SU1679046A1 - Time relay - Google Patents

Abstract

The invention relates to a pulse technique and can be used in automatic control and monitoring systems. The purpose of the invention is to expand the range of dependence of the duration of the output time interval on the duration of the input. The relay contains an RC circuit 1 on a resistor 2 and a capacitor 3, a discriminator 4 levels on transistors 5, b, a voltage divider on resistors 7, 8 and an input terminal 9. Introduction to the relay of an additional capacitor 10 and the execution of the equivalent circuit of a two-base diode transistor equivalent simplifies the relay, ensures its operation with a single input signal and increases noise immunity, and also provides an additional range of time dependencies on the duration of the trigger signal, which expands the range of dependence. 1 silt

Description

The invention relates to a pulse technique and can be used in automatic control and monitoring systems.

The purpose of the invention is to expand the range of dependence of the time delay on the duration of the trigger signal.

The drawing shows a circuit diagram of a time relay.

The time relay contains an RC circuit 1 on a resistor 2 and a capacitor 3, a level 4 discriminator on transistors 5 and 6, a resistor 7 and an additional resistor 8, an input terminal (control bus) 9 and a capacitor 10.

Resistors 2 and 7 and capacitors 3 and 10 form a resistive-capacitive bridge. The input terminal 9 is connected to the output of the first shoulder of the bridge on the resistor 2 and the capacitor 3. An additional resistor 8 is connected in series to the capacitive branch of the second shoulder of the bridge. The level discriminator comparison scheme is based on a two-transistor analog of a single-junction transistor (transistors 5 and 6), and the emitter-base transistor 5 junction is included in one diagonal of the bridge, the other diagonal of which is connected to the power buses.

The relay operates as follows.

When a time relay is connected to a power source and in the absence of an input signal, capacitors 3 and 10 begin to charge. When comparing the voltages across the capacitors, the transistors 5 and 6 of the analog of the single-junction transistor open, the capacitor 10 discharges through the open transistors 5 and 6 and the resistor 8. Thus, the time relay goes into a stable state and is ready to work with a periodic input signal, with the transistors 5 and 6 being held in the open state, the current flowing through the resistor 7, which ensures the discharged state of the capacitor 10.

When connected to the input terminal 9 of a source with a varying input frequency with a constant duty cycle during the pause (pulse) of the input frequency, which corresponds to the duration of the start signal, terminal 9 is connected to the negative of the power source. This ensures that, from the moment of a pause, the discharge of the capacitor 3, turning off the transistors 5 and 6 and the beginning of the charge of the capacitor 10. During the pulse (pause) of the input frequency, terminal 9 is disconnected from the minus of the power source, which ensures the beginning of the charge of the capacitor from the moment of the appearance of the pulse of the input frequency 3. In the interval of the pulse width of the input frequency, the voltages on the capacitors 3 and 10 are compared, the transistors 5 and 6 are opened, and the output pulse is formed by the discharge current of the capacitor 10. Time, source kshee from the end of time (trigger signal) until the response timer, determines the exposure time relay, and hence the phase of the leading edge of the output pulse.

Changing the input frequency leads to a change in the pause duration of the input frequency (start signal), which in turn leads to a change in the threshold of the relay provided by the resistive-capacitive reference voltage divider on resistors 7 and 8 and capacitor 10. This leads to a change in the relay time delay, and therefore to a change in the phase of the output pulse.

With a zero value of the resistance value of the resistor 8, a constant time constant of the resistive-capacitive divider 1 of the input voltage of the gamma of dependences of the time delay on the duration of the start signal, obtained when the resistance value of the resistor 7 is changed, it is similar to the gamma of dependencies of the known relay, and when the resistance value of the resistor 8 is not equal zero, at the output of the resistive-capacitive reference voltage divider (R7, СУ) after the closure of transistors 5 and 6, a voltage jump appears, the value of which is determined the ratio of the resistances of the resistors 7 and 8, which provides a time-varying form of the dependence of the time delay on the duration of the start signal when the frequency of the input signal varies, different from any form of the gamma of dependencies of a known relay. By changing the values of the resistances of resistors 7 and 8, you can change the magnitude of the voltage jump and get an additional gamut of time delay dependencies on the duration of the start signal, which extends the range of dependencies.

Running the comparison circuit on a two-transistor analogue of a single-junction transistor and connecting the input terminal directly to the output of the resistive-capacitive input voltage divider simplifies the time relay, ensures its operation with one input signal and increases noise immunity, since short-term interference of the starting signal at the input terminal 9 is suppressed by capacitor 3. In addition , capacitive energy is used to form the output pulse, which increases the efficiency of the time relay.

Claims (1)

Claim A time relay containing a resistive-capacitive bridge, in one diagonal of which a comparison circuit is included, another diagonal of the bridge is connected to power buses, a control bus connected to the output of the first shoulder of the bridge, which differs in that. that, in order to expand the range of the dependence of the time delay on the duration of the starting signal, the relay is equipped with an additional resistor connected in series to the capacitive branch of the second arm of the bridge, and the comparison circuit is made on a two-transistor analog of a single-junction transistor.