| 摘要 |
An input voltage (Ue) supplies via a diode (7) and one series resistor (17, 9) each both the load (3) and a Ni-Cd cell (10) for maintaining operation in the event of power failure. A capacitor (36) which is charged in the pulse pauses supplies the pulse energy. The Ni-Cd cell (10) stabilises the supply voltage for the circuit (1). One switching device (24, 20) each, which is dependent on the voltage potential at one terminal (11) of the Ni-Cd cell (10), is present in in each case one supply lead (18, 19) to the load (3) or to a supply terminal (13) on the circuit (1). These serve the purpose of maintaining operation of the clock timer in the event of failure of the Ni-Cd cell (10), and are permanently open when the Ni-Cd cell (10) is short circuited, while they are otherwise conductive either permanently or only for the duration of the pulses. A stabilising diode (15) and a puffer capacitor (16) are connected in parallel to the supply terminals (13, 14). Transistors (20, 24) or a diode serve as the switching device. The transistors in the supply lead to the load (3) can be controlled by the pulse of the circuit (1). <IMAGE> |
