Specifications

C.9 SPSM—Shuttle Power Supply Master
WARNING
The input voltage to the SPSM board is full wave rectified line
voltage. Exercise care in troubleshooting this board to ensure
personnel safety.
The SPSM board (P/N 29-26734-00) converts full wave rectified line
voltage to 85V by way of four driver and four power stages. The 85V
is sent to the SPSR board (located in the power supply card cage).
The SPSM board contains two LEDs (CR10 and CR48). CR10 glows
when the 12V is at its operational level. If the internal crowbar circuit
operates, CR10 goes out. CR48 may flicker dimly if the -85 volt bus is
lightly loaded. This is normal.
The SPSM board (see Figure C-8) is located in the power supply card
cage.
Fuses: F1, F2, F3, F4, F5 (see Appendix A, LG31 System Fuses)
Controls: R102, R118 - Factory preset adjustments for 85V and current
limiting; do not adjust
Indicators: CR10 - Indicates 12V is present when illuminated
CR48 - Indicates 85V is present when illuminated – CR85 can
flicker dimly to indicate varying load conditions
Jumpers: None
C–14 LG31 PRINTED CIRCUIT BOARD SUMMARY