POWER SYSTEM SCHEMATIC: Panels are terrestrial teflon coated silicon cells. There are 4 panels per face connected in pairs to an "A" system and "B" system for redundancy. Each string produces about 18 volts open circuit and will be connected to our 12 cell, 14.4 volt NICAD battery for self regulation. Charge will taper to under 50 ma if the batteries are fully charged. Dual battery systems provide dual power busses and the Transmitters are directly connected to the busses. The following schematic shows one of the dual redundant systems: *--->|-----------------------------------* | *--->|---------------------------* | | *--->|-------------------* | | | *--->|-----------* | | | | *--->|---*-----*-------------*----> Bus |-----| |-----| |-----| |-----| |-----| | ___|___ |SOLAR| |SOLAR| |SOLAR| |SOLAR| |SOLAR| = | 3w | |PANEL| |PANEL| |PANEL| |PANEL| |PANEL| ---Bat 2 |XMTR | | top | | 2 | | 3 | | 4 | | 5 | = 12 cells | | |-----| |-----| |-----| |-----| |-----| --- |-----| | | | | | | | *I1 *I2 *I3 | | | | \ \ \ | | | | / 1 / 1 / 1 | | | | \ \ \ | | | | | | | | | | | *-------*-------*-------*-------*--------------*------------*----> GND Solar array currents I1-I3 are measured as voltage drops across .1 ohm resistors and converted to 0-5 volt telemetry voltage range with a transistor amplifier. There are fuses to isolate the transmitters and/or batteries in case of failure and all systems are dual redundant. Temperature and voltage telemetry are taken using voltage dividers: * Vbatt (0-10v) *-------------------* 5v | | *--/\/\/---*-------------|-------------------> TVbat (0-5v) 10k | | *--/\/\/--* *--/\/\/--*---------> TVtemp (0-5v) 10k | R1 | --- THRM *--/\/\/--* /// R2 | --- /// TEMPERATURE: There are temp sensors on every face (6), in the two TNC systems (2) and in the batteries (2) and one at the center of the spacecraft structure.