without disassembly of the unit.
4.2. POWER SUPPLY LIMITATIONS
The power supply capability is stated on the front
control panel. The user should verify that the power
supply capability is not exceeded when module
connections are made.
4.3. CONNECTION AND DISCONNECTION
No damage will result to the power supply from the
connection or disconnection of modules while the
power is on. However, since the sequence of power
application to a module is indeterminate when
connected with the power on, it is prudent to turn the
power supply off when connecting, dis-connecting,
or changing modules.
5. CIRCUIT DESCRIPTION
The power supply produces four dc output voltages.
A power transformer transforms the input ac line
voltage into four separate low-voltage sources. The
sources or windings are full-wave-rec t ified,
capacitor-filtered, and regulated by electronic series
regulator circuits. The regulator circuits provide
short-circuit, current-limiting, and reverse-current
protection.
Each of the four series regulator circuits are
identical in operation; they are physically different
only in component values for each supply. The
regulator can operate in two modes: First and
normal is the voltage regulation mode; second is the
current-foldback or current-limiting protection mode.
The regulator will operate in the volt age regulation
mode at any current output up to and including the
full rated output of a particular supply. When current
output beyond 150% of the rated output is required,
which includes a direct short across t he output
