| 摘要 |
The system is connected to an energy meter, and comprises a card reader handling cards provided with data concerning a predetermined quantity of energy, and a count-down unit which is also connected to the energy meter. The count-down unit receives from the card read-out a signal corresponding to the energy amount, and stores it in a memory. It also incorporates a circuit, and receives from the meter a signal corresponding to the momentary energy usage. This causes it to count down the stored energy quantity in the memory. - The count-down unit also comprises a control for a cut-off component which closes or breaks conductors moving the energy medium between the meter and the user point. When the memory counts down to zero, a control current is passed to a cut-off component to switch off the conductors. (Provisional Basic advised week 84/46)(0/2) |
