BLS Power Supply


David L. Huffman

The BLS Power Supply provides power for the BLS Crate electronics. The Run I supplies have been reworked to provide the new electronics with its power requirements. Each BLS supply is a dual unit that powers two electronics crates. The crates are located to the right and left of the supply in the three-rack system. The supply has one common raw DC source used by each half of the unit. Each half is controlled and operated separately. There are six different voltage outputs supplied to the crate. These are the ratings of each output for each half of the power supply.

Ratings/Each Side
+7V @ 25A
-3V @ 20A
+13V @ 20A
-12V @ 5A
+5V @ 20A
-5.2V @ 10A

Each output is protected with over current, over voltage and over temperature sensing. In addition each output regulator has a breaker or fuse on its connection point to the raw supply. This prevents any currents from exceeding the rating of the wiring. The AC input (208 3-Phase) has a magnetic breaker rated at 10 Amps. The input AC comes from an AC Distribution box just like the ones used for the Preamp Power Supplies. The only difference is the breaker size, which is 10 Amps.

The supply receives an external interlock signal from the Rack Monitor Interface chassis. The RMI processes information from adjacent racks to provide interlocking for water flow, smoke detection and water leaks via drip detectors. Any one of these faults will signal the supply and disable the high power circuitry, removing the 208V 3-Phase current to the high power raw supply. Control power is always on when the front panel breaker is on.

Computer interfacing is provided via Rack Monitor chassis (1553) and requires two Analog ribbon cables and two digital ribbon cables. A Selector module is used to set the power supply position in the rack. The module tells the supply how to output digital information to the Rack Monitor. This is necessary because of the large number of digital bits readback through the Rack Monitor chassis.

The computer interfacing descriptions are given here.

Recent changes:

The original Run I supplies were changed in the following manner.