TEMPERATURE CONTROL UNIT

TM 11-6625-3081-23 1-10. DESCRIPTION OF ELECTRONIC STATION (cont) 1-10 b.1 TEMPERATURE CONTROL UNIT 1A1 The temperature control unit is an electronic assembly containing front and rear panel controls, indicators, electrical connectors, and an ac power cable. The front panel has a seven-segment temperature display, thumbwheel switches to set the source A and source temperatures, a joystick connector, and several switches and indicators. On the rear panel are connectors for the source A, B, and C inputs and a power input connector. Also on the rear panel are a GPIB interface bus connector and a GPIB address switch. The GPIB address switch is used to set the unique address of the temperature control unit to allow for the interchange of electronic data between the control unit and other electronic equipment. A ground lead connects to system ground. The temperature control unit is mounted to drawer slides so that it can be pulled out from the electronic station cabinet for maintenance purposes. The front panel will swing open for access to internal components. A master power switch on the rear panel is normally left in the ON position and the unit is powered up when EO bench power is applied. Characteristics Parameters Stability +/- 0.003°C short term +/- O.O1°C long term Settling Time <30 seconds Resolution Display O.01°C Setpoint O.O1°C, all sources Physical Data: Length 18.88 in Width 19.00 in Height 5.25 in Weight 30 lb Electrical Input: 115v 60 Hz c. CONTROL UNIT ASSEMBLY 1A1 (ALTERNATE) The control unit assembly 1A1 consists of a temperature controller (DBA Model 220) and drawer slides. The temperature controller is an electronic assembly containing front and rear panel controls, indicators, electrical connections and ac power cable. A ground lead is installed on the rear panel and connects to an electronic station ground terminal. On the front panel are thumbwheel temperature setting controls, temperature meter, switches, and LED indicators DS1 thru DS13. The front panel is hinge-mounted and will swing open after loosening two panel screws. CCAs, sensitive board mounted adjustable resistors, LED indicators, and other electronic devices are located inside the temperature controller. Four LED indicators, visible when-the front panel is open, are used to determine if the IEEE-488 bus is functioning. Each LED identity is placarded on the appropriate CCA. The following table identifies the LED placard and function. Change 9 1-13