SU1691924A1 - Crystal oscillator - Google Patents

Abstract

This invention relates to radio engineering and can be used in highly stable sources of electrical signals. The purpose of the invention is to increase the reliability of excitation of vibrations. The quartz generator contains the first and second transistors 1 and 2, a quartz resonator (CR) 3, the first and second resistors 4 and 5, the capacitor 6, the third and fourth transistors 7 and 8, and the inductance coil 9. KP 3 and the active part made on the first, second, third and fourth transistors 1, 2. 7 and 8, the first and second resistors 4 and 5, form an auto-oscillator ring in which oscillations are set, the frequency of which coincides with the frequency of tuning the parallel circuit, formed by capacitor 6 and coil 9. The goal is achieved by increasing the negative resistance of the active part. 1 il.

Description

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The invention relates to radio engineering and can be used in sources of highly stable electrical oscillations.

The purpose of the invention is to increase the reliability of excitation of vibrations.

The drawing shows a circuit diagram of a crystal oscillator.

The quartz generator contains the first and second transistors 1 and 2, the crystal resonator 3. The first and second resistors 4 and 5, the capacitor b, the third and fourth transistors 7 and 8 and the coil 9 inductance.

Quartz generator works as follows.

When the supply voltage is turned on, the first and second transistors 1 and 2. as well as the third and fourth transistors 7 and 8 are set to the active mode. The quartz resonator 3 and the equivalent negative resistance of the active part connected to its terminals form an oscillator ring in which oscillations of the fundamental frequency of the quartz resonator 3 or its harmonic are set, to which a parallel LC circuit formed by capacitor 6 and coil 9 is tuned.

The increase in starting reliability is achieved by increasing the equivalent negative resistance of the active part, the DC mode of which is provided by selecting the resistance of the first and second resistors 4 and 5.

Claims (1)

Invention Formula Quartz oscillator containing the first transistor, the second transistor, type the conductivity of which is opposite to that of the first transistor, the first resistor connected between the first power bus and the emitter of the first transistor, the second resistor, the first output of which is connected to the second power bus, a quartz oscillator, the first output of which is connected to the base of the first transistor and the base of the second transistor, capacitor, the first output of which is connected to the emitter of the second transistor, characterized in that, in order to increase the reliability of excitation of oscillations, a third transistor is introduced, the collector of which is connected to the second output of the second cut emitter to the collector of the first transistor, the fourth transistor, the type of conductivity of which is opposite to the type of conductivity of the first transistor, the inductor, which is included parallel to the capacitor, with the emitter of the fourth transistor connected to the second output of the second resistor, and the collector of the fourth transistor connected to the emitter of the second transistor, the second output connect the quartz oscillator to the base of the third transistor and the base of the transistor transistor, the collector of the second transistor is connected to the emitter of the first transistor, the second output of the capacitor is connected to the collector of the first transistor.