| 摘要 |
The subject of this invention involves a system of discharging condenser, particularly in time-based circuits designed on charging the condenser through resistance principle.Time segments RC are widely known and are often applied to obtain time delays, particularly in time specified-time relays, automatic elevators etc.Basic fault of the majority of those devices is that following a temporary supply voltage loss during the countdown of specified time; the timing sequence condenser is left partly charged when voltage is restored later. This causes that time countdown is not based on zero value, but on some undetermined voltage level. In many instances this fault makes use of such relays impossible, or might cause a breakdown of the controllable equipment.There are electronic systems of specified time relays in place, which eliminate this fault, albeit in a relatively complicated manner. An example is the integrated CMOS type circuit relay.The above-mentioned faults are eliminated by the condenser discharge circuit, in accordance with the invention. It is particularly useful in time relay controlled circuits by making possible to countdown from zero, even subsequently to temporary loss of supply voltage. It allows constructing a very simple time relay with good technical parameters.In accordance with this invention, the condenser discharge circuit is built from a diode and resistant voltage divider. The anode of the diode is connected to the common resistor and condenser of timing circuit, while its cathode is connected to the common point of two voltage divider resistors, with one of them connected to resistor, while the second to timing circuit condenser RC. In some cases the first resistor of voltage divider can be disregarded.The subject of this invention is depicted in the example of as executed drawing, with fig. 1 depicting the condenser discharge circuit, while fig. 2 represents another version.
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