SU1541610A1 - Redundant quartz oscillator - Google Patents

Abstract

The invention relates to communication technology and can be used in radio engineering installations for various purposes in the construction of highly reliable generators. The purpose of the invention is to increase the speed of switching the backup channels and simplify the design of the device. The redundant crystal oscillator contains generators 1 ... 3, shapers 4.6 pulses, blocks 5.7 of the control, element 3-OR NOT 8. 3 Il.

Description

Schig.1

31

The invention relates to communication technology and can be used in radio installations in the construction of highly reliable generators. The purpose of the invention is to increase the speed of switching the backup channels and simplify the design of the device.

FIG. Figure 1 shows the block diagram of the backup quartz generator; in fig. 2 is an electrical circuit of a redundant crystal oscillator; in fig. 3 timing diagrams for generator operation.

The redundant crystal oscillator (FIG. 1) contains redundant generators 1-3, a pulse shaper 4, a control unit 5, a pulse shaper 6, a control block 7, a Z-OR-NE element 8, an output 9 of the device.

Redundant generators 1–3 (FIG. 2) are unsynchronized quartz oscillators designed to form a high-frequency (w / h) pulse sequence at their outputs and contain 1 for the generator — resistors 10 and 11, HE element 12, crystal resonator 13, capacitor 14, in / h choke 15, resistor 16, capacitor 17 and the element HE 18; for generator 2, resistors 19 and 20, HE 21, quartz resonator 22, capacitor 23, V / h choke 24, resistor 25, capacitor 26 and HE 27; For generator 3, resistors 28 and 29 are HE 30, quartz resonator 31, capacitor 32, V / h choke 33, resistor 34, capacitor 35, and HE 36.

Shaper 4 and 6 pulses (figure 2) are designed to generate a signal like a square wave and a double repetition frequency with respect to the input frequency and contain for the shaper 4 - HE elements 37 and 38, resistor 39, capacitor 40, HE element 41, resistor 2, capacitor 43, elements HE 44 and 45 and NAND 46; for the former 6, the elements are HE 47 and 48, the resistor 49, the capacitor 50, the element HE 51, the resistor 52, the capacitor 53, the elements HE 54 and 55 and AND-NOT 56.

The control blocks 5 and 7 (FIG. 2) contain for block 5 - block 57 standby multivibrators, capacitor 58, resistor 59, capacitor 60, resistors

five

0

five

Jq

Q

0

35

45

61 and 62, AND-NOT elements 63 and NOT 64; for block 7 - block 65 standby multivibrators, capacitor 66, resistor 67, capacitor 68, resistors 69 and 70, AND-NE 71 and HE 72 elements.

The generator works as follows.

The pulse sequence from the output of the generator 1 (fig.Za) is fed to the shaper 4, which at its output generates a signal of the type square wave with a double repetition frequency with respect to the input frequency (fig.3b, c, d, e, e). This sequence is fed to the input of block 5, in which the leading and trailing edges of each pulse, beginning with the first, start, respectively, the first and second waiting multivibrators (Fig.Zh.z).

The logical multiplication of these pulses leads to the formation of control signals of logical 1 (fig.Zi), and the inversion of logic pulses O (fig.Zk) on the outputs of block 5.

These signals, respectively, arriving at the first input of the first element AND element ZI-OR-NO 8 allow the passage of the pulse sequence of the crystal oscillator 1 to the output of the element 8 and prohibit the passage of the pulse sequence of generators 2 and 3 to the output of the element 8.

The second chain works in a similar way, containing a shaper of 6 pulses and a control unit 7. Under the action of the pulse sequence from the crystal oscillator 2, the outputs of block 7 form a logical 1, which prepares the second element And element 8 for operation and a logical O, which prohibits the passage of the pulse sequence from the generator 3.

When the quartz oscillator 1 fails, which corresponds to the absence of the next pulse at the input of block 5 (Fig. 3e), the waiting multivibrators are reset to the initial state (Fig. 3i) in a time equal to the RC time constant, which is more than half the frequency of the quartz oscillator 1.

In this case, the logical O, removed from the output of the control unit 5 (FIG. 3i), closes the first element AND of the element 8, and the inversion of the logical O, removed from output 2, opens

51

the second element And element 8, allowing passage of the pulse sequence of the crystal oscillator 2 to the output of element 8.

When a quartz oscillator 2 fails, which corresponds to the absence of the next pulse at the input of block 7 (Fig. Ze), logical O, removed from output 1 of control unit 7, closes the second element of Element 8, and inversion of logical O, removed from output 2 , opens the third element And element 8, allowing the passage of the pulse sequence of the crystal oscillator 3 to the output of element 8.

Claims (1)

Therefore, when using three quartz oscillators, switching from a faulty oscillator to a serviceable one is performed automatically, and when the three oscillators are operational, only the first oscillator is connected. Invention Formula Redundant crystal oscillator containing first or third backup 0 6 five 0 five 106 viral generators, the first and second control units and the ZI-I element; AND –NE, whose output is the generator output, characterized in that, in order to improve performance and simplify the generator, it contains the first and second pulse drivers, the first and second outputs The second redundant generators are connected to the inputs of the first and second pulse shapers, respectively, whose outputs are connected to the inputs of the first and second control units, respectively; the outputs of the first and third redundant generators are connected to the first by the moves of the first and third elements, respectively, of the ZI-OR-NOT element, the second input of the first element AND of the ZI-OR-NO element is connected to the first output of the first control unit, the second output of which is connected to the second inputs of the second and third element of the ZI-OR- element NOT, the third inputs of which are connected respectively to the first and second outputs of the second control unit. -w wtf ± cSp, w 6s Trf.  X x u -JLJLJLJLJI Tle P U Shigz