CAEN
Electronic Instrumentation
A1539, AG539, A154X, AG54X Power Supply Boards
12
Boards with AMP interlock connectors
Short circuit pin 3 and 4 [the lower ones]. Leave contact open between pin 1 (+) and 2
(-) [upper ones]
Apply +5 V (3-4mA) differential signal between pin 1 (+) and 2 (-); pin 1 is the upper
one. Leave contact open between pin 3 and 4.
The INTERLOCK LED (red) is turned off as one of the actions above is performed.
When the channels are disabled the voltage outputs drop to zero at the maximum rate available; when
the output disable cause is removed (see above), the channels remain OFF until the User turns them ON
via software..
Grounding specifications
The Mod. A1539 - A154X channels share a common floating return (FAGND, see External connections),
available on the front panel multipin connector, insulated from the crate ground (AGND, see External
connections), which is available as front panel 2mm socket connector. This feature allows on-detector
grounding, thus avoiding loops which may increase noise level. FAGND and AGND may be coupled in
several ways, according to environment requirements. Examples refer to 32 channel version.
Safety Earth connection
The connection of shield and return to Earth is fundamental for User safety.
The connection must always be at the level of detector or power supply system.
Return and Shield connections even if not present or performed incorrectly, due to protection circuits
implemented on the A1539 - A154X are bound to Earth; in this case the voltage difference between
return and Earth (System), shield and Earth is limited to approximately 50V. Please note that this is a
status of emergency-protection, not a working one. The Connector Configurator allows to optimize the
connection of the shield, of the return and of AGND (Earth). The best configuration must be determined
by the user upon application, the optimal connection depends on many characteristics of the related
experiment.
