SU752544A1 - Timer - Google Patents

Description

The invention relates to automation elements.

Time relays are known on the basis of a magnetic amplifier with the inclusion of the time of driver elements in control circuits (feedback windings, control winds, displacements, etc.) 1.

The disadvantages of these relays are the short time delay, not exceeding tens of seconds, and the complexity of the magnetic amplifier.

Closest to the present invention is a time relay containing a time specifying a resistor, a capacitor, and a saturation inductor connected in series with the output element, and two diodes 2.

The disadvantages of such a relay are a short time delay, not exceeding tens of seconds, and the complexity of the circuit, which, apart from the time of the driver elements, includes two magnetic cores, three windings and many other elements.

The purpose of the invention is to increase the time delay and simplify the relay circuit.

The goal is achieved by the fact that the time of the driving capacitor is connected in series with one of the diodes, and the time of the driving resistor is connected in series with the other diode, moreover, these series circuits are connected to each other in parallel and in series with the throttle of the saturation, and the said diodes are connected oppositely to the parallel connection point circuits to the choke.

FIG. 1 shows a relay diagram; in fig. 2 - curves of magnetization reversal; in fig. 3 - graphs of currents and voltages.

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The time relay contains a choke 1 connected in series with the output element 2 and two diodes 3 and 4 connected in anti-parallel with respect to

15 drossel. The output element can be a display element, an actuator, an ac or dc electromagnetic relay (in the latter case, the coil of the relay is bypassed by a capacitor). 20 In series with one of the diodes, the time is set to the driving capacitor 5 connected to the discharge resistor 6. The time to the driving resistor 7 is connected in series with the other diode. The switch 8 connects the circuit to the AC power supply. The curve of the magnetization of the core of the throttle — the dependence of the magnetic induction B on the intensity of the magnetic field H — is close to rectangular and is shown (Fig. 2) by a solid line. Induction of a V drossel when exposed to full voltage supply is chosen slightly less than the induction of Bg saturation. The resistance of the output element 2, for example, the coils of the electromagnetic relay, is much less than the inductive resistance of the throttle, but more than its active resistance. The time delay starts from the moment the switch 8 is set to the lower position. From this point on, the AC voltage is applied to the relay circuit, and the conditionally positive current passing through diode 3 increases the induction of the throttle — magnetizes the choke, and the current of the orienting direction passing through diode 4 decreases the induction — degrades the choke. While one of the diodes is conducting, the other diode cannot turn on, since it is locked with the voltage of a conducting diode attached to it. The operation of the circuit is explained in FIG. 3, where the dash-dotted line shows the sinusoidal supply voltage, the flat solid line shows the droplet current, and the dotted line indicates the voltage across the capacitor. Since the inductive resistance of the throttle far exceeds all other resistances of the circuit, immediately after connecting the circuit to the power supply. The positive and negative half-waves of the current of the throttles passing respectively through diodes 3 and 4 are approximately equal, and the core of the throttles are completely reversal-induced - the induction changes from + W to -W. FIG. Figure 3 shows the switching on of the relay at time t o in the middle of the positive half-period of the supply voltage. The inductive current through diode 3 pulls in the diode's locking, and a part of the negative half-period continues. The end of the half-wave of the current and the blocking of diode 3, i.e., its conduction interval L, is determined by the equality of the vertically shaded areas - the differences of the supply voltage and voltage on the active resistance of the circuit, the latter on the scale coincides with the current of diode 3. of diode 3, the conduction interval Lg of diode 4 begins. The duration of its determination is the equality of horizontally shaded areas — the differences between the supply voltage on one side and the voltage on the capacitor 5 (see ) X and active resistance circuits (solid line) on the other side. Next, the conduction interval of diode 3 begins again, and so on. As can be seen from FIG. 3, the intervals L i and H g are equal at the beginning, and then the interval H i increases, and L a shortens. The pulses of the magnetizing current increase in magnitude and duration, and the demagnetizing decrease. After the beginning of the interval I i reaches the beginning, the positive half-period of the supply voltage, the magnetizing current stops growing, and the demagnetizing current pulses continue to decrease in duration and magnitude. Therefore, the capacitor is charged with increasingly shorter current pulses. Consequently, the charge current of a capacitor decreases not only in magnitude due to its charge, as in conventional RC circuits, but also in terms of the pulse duration, which leads to an increase in the delay time. As the capacitor 5 charges and the negative half-wave of the current becomes shorter and smaller, the core of the throttle begins to re-magnetize through partial cycles, two of which, corresponding to the negative inductions B i and B 2 of the adjacent periods, are shown in FIG. 2 dotted line. The difference in the magnetic energies of two adjacent cycles with inductions Bi and Ba corresponds to the energy accumulated in the capacitor over a period. In this case, the constant component of the current through the inductor begins to partially saturate the core. When the capacitor 5 is charged and the demagnetizing current pulses become very small, the core is completely saturated - the demagnetization induction approaches + BS - i.e. the whole period remains saturated. In this case, the inductance of the throttle decreases sharply, and since its active resistance is less than the resistance of the output element 2, the latter is triggered, marking the end of the time delay. To prepare the relay for the next cycle, switch 8 is moved to its upper position, discharging capacitor 5 through discharge resistor 6. The time delay is determined not only by the capacitance of capacitor 5, but also by the resistance of the resistor 7 and the inductance of the throttle 1. An increase in the resistance of the resistor 7 leads to an increase in the delay time due to a decrease in the magnetization current at a constant demagnetization current, and after saturation of the throttles due to a decrease in the voltage on the output element 2 to a value close to the threshold. An increase in the inductance of the throttle leads to an increase in the time delay of the flow, which decreases both the magnetizing current and the demagnetizing (condensate charge current {) a), and their difference decreases accordingly, causing the saturation of the throttles. The proposed relay in comparison with the known provides a significantly greater

a time delay much greater than that determined by the constant time C of the charge circuit of the capacitor.

Claims (2)

Invention Formula A time relay containing a time setting resistor, a capacitor and a saturation inductor connected in series with the output element, and two diodes, characterized in that, in order to increase the time delay and simplify the circuit, the time setting capacitor is connected in series with one of the diodes, and the time setting the resistor is connected in series with another diode, moreover, said successive circuits are interconnected in parallel and in series with the throttle of saturation, and the said diodes are connected opposite to the point of compound of parallel circuits to the choke. Sources of information taken into account in the examination 1. L. V. Chopin. Contactless electrical apparatus of automation. M., “Energie, 1976, p. 265. 2. USSR author's certificate number 420006, cl. H O H 47/18, 1972. I /. 6 FIG i FIG 2 FIG.