WHAT

Design of power supply crate: 
1. one is the prototype version for Ben Mazin’s group at UCSB 
2. The next two are the final versions for MUSIC instrument

WHY

To supply the required voltages and currents to the readout electronics crate, a power supply crate is needed.

HOW

**** THE FOLLOWING DISCUSSION PERTAINS TO MUSIC INSTRUMENT’S POWER SUPPLY ONLY ****

Here is a block diagram of the general internal wiring for the MUSIC power supply crate. Note that an emphasis has been placed on the two separate ground potentials available. For the sake of safety, the chassis ground is established as the metal skeleton of the crate, to include the chassis on the Acopian unregulated power supply modules, switching power module, and the linear power supply modules, and the chassis designed into the DC/DC regulator PCB.
 PS_box_wiring_MUSIC.pdf

The schematic for the DC/DC regulator board is in the following: Regulator_1_MUSIC.pdf 
The top and bottom of the PCB are shown in the following:
regulator_top.pdf 
regulator_bottom.pdf 
The bill of materials for assembling one board: BillOfMaterials_PS_MUSIC.pdf

Parts List for the Power Supply Crate: Power_Supply_Crate_Parts_List.pdf 
Notice the two values of wirewound resistors, 8.2 ohms and 20 ohms, respectfully. These are used in series with the fans to reduce the +15VDC switching power supply voltage to between +12-13VDC for proper fan operation. The 8.2-ohm resistors are used with the MultiComp MC21685 325mA fans, while the 20-ohm resistors are used with the MultiComp MC32919 130mA fans.

The off-the-shelf rack cabinet is made by Hammond Manufacturing. It is the model RCHS1901017, a 6U high, 19” wide, heavy duty table-top rack cabinet: RCHS1901017.pdf

Complete AutoCad drawing file for the Power Supply Crate: PS_Box_1.dwg 
CAD views of the complete Power Supply Crate: 
Front: PS_Box_front.pdf 
Rear: PS_Box_rear.pdf

Listing of the machined parts for the Power Supply Crate; these are the AutoCad 3-D drawing, the AutoCad dimensional drawing, and the PDF dimensional drawing:


1. MUSIC_bottom_support_plate_3D.dwg 
MUSIC_bottom_support_plate_dim.dwg 
MUSIC_bottom_support_plate_dim.pdf
2. MUSIC_bottom_support_rail_3D.dwg 
MUSIC_bottom_support_rail_dim.dwg 
MUSIC_bottom_support_rail_dim.pdf
3. MUSIC_mounting_plate_linearPS_3D.dwg 
MUSIC_mounting_plate_linearPS_dim.dwg 
MUSIC_mounting_plate_linearPS_dim.pdf
4. MUSIC_mounting_plate_switchingPS_3D.dwg 
MUSIC_mounting_plate_switchingPS_dim.dwg 
MUSIC_mounting_plate_switchingPS_dim.pdf
5. MUSIC_mounting_plate_unregPS_3D.dwg 
MUSIC_mounting_plate_unregPS_dim.dwg 
MUSIC_mounting_plate_unregPS_dim.pdf
6. MUSIC_top_support_plate_3D.dwg 
MUSIC_top_support_plate_dim.dwg 
MUSIC_top_support_plate_dim.pdf
7. MUSIC_top_support_rail_3D.dwg 
MUSIC_top_support_rail_dim.dwg 
MUSIC_top_support_rail_dim.pdf

The two front panels are blank aluminum 0.125” thick Hammond Manufacturing PBPA19005BK2: PBPA19005.pdf

One is machined for mounting cooling fans and power connectors, with silkscreen information: 
MUSIC_Front_Fan_panel_3D.dwg 
MUSIC_Front_Fan_panel_dim.dwg 
MUSIC_Front_Fan_panel_dim.pdf 
MUSIC_Front_Fan_panel_silkscreen.pdf

One is machined for status LEDs and lower intake cooling holes: 
MUSIC_Front_LED_panel_3D.dwg 
MUSIC_Front_LED_panel_dim.dwg 
MUSIC_Front_LED_panel_dim.pdf 
MUSIC_Front_LED_panel_silkscreen.pdf

The upper rear panel consists of one steel 0.060” thick perforated panel for venting heat out the top rear of the power supply crate, Hammond Manufacturing PPFS19005BK2: PPFS19005.pdf

The lower rear panel consists of one blank steel 0.060” thick Hammond Manufacturing PBFS19005BK2: PBFS19005.pdf 
This panel is machined with a cutout for the power entry module (110 AC + fuse + filtering) and two rows of venting holes along the top edge: 
MUSIC_Power_Entry_Panel_3D.dwg 
MUSIC_Power_Entry_Panel_dim.dwg 
MUSIC_Power_Entry_Panel_dim.pdf 

The power entry module specification sheet is: typ_KMF.pdf
For adjusting the current limit on the Acopian +15VDC switching power supply: Instructions_current_limit_adj.pdf