Information concerning scaling factor and number of decimals is programmed on each channel board, and is connected to the system bus at the same time as the measured value. It is possible to program eight different factors with a 3-bit binary code, and the number of decimals can be 0, 1 or 2.
The display is normally dark and is only lit up when a push-button for manual measuring has been depressed, the displayed value will follow the fluctuations of the signal. When the push-button is released, the value will remain unchanged for about five seconds.
Honieiask: Ex. 40, 42.
Key
6 — cdfgiko; 7 — acfghlmpqrtuvxya' e'; 24 — A automatic control, В application of control; 35— lb, 2c, 3a.
Power Plant Control System. Design
1. The system comprises the following units: basic unit, synchronizing and load sharing unit, additional monitoring unit, central units, relay unit, transformer unit, relay unit for controlled loads.
2. The electronic units consist of identical boxes furnished with different electronic boards and fronts. The boxes are made of sheet steel and provided with ventilation holes. A printed circuit board, the “mother board’’, constitutes the internal wiring and is connected to the terminal board by a flexible ribbon cable. Together, these two boards form the rear of the box. Some programming is performed by jumpers on the mother board.
The terminal board has two rows each with 33 terminals foe, external connections.
3. The electronic boards are inserted from the front of the box. All indi- >4 eating lamps and push-buttons are mounted on the boards and the front plate contains corresponding lamp glasses with engraved text.
4. The maximum number of different electronic boards is seven and every ' board has a distinct limitation of functions. This implies that any faults
can easily be corrected and few spare parts are required.
5. The relay and transformer units are built up in 19 inch standard racks and function as interface and output stages between the electronics and the peripheral equipment.
6. The basic units, the additional monitoring units and the central unit shall be applied from a 24 V battery, while the synchronizing and load sharing units are to be supplied from the generators via the transformer units.
7. The system can be adapted to different types of engines, generators and other relevant equipment.