SU970122A1 - Two-position level relay - Google Patents

Description

the first key, and the output of the second key - with a common electrode. The drawing shows a diagram of a two-stage level switch.

The circuit contains a pulse generator 1, a one-shot 2, which is connected to the output of the pulse generator 1 and an output to the inputs of keys 3 and 4, the outputs of which are connected to common points of voltage dividers, and to the inputs of two I-NB 5 and 6

The other inputs of the two elements, AND-HE 5 and B, are connected directly to the midpoint of the voltage divider (CL of the electrical contact rod 7 of the lower level and, through the AND-HE element 8, to the midpoint of the voltage divider for the electrical contact rod of the upper level. Electrocontact rods 7 and 9 form voltage dividers with resistors 10 and 11. The outputs of the AND-NE elements 5 and b are connected to the corresponding inputs of the trigger 12, which through the switch on the driver 13 swaps to the actuator 14. The common electrode 15 is connected to the output of the key cha 3.

The two-position level switch operates as follows.

The pulses of the generator 1 are fed to the input of the one-shot 2, forming short pulses.

The pulses from the one-shot output, 2 control the operation of the keys 3 and 4, and also control the passage of signals from the middle points of the voltage dividers to the inputs of the RS flip-flop 12.

When the level of the monitored medium is below the lower level electrode 7 and at the output of the one-oscillator 2 there is a polling pulse, which leads to unlocking the keys 3 and 4 and supplying voltage to the voltage dividers, the first inputs of the AND-HE elements 5 and b are respectively logic signals zero and logical unit. At the other inputs of the AND-NE elements 5 and 6 there is a polling pulse, while the S- and R-inputs of the RS-flip-flop 12 present, respectively, the signals of a logical zero and a logical one, which causes the RS-flip-flop 12 to be set to one and to enable, through a switch on a simistor 13, an actuating element 14, ocjmie which fills the capacity in which the level is controlled,

In the absence of a polling pulse at the output of the one-shot 2, the RS-flip-flop 12 does not change its single state, since the R- and S-inputs of the signals are equal to a logical one (the inputs of the H-HE 5 and b elements contain a logical zero signal).

When the level of the controlled medium rises to the electrode 7 and in the presence of the interrogation signal at the output of the one-vibrator 2 at the inputs of the element NID, the signals are equal: logical

zero (resistance 11 is such that when the electrode 7 is immersed in a controlled environment and in the presence of a supply voltage on the voltage divider at the midpoint of the divider

0, the voltage of the signal is equal to a logical zero) and the logical one. The signals at the inputs of the NAND element 5 have not changed and are equal to the input signals of the element NAND 6. Therefore, the state of the RS flip-flop 12 does not change, Does not change its state and xs 1 the switch on the triac 13 and the actuator 14.

If there is no polling signal on

Q, the output of the one-shot 2, and consequently, at the inputs of the elements AND-NOT 5 and b at their outputs, the signals are equal to a logical one and do not depend on the level of the controlled medium.

The signals of the logical unit at the R- and S-inputs of the trigger 12 do not change the initial state of the RS-flip-flop 12, and therefore, the switch on the triac 13 and the actuator 14.

When the level of the controlled medium reaches the electrode 9 in the presence of a polling signal at the output of the one-shot 2 at the inputs of the element

AND-NOT 5 signals are equal to the logical unit (the nominal value of resistors 11 and 10 is the same, and at the output of the element and -ONE 8 when the input signal is logical zero, the signal is equal to logical one), and at the inputs of the element AND-NOT b the input signals are constant and equal to logical one and logical zero, therefore, at the S and I inputs of trigger 12, the signals are respectively equal to logical one and logical zero, and trigger 12 changes its state from one to zero, which leads to switching off of the actuating element 14 through the switch on the triac 13 and termination filling the tank in which the level is controlled.

Claims (2)

When the level of the monitored medium, decreasing, does not reach the electrode 9, at the first inputs of the AND-NE 5 and .6 elements, in the presence of the interrogation signal at the output of the one-vibrator 2, the signals are equal to logical zero, respectively. At the R and W inputs of the trigger 12, the signals are logical unit, which does not lead to a change in the zero state of the RS flip-flop 12. The zero state of the RS flip-flop 12 corresponds to the disabled state of the actuating element 14. In the future, the operation of the two-position level switch repeats. In the absence of polling signals at the output of the one-shot 2, the keys 3 and 4 are closed, and the current through the electrode sensors does not flow, and if there is a polling signal at the input of the transistor switches 3 and 4, the latter are unlocked, and the power supply voltage is applied to the voltage dividers leads to the flow of current through the electrode sensors subject to contact with a controlled medium. Assuming that the frequency of the polling pulses at the output of the one-shot 2 is 10 Hz, and their duration is 510 s, the duty cycle of the polling pulses is 200,000. Claims of the invention Two-level level switch containing a three-electrode sensor with one common electrode and upper and lower levels electrodes, a pulse generator, A switch connected to an actuator, characterized in that, in order to reduce power consumption and increase operational reliability, it is equipped with a single vibrator connected to the generator output, with two switches connected by their inputs between themselves and with the output of a single vibrator, an RS flip-flop, the output of which is connected to a switch, and three AND-NOT elements, two of which are connected to the corresponding input of the RS flip-flop, and the first directly to the bottom electrode level, and the second through the third element AND-NOT to the electrode of the upper level, while the electrodes of the upper and lower levels are connected through an additional resistance to the output of the first key, and the output of the second key to the common electrode. Sources of information taken into account during the examination 1. USSR author's certificate №614333, cl. G 01 F 23/24, .1976. 2. USSR author's certificate №574624, cl. G 01 F 23/24, 1975 (prototype). fО About Enunt go Have - -/five