Time Electronics 1077 Milliamp Transducer Simulator - Manual (Page 14)

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1077 Technical Manual P a g e | 14
5.
C ircuit Des cription
5.1. Power Supply
The batteries and power supply circuitry is located on the bracket which is mounted below
the battery level indicator. Eight AA size rechargeable batteries provide an output of 9.6
volts D.C. to power a switched mode regulator which generates all the regulated supplies for
the 1077 and the adjustable output voltage.
The rechargeable battery is protected by a miniature fuse mounted on the board. The fuse
is rated at F1A and has dimensions of 20mm length by 5mm diameter.
5.2. Mains Recharger
The mains recharger is a separate unit and enables the 1077 batteries to be fully charged in
12-14 hours. An overnight charge is usually adequate. The mains input is 200-240 volts
50/60 Hz standard. 100-120 volts, 50/60 Hz are available but should be specified on
ordering. The plug and socket are shaped to ensure that they cannot be connected in the
wrong polarity.
5.3. Circuit Module and Range Switch
The 1077 active circuitry and range switch are located on a printed circuit board which is
mounted on the front panel. Connection to the P.C.B. is via a 9 pin connector. The active
circuitry is encapsulated and contains the precision reference circuitry and output stage.
Four calibration trimmers are mounted on the P.C.B. (ref. section 6.4).
A replacement procedure should be adopted in the case of failure.