SU1485379A1 - Crystal oscillator - Google Patents

Description

The invention relates to radio and m. used as a source of electrical oscillations. The purpose of the invention is to increase the frequency stability of the generated oscillations and to increase the reliability of the start5 75

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PATENT TECHNICAL

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ka The generator contains a transistor 1, an inductor (CI) 2, a cond-ry 3, 4, 10, 15, a quartz resonator 7, compensating CI 8, resistors 11, a resistive voltage divider 13, a frequency control element 14. Parallel LC circuit 5, CI 9, resistor 12 are inserted into the generator. CI 9 and cond-15 form a sequential HC circuit 17 _? The introduction of the HC-circuit 5 into the collector circuit of transistor 1, as well as sequentially the HC-circuit 17 into an additional positive feedback circuit, allows to reduce phase shifts caused by various destabilizing factors, to increase the regeneration coefficient and, as a result, increase stability frequency of oscillations generated and reliability of launch 1 il.

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The invention relates to radio engineering and Nike and can be used as a source of electrical oscillations "

The purpose of the invention is to increase the frequency stability of the generated oscillations and increase the reliability of the launch.

The drawing shows a circuit diagram of a quartz generator.

The quartz oscillator contains a transistor 1, the first inductor 2, the first 3 and second 4 capacitors, parallel to the HC circuit 5, which contains the inductor 6, the quartz resonator 7, compensating. inductance coil 8, second inductance coil 9, third capacitor 10, first resistor 11, 20

the second resistor 12, the resistive voltage divider 13, the frequency control element 14, the fourth capacitor 15. The coil 2, the first 3 and the second 4 capacitors form a load 25 parallel HC circuit 16. The second coil 9 and the fourth capacitor 15 form a sequential HC circuit 17.

The quartz generator operates in the following manner.

The oscillatory system in the collector circuit of the transistor 1, consisting of a parallel parallel ιό HC circuit 16 formed by the first coil 35 2, the first 3 and second 4 capacitors, and a parallel HC circuit 5 containing the coil 6, tuned to the frequency of the mechanical harmonic of the quartz resonator 7. 40

Positive feedback voltage through element 14, a quartz resonator 7, shunted by a compensating coil 8, and a third capacitor 10 is fed to the emitter of the transistor 45 of the torus 1. Serial bc circuit 17 formed by the fourth capacitor 15 and the second coil 9 inductively connected to the compensating coil 8 , together with the second resistor 12, create an additional adjustable positive feedback circuit (with appropriate phasing of the second coil 9 and the compensating coil 8). This circuit allows you to enter the positive feedback connection, variable by means of the second resistor 12, into the base circuit of transistor 1 and eliminate the effect of the change in dynamic resistance of the quartz oscillator resonator 7 (in this α-batch) on the amplitude excitation conditions, and also to compensate its change for different numbers of mechanical harmonics,

The connection of the load parallel LC circuit 16 and the parallel LC circuit 5 in the collector circuit of transistor 1, as well as the connection between the compensating coil 8 and the second coil 9 is selected close or equal to the critical one. With such a connection, the phase-frequency characteristic has a horizontally located part within rather large limits of relative detuning.

Thus, the introduction of a parallel LC circuit 5 into the collector circuit of transistor 1, as well as a consecutive LC circuit 17 into an additional positive feedback circuit, allows to reduce phase shifts resulting from the influence of various destabilizing factors, to increase the regeneration factor, as a result, to increase the frequency stability generated oscillations and increase the reliability of the ups.

Resistor. Separator 13 and the first resistor 11 provide the mode of the transistor 1 DC.

Claims (1)

Claim A quartz oscillator containing a transistor whose emitter is connected to the common bus through the first resistor, a resistive voltage divider connected between the power line and the common bus whose outlet is connected to the base of the transistor, the first inductor which is connected between the power line and the collector of the transistor, the first and the second capacitors, the first terminals of which are connected respectively to the collector of the transistor and the power bus, and the second terminals of which are combined, serially connected control element second quartz resonator, and the third capacitor -kompensiruyuschuyu inductor which is connected in parallel a quartz resonator and a fourth capacitor, the second terminal member uprav1485379 6 The frequency is connected to the combined second terminal of the first and second capacitor, and the second output of the third capacitor is connected to the emitter, a transistor, characterized in that, in order to increase the frequency stability of the generated oscillations and increase the start reliability, a parallel LC circuit is introduced; which is connected to a common bus whose inductance coil is inductively connected to the first inductor, the second inductor, the first output of which is connected to the common bus, and the second output of which is connected None with the first output of the fourth capacitor, the second resistor, which is connected between the base of the transistor and the second output of the fourth capacitor.