SU729521A1 - Logic threshold device - Google Patents

Description

(54) LOGICAL THRESHOLD DEVICE The invention relates to measuring technique and can be used in automatic control systems. The known logical threshold devices are based on comparing the set value corresponding to the control threshold with the current value of the source information signal 1 and 12. However, to obtain information is more, less and the norm requires a large amount of logic elements. The closest to the invention is a logical threshold device containing counter decades, digital pulse selectors with bit switches and indicators of the presence and absence of pulses 3. The threshold is set by connecting digit digital selector switches to the corresponding outputs of the decimal code, and by the presence of a pulse at the output of the selector, the ratios between the set control threshold and the measured value are determined. At the same time, the indicators of the absence or presence of pulses are triggered, which corresponds to a command less or more. However, in this device there is no possibility of receiving a command rate, in addition, connecting digital selectors directly to the meter reduces the reliability of the latter. To implement such a technical solution, a large amount of logical elements of the NAND, NOR and triggers type is required. The aim of the invention is to simplify the threshold device. This is achieved by introducing a polling generator connected to the anode of the indicator lamp into a logical threshold device containing a decade counter and associated gas discharge indicator lamp and switches, the cathodes of which are combined with each other in the order of counting from a series-connected capacitor and a corresponding switch, the switch in the cathode circuit, corresponding to the control threshold digit, is connected to the bus norm, in addition, the cathode of the indicator lamp, corresponding to The second digit is connected to the bus less, and the cathode of the indicator lamp, corresponding to the maximum number, is connected to the bus more.

The drawing shows a functional block diagram of a logical threshold device.

The device contains a polling generator 1 connected via a discharge capacitor 2 to a gas discharge indicator lamp 3, capacitors 4 and resistors 5 in the circuit of cathodes of the indicator lamp 3, switches 6 connected in series with capacitors 4, unit 7 for setting the control threshold connected to switches 6, and a decade counter 8, connected to the cathodes of the indicator lamp 3. The cathodes of the indicator 3, corresponding to the minimum and maximum monitored figures, are less and more connected, and the bus is normal through the corresponding ix switches 6 is connected to the cathode of a controlled numbers.

The contents of the decade counter 8 are displayed on a gas discharge indicator lamp 3

The controlled number is set using the threshold setting unit 7 by the switches 6, for which the corresponding switch 6 breaks the connection of the corresponding cathode of the indicator lamp 3 with the others, and one pair of contacts the switch 6 is connected to the bus on which the norm command is generated. The cathodes of the indicator lamp 3 are connected through capacitors 4 to each other in the order of counting, with the exception of the cathode corresponding to the controlled figure.

In the example of construction of the scheme shown in the drawing, the control of the number 3 is shown.

In this case, if any digit less than 3 is switched on, then through the chain consisting of switches 6 and capacitors 4 closed in the counting order, the pulse from the poll generator 1 goes through the ionized gap to the cathode

the minimum number (in this case, O) from which the command is less.

Similarly, a command is generated more from the cathode corresponding to the maximum digit (in this case, 9), if you turn on: a digit greater than 3.

With the help of switches 6 you can adjust the limit of controlled numbers.

Thus, this threshold device, without typing complex logic circuits, allows control of any measurable parameter represented in decimal code.

Claims (3)

Invention Formula A logical threshold device containing a decade counter, a gas-discharge indicator lamp and switches, characterized in that, in order to simplify the device, it contains a polling generator connected to the indicator lamp anode, the cathodes of which are interconnected in order of counting from a series-connected capacitor. and the corresponding switch, and the switch in the cathode circuit corresponding to the control threshold digit is connected to the bus norm, while the cathode of the indicator lamp corresponding to the minimum digit is connected to the bus less, and the indicator cathode corresponding to the maximum digit is connected to the bus more. Sources of information, take into account in the examination, 1. USSR author's certificate N 328490, cl. G 06 M 3/04, 12.11.1970. 2. Brufman S. S. Nlfrovye elements of comparison. M., Energie, 1967. 3. Authors certificate of the USSR N 233091, cl. G 01 R 23/10, 04/06/1970.