SU1335923A1 - Threshold device - Google Patents

Abstract

The invention relates to the field of electronic automation devices and is intended for comparing analog signals, creating voltage protection circuits, current overloads and creating key voltage regulators. The device contains a threshold unit, four constant resistors and one alternating, three diodes and a transistor. The essence of the invention is to increase the hysteresis between the magnitudes of the monitored signal when triggered and released the threshold block, made on a chip of type 142EP1 .. 2 Il. (L

Description

The invention relates to electron-HfiiM automation devices, namely, electrical elements comparing analog signals, and can be used to create various protection schemes for reducing (decreasing) voltage, current overloads and for creating key voltage regulators.

The purpose of the invention is to increase the noise immunity of the threshold device by increasing the hysteresis.

Fig. 1 shows a functional diagram of the threshold device j in Fig. 2, a schematic diagram of the execution of the threshold unit.

The threshold device contains a threshold unit 1,. Transistor 2. the first output 3 of the power supply of the threshold unit 1, the limiting resistor 4, the third resistor 5, the input 6 of the threshold unit, the variable resistor 7, the second output

8 power units .threshold unit 1, first

9 and the second 10 resistors, the first diode 11, the output 12 of the threshold unit, the second 13 and the third 14 diodes, the first 15 and the second 16 of the power bus.

The threshold unit 1 contains the first 17 and second 18 resistors, the transistor 19, the third resistor 20, the first to fourteen11 pins 21-34 of the control circuit of the key voltage regulator and the chip 35 of type EP1 142,

The device works as follows.

Suppose that the voltage of the power source rises monotonously from the zero initial value. In this case, the negative unit 1 is in such a state that its output 12 is closed to the second negative bus 16 of the power supply and the second resistor 10 shunts the chain of the first 9 and third 5 resistors, while the transistor 2

off, since its unlocking potential is shunted by a circuit: the second diode is 13 isolates, output 12 is the threshold of block 1,

In this state, the device remains until the voltage drop across the third resistor 5 reaches the response level of the threshold unit 1.

The operation of the threshold unit 1 leads to the disconnection of the communication circuit of the second resistor 10 with the second negative

five

power bus 16 and the appearance at input 6 of threshold unit 1 of a positive voltage drop of the monitored signal. The transistor 2 when triggered by the threshold unit 1 is connected in the circuit: limiting resistor 4, the third diode 14,

Let the power supply voltage monotonously decrease from the maximum value. At the time when the voltage drop across the third resistor 5 reaches the release level of threshold unit 1, the latter switches to the initial initial state and the output circuit of the 12th threshold unit 1 with the second bus 16 the power is restored again. A negative voltage drop of the monitored signal occurs at the input 6 of the threshold unit 1, and the transistor 2 turns off.

These voltage drops increase the width of the hysteresis loop on the switching characteristics of the device, and their value can be adjusted over a wide range by varying the resistance of the second resistor 10. This provides the proposed threshold device compared to the known stable operation at high levels of interference levels of interference (when

5 stable operation of the device, the width of the hysteresis loop must be adjusted) 5 expansion of the area when 0

five

for example, in relay key

40

voltage regulators, where the adjustment of the operation mode (adjustment frequency, power consumption, etc.) for given parameters of the reactive elements of the power circuit is adjusted by adjusting the hysteresis 45 between the values of the monitored signal when the control device is switched.

Claims (1)

Invention Formula A threshold device containing the first and second power lines, a threshold unit, a first resistor, a limiting resistor and a transistor, the first power line is connected to the limiting resistor, and the second power line is connected to the first power terminal of the threshold unit, characterized in that noise immunity due to an increase in hysteresis, it additionally contains second and third resistors, a variable resistor and three diodes, the first power supply bus is one of the outputs of the device and is connected to the second output of the power supply. and the threshold unit directly and through a series-connected variable resistor and the first resistor are connected to the input of the threshold unit, which through the third resistor is connected to the second power bus and the emitter of the trans A transistor whose collector is the second output of the device, and the base of the transistor through the third diode in the non-conducting direction is connected to the second output of the limiting resistor and connected to the output of the threshold unit through the second diode in the conductive direction The second direction and the second resistor are connected to the common point of the first resistor and the variable resistor. figure 1 Compiled by B. Kirsanov Editor S. Pekar Tehred V. Kadar Proofreader L. Bezkid Order 4045/40 Circulation 863 Subscription BNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 fig 2.