SU902255A1 - Timer - Google Patents

Description

one

The invention relates to automation, pulse technology and can be used to form at the output of a pulse of a predetermined duration after a certain predetermined time after the disappearance of the monitored voltage used in power automation automation devices, for example, when switching from a production plant to the main supply voltage which, with a controlled constant voltage and controlled voltage, ceases at the output the formation of a pulse.

A blocking time relay is known that contains a series-connected electromagnetic relay with latching, a dynistor, a capacitor, which is shunted by a C13 resistor.

The indicated relay is not reliable enough.

Known time relay containing the first capacitor connected through

a diode between the power supply terminals, a second capacitor connected through the aforementioned diode between the power supply terminal and the nullorgan input on two transistors connected according to the equivalent of a two-base diode, with an executive relay as a load, a resistive voltage divider of the power supply, a resistor connected in parallel 10 but to the first capacitor, the return winding. an executive relay is connected between the midpoint of the resistive voltage divider of the power supply and the input of the null organ, which is made to eq (1c Alente two-base diode 2.

The disadvantage of the known time relay is its low reliability due to the need to use

30 it has a two-winding electromechanical relay.

The purpose of the invention is to increase reliability.

To achieve this goal, a time switch containing two transistors, a voltage divider, the first output of which is connected to the first bus of a source of controlled voltage, the first capacitor, the first output of which is connected to the first bus of a source of controlled voltage, and the second output is connected through a diode with the second bus of the source of controlled voltage, the first diode connected between the first plate of the first capacitor and the base of the first transistor, the second diode connected between the output of the voltage divider and the first lining of the second capacitor, the second lining of which is connected to the first bus of a source of controlled voltage, and the collectors of transistors are interconnected and connected via a load element to the first bus of a source of controlled voltage, the emitter of the first transistor is connected to the base of the second transistor the first plate of the second capacitor, and the second output of the voltage divider is connected to the second output of the first capacitor.

The drawing shows a circuit diagram of the proposed time relay.

The device contains first 1 and second 2 buses of source 3 of source voltage, resistors and 5, diode 6, additional diode 7, time specifying capacitor 8, output transistor 9, input transistor 10, load 11, for example, a relay winding, additional capacitor 12, output 13 devices. The device also contains a capacitor 1, resistors 15 and 16, a diode 17.

The device works as follows.

After supplying the input voltage from source 3 through diode 17, necessary only if source 3 is alternating, capacitor 12 is charged, and capacitor 8 is charged through diode 6 and a divider on resistors and 5. Particularly, the charge time of the condenser 8 is selected taking into account the safety precautions of the equipment used and the start-up regulations of the technological line, and lies within 10 minutes. This prevents the equipment from restarting after the initial power interruption, when the technological parameters did not reach the pre-emergency value, and the mechanical characteristics of the mechanism did not go beyond the normal limits due to the inertia of the system, therefore the continuity of the technological process is ensured.

After the transients are complete, the time relay is ready for operation. In this case, the diode 7 is locked by reverse voltage and the transistors 9 and 10 are locked. The time relay almost does not lose electricity.

After the input monitored voltage disappears, capacitor 12 begins to discharge through a resistor.

After a predetermined time, the voltage on the capacitor 12 becomes less than the voltage on the capacitor 8, as a result of which the diode 7 and transistors 9 and 10 turn on, and an output pulse is formed on the load 11. The time duration of the output impulse is determined by the constant time of the discharge of the capacitor 8 by the value of the load resistance 11. If during this time the output voltage at the source 3 is restored, the pulse formation stops.

Claims (2)

1. USSR author's certificate N-, cl. H 01 H 7/18, 1969. 2. USSR author's certificate 53B2k3. CP N. 03 K 17/28. 1976 About Dprot © t41o1, --- "