====== Secondary Power Supply ======
The secondary power supply (SPS) is a board that supplies regulated +5VDC and -8VDC. It also has the circuitry to  control the standard lamp (SL), mercury lamp (HG) temperature monitoring, stepper motor power and high voltage power (HV). \\
Note - Part of the SL, HG, and HV circuitry lives on the heatsink.\\
Note2 - The SPS board also includes the rate meter circuitry, however this is not used and usually shorted out to by pass it.\\

<hidden SPS board assembly>{{:boards:sps_board_assy.jpg?600|Secondary Power Supply Board Assembly}}</hidden>
<hidden SPS board schematic - Temperature circuit>{{:boards:sps_schematic_temp.jpg?600|Secondary Power Supply Schematic - Temperature monitoring circuit}}</hidden>
<hidden SPS board - HG, Stepper motor and voltage regulator>{{:boards:sps_schematic_hg_motor_reg.jpg?600|Secondary Power Supply Schematic - Mercury bulb, Stepper motor, and +5V/-8V Regulator circuit}}</hidden>
<hidden SPS board - HV and SL circuit>{{:boards:sps_schematic_hv_sl.jpg?600|Secondary Power Supply Schematic - High Voltage and Standard Lamp circuit}}</hidden>
<hidden SPS board potentiometer control>{{ :pictures:sps_pots.png?600 |Secondary Power Supply - Potentiometer Control}}</hidden>
<hidden SPS board V1 Top>{{ :boards:sps_board_v1_top.jpg?600 |SPS board V1 Top}}</hidden>
<hidden SPS board V1 Bottom>{{ :boards:sps_board_v1_bottom.jpg?600 |SPS board V1 Bottom}}</hidden>
<hidden SPS board V2 Top>{{ :boards:sps_board_v2_top.jpg?600 |SPS board V2 Top}}</hidden>
<hidden SPS board V2 Bottom>{{ :boards:sps_board_v2_bottom.jpg?600 |SPS board V1 Bottom}}</hidden>
Note: the V2 board is a version 2 board is in development board done by Environment and Climate Change Canada.

===== New & Old Temperature Circuit =====
To identify if the SPS board is using the new or old temperature circuit, you will need to locate the following  
^Resistor^Old Temperature Circuit^New Temperature Circuit^
|R601, R604, R605|11MΩ|825KΩ|
|R602, R606, R607|1.6MΩ|3MΩ|