SU894833A1 - Pulse generator - Google Patents

Description

one

The invention relates to a pulse technique. The generator can be used as an optocoupler static (in memory mode) and dynamic memory (in generation mode), as a generator in analogue settings. digital time-pulse converters, such as a clock pulse generator in the opto-circuitry of automation and computer technology, and so on.

A pulse generator is known that contains an amplifier on a transistor, the input of which includes the back-up RC circuit, two optocouplers with an electroluminescent diode and photodiodes each, with the electroluminescent diode of the first optocoupler in the forward direction in the zmitter circuit of the transistor, and electrolumines, a second diode of the second optocoupler connected to the source of the control signal, the photodiode of the first optocoupler is connected in reverse polarity between the power supply and the connection point of the resistance and the capacitor of the KS circuit, and the photodiode The second optocoupler is connected in reverse polarity between the power supply and the base of the transistor l.

The known pulse generator containing a transistor, in the emitter circuit of which an LED is on, the base of the transistor is connected to one power supply bus through a resistor, and to the other through a collector-emitter junction of an additional transistor, the base of which is connected to a collector through a photoresistor

to the main transistor, and through the resistor to the power bus (2.

However, known generators cannot be used as memory elements.

15

The purpose of the invention is to expand the functional capabilities of the generator, which consists in using it as a memory element.

20 To achieve this goal, a pulse generator containing keys connected in series to a power supply circuit and a LED, a control key switch are connected to a corresponding power supply source through photodiode connected optically to the LED and to a control voltage source and also that the control electrode of the key

connected to a control voltage source through a resistor.

The drawing shows a schematic diagram of a pulse generator.

The generator contains a key, for example, on a transistor 1, connected according to the scheme with a common emitter, resistor 2, connected between the base of the transistor. and a control voltage source 3, an LED 4, connected to the collector circuit of transistor 1, optically coupled to the LED 4 photodiodes 5 and 6, forming an anti-series circuit connected between the base of the transistor 1 and the power supply glue 7 (Unii " n)

The generator works in the following way.

In the generation mode, terminal 7 is connected to Lln & mi and positive voltage is applied from source 3. When the supply voltage is switched on, due to the positive bias applied to the base of transistor 1 through resistor 2, transistor 1 opens and reaches us. At this moment, a current IK I then flows through the LED 4 (I then is the threshold value of the current of the LED 4), which emits a light flux. The emission intensity of the LED 4 must meet the condition of S 1 (where the ultrasonic amplification factor of the transistor, JS is the optical coupling coefficient) at which the peak of the pulse is formed. The duration of the vertex is determined by the inertia of the photodiodes 5 and b. The formation of the pulse tip ends after the photodiode b is fully opened. The process of resorption of charges from the base area of transistor 1, which is closed, begins. The rising edge of the pulse is formed. From the moment of complete cut-off of transistor 1, a pause between pulses begins, the duration of which depends on the circuit relaxation due to the RC parameters of LED 4, transistor 1 and resistor 2. When the base potential exceeds the potential of the emitter by a certain amount, the transistor opens and the whole process repeats. By changing the magnitude of the polarizer voltage of source 3, it is possible to vary the charging time of the capacitances of the pn-junctions of the svatodiode and the transistor, and hence the pulse frequency.

In memory mode, terminal 7 is connected to + Untim from the source

3 pulses of different polarity of a certain duration are applied. When a positive-polarity pulse is applied from source 3, transistor 1 opens and causes f to illuminate LED 4, which, illuminating the photodiodes 5 and b, begins to open photodiode 5, creating positive feedback. As a result, the base current is further increased during

Q power supply count, "transistor 1 enters saturation mode. After termination of the input pulse in this excited state, the generator can be indefinitely long. When served from source 3

5 the negative polarity pulse transistor 1 is closed, its current decreases, which leads to the break of the positive feedback circuit, and the generator goes to unexcited

0 state.

LED 4 can be included in the emitter circuit of the transistor.

Thus, the proposed generator can be used both as a generator and as a sign of one element without internal adjustment. In addition, the absence of capacity makes it possible to manufacture it in an integral form in a single technical design.

Claims (2)

1. A pulse generator, comprising successively connected cliques and an LED in the power supply circuit, characterized in that in order to expand the functional possibilities, the control electrode The 0 key is connected to the corresponding power supply bus through anti-sequential photodiodes optically coupled to the LED and to the control source 5 voltages 2. The generator according to claim 1, characterized in that the control electrode of the switch is connected to the control voltage source through a resistor. Sources of information taken into account in the examination 1. USSR author's certificate No. 307499, cl. H 03 K 3/42, 1970. 2. Authors certificate of the USSR 630733, cl. H 03 K.3 / 281, 1977 (prototype). 7-w Pete  -tfftw