SU1660149A1 - Pulse driver - Google Patents

Description

The invention relates to a pulse technique and can be used in automation and control devices for

signal generation with induction sensors. The aim of the invention is to expand the functionality by forming pulses from a sequence of input signals with decreasing amplitude. The device contains diodes 1 and 2, A-diode, pn-p-transistor 4. pn-p-transistor 5, resistors 6-8, capacitor 9 and matching element 10. The operation of the device is illustrated by time diagrams given in the description inventions, 1C. f-ly, 3 ill.

1660149

1660149

The invention relates to a pulse

technology and can be used in devices of automation and control for

signal generation with induction

sensors.

The purpose of the invention is to expand the functionality by ensuring the formation of pulses from a sequence of input signals with decreasing amplitude.

Figure 1 shows the diagram of the pulse shaper; figure 2 is a diagram of a matching element, made on an optoelectronic pair; on fig.Z - time diagrams of the voltages on the circuit elements, input and output signals of the pulse shaper.

The pulse shaper contains the first and second diodes 1 and 2, L-diode 3, pn-p-transistor 4, pn-p-transistor 5, three resistors 6-8, capacitor 9 and matching element 10. To the input 11 pulse shaper connected through the third resistor 6 anode of the first diode 1 and serially connected second diode 2 and λ-diode 3 base pn-p-transistor 4, which is also connected to the common bus through resistor 7. The emitter is connected to the cathode of the first diode 1 pp transistor 5, the first capacitor plate 9 and through a resistor 8 collector ppp transistor 4. Base pnp transi Store 5 is connected to the collector pr-p-transistor 4, and the collector - with the first input of the matching element 10, the outputs of the latter are connected to the output of the pulse shaper. The second input of the matching element 10, the second plate of the capacitor 9 and the emitter pn-p-transistor 4 are connected to a common bus 12 pulse generator.

The matching element 10 can be made on an optoelectronic pair, including the emitter (LED) 13, the fiber optic light guide 14 and the photodetector 15, with the inputs of the emitter 13 connected to the inputs of the matching element 10, and the outputs of the photodetector 10 are connected to the outputs of the matching element 10. As matching element 10 can also be used a resistor, the value of which is chosen based on a given current in the load and the level of the input signal.

The pulse shaper operates as follows.

Until the input signal ΙΗ ι, the capacitor 9 is discharged; _The output voltage U s PFN is zero. At the time ίι (fig.Z) a positive half-wave of sinusoidal voltage Tsz enters the input 11 of the device. Until time point X2. The input voltage applied to the λ-diode 3 is less than its pickup threshold and λ-diode 3 has a high conductivity, while transistor 4 is open and transistor 5 is closed, since the voltage drop across resistor 8 is not enough to open it. .B5 voltage U _e applied to the emitter junction of the transistor 5 is determined by the formula

Tse.b5 = ϋ 11 - 1) b - CD - and ι, where Tse - voltage drop across the resistor

6, B;

C1 - voltage drop on the first diode 1, V;

U - voltage collector - emitter of transistor 4, V

To ensure reliable closing of the transistor 5, it is necessary that the pickup voltage of the λ-diode 3 (i.e., the voltage at which the λ-diode 3 goes from a conducting state to a state with low conductivity) does not exceed the voltage level 1), defined by the formula

and _c = it + n + i + i + and _e. b5 - (i + w). where Tsg is the voltage drop on the second diode 2, V;

□ γ - voltage drop across the resistor.

7 equal voltage) emitter - base D _e .b. transistor 4, causing unlocking of the next, B.

At the moment of time \ 2 λ-diode 3 goes into a state with low conductivity, transistor 4 is locked, the voltage on the anode of the first diode 1 increases abruptly (Fig.Zb), the capacitor 9 starts charging (Fig.Sv). The charge of the capacitor 9 continues until the time Tz, in which the diode 1 is locked. During the interval 3 ~ ΐ4, the voltage on the capacitor 9 decreases due to its discharge, caused by the presence of leakage resistance, and also due to the reverse currents of the collector junction of the transistors and the final insulation resistance. At the moment of time, the input signal Tsc (fig. 3a) reaches the voltage C _{n of the} switching of the diode 3 from the state of low conductivity to the state of high conductivity. Transistor 4 opens and remains open during the entire switching time of λ diode 3 until the moment when the voltage at the junction emitter - the base of transistor 4 becomes - is not less than the voltage unlocking the latter. Since the voltage drop Tse on the resistor 8 is sufficient for unlocking the transistor 5, the latter opens and the capacitor 9 is discharged on co.

shuffling element 10 (fig.Zv, moment of time m). At the output of the matching element 10, a voltage pulse appears (Fig. 3g). During the passage of the negative half-wave voltage, the diodes 1 and 2 are locked and the driver does not work.

Claims (2)

Claim 1. The pulse shaper containing a capacitor, pnp transistor, the first and second resistors and the first diode, to the cathode of which the first capacitor plate is connected and through the first resistor to the npp transistor, the base of this transistor the second resistor, and the emitter is directly connected to the common bus of the driver, characterized in that, in order to extend the functionality, a pnp transistor, a second diode and an L diode, a third resistor and matching element, with the anode of the first diode connected to the input of the pulse shaper, and through the second diode and A-diode connected in series - the base of a pnp transistor, the emitter of a pnp transistor connected to the cathode of the first diode, its base is connected to the collector of a pnp transistor, and the collector is connected to the first input of a matching element, and the second capacitor plate is connected to the common bus of the driver. 2. Shaper according to claim 1. of those who are with me. that the matching element is made in the form of an optoelectronic pair, including the emitter, the light guide and the photodetector, the emitter pins connected to the inputs of the matching element, the photoreceiver pins connected to the outputs of the matching element, and the emitter and photodetector are optically coupled to the light guide. FIG. 2