SU748805A1 - Pulser - Google Patents

Description

(54) PULSE GENERATOR

The invention relates to a pulse technique. A pulse generator is known that consists of controllable trigger and control of the circuit with time-dependent thermo-dependent elements of indirect heating 1. The disadvantages of such a device are its relative complexity and the need for choosing high temperature stability to choose thermostable time setting elements c. . identical parameters. The closest to the proposed technical solution is a pulse generator 2. Containing a bistable element, the input of which is connected to the output of the control voltage divider containing in at least one arm a thermodependent time setting element, the heater of which is connected to the load circuit of a bistable an item. The disadvantage of such a device is the relatively low stability of the oscillation period. The purpose of the invention is to increase the stability of the oscillation period. For this purpose, an additional thermodependent sneMeHTi which is connected between the poles of the HCTO4Hifea directly or through a resistor and has a thermal connection with the thermodependent time of the master element of the pulse generator is introduced into the pulse generator. The additional thermostable element has a thermal connection with the bistable elements. Diagram of the pulse generator shown in the drawing. The pulse generator consists of a bistable element, such as trigger 1 and a control circuit including a resistor 2 and a time specifying a thermo-dependent element 3, the junction point of which is connected to the trigger input. In the load circuit of the trigger included heater 4 thermodependent element 3.

The thermo-dependent element 5, which is the heater of the case in which the locking element 3 is enclosed, is switched on by the poles of the power source either directly or through a resistor B.

The generator works as follows

In the half-period of oscillations, when the left half of the trigger 1 is open, the thermo-dependent element 3, having a negative temperature coefficient, is heated from the preheater 4, as a result of which the voltage at the trigger input (or the current when the current is controlled) decreases in absolute value. At a certain value of this voltage, corresponding to the trigger threshold, the trigger goes into a state in which its left half is closed. The element 3 begins to cool and the absolute value of the voltage at the trigger input is cooled at a value equal to the tipping voltage, after which the trigger returns to its original state. Then the process is repeated,

The temperature of the casing in which element 3 is enclosed is higher than the ambient temperature and does not depend on it due to the fact that the temperature-dependent element 5 in a narrow temperature range has a large (positive or negative) temperature coefficient of resistance (several tens of percent per degree). If the temperature coefficient is positive, then with an increase in the temperature of the medium, the resistance of element 5 increases and the overheating of the body relative to the temperature of the medium decreases, stabilizing the temperature of the body. With a negative temperature coefficient of the element. 5 in series with it, it is necessary to turn on a resistor 6. In this case, with an increase in the temperature of the medium, the resistance of the element 5 decreases, which reduces the case overheating, stabilizing its temperature. The temperature stability is further increased by connecting element 5 not to a voltage source, but to a current source. In the particular case, individual or all elements of a trigger can be enclosed in a housing along with element 3,

Element 5 may be made of a material based on barium titanate or vanadium oxides, which have large temperature coefficient values.

resistance in a narrow temperature range

Structurally, the thermistor - ele- -. The cop 5 can be given the shape Koj pus of the time of the setting element 3. For devices on discrete elements, it is advisable to enclose the casing in a sealed enclosure,

With a bridge control circuit (when a resistor 2 is replaced with a second time specifying or simply a thermo-dependent element) two thermally dependent elements can be applied in two different housings or combined in one common case with one additional element 5, which is more expedient. When the ambient temperature changes, the case temperature changes by units of degrees, which ensures a high stability of the oscillation period of the multivibrator and a wide range of operating ambient temperatures. With a certain choice of resistances of elements 2 and 3, the multivibrator can also operate in standby mode when triggered by an external pulse, where the increase in stability is even more significant.

invention formula

Claims (1)

1, a pulse generator containing a bistable element, the input of which is connected to the output of a control voltage divider containing, in at least one arm, a thermodependent time setting element, the heater of which is included in the load circuit of the bistable element, characterized by In order to increase the stability of the oscillation period, an additional thermo-dependent element is inserted in it, which is connected between the poles of the source directly or through a resistor and has a thermal connection with the thermo-dependent time cop, 2, Pop generator, 1, which is also distinguished by the fact that the additional thermo-dependent element has a thermal connection with the bistable element, Sources of information taken into account in the examination 1, Copyright certificate № 31036 L. CL, H 03 K 3/02, 1971, 2, On, Semiconductor devices in the technique of electrical communication, ed. Nikolaevsky, vol., 6, 197О, с, 178-179.