JPS5845211B2 - oscillation circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an oscillation circuit comprising an astable multi-byte break circuit that uses inductance and exhibits stable performance.

Conventionally, as oscillation circuits using inductance, there are LC oscillation circuits such as Colpitts circuits and Hartley circuits, but these have drawbacks such as large limitations due to oscillation conditions and a small oscillation range.

The present invention provides a stable oscillation circuit that is less limited by oscillation conditions and has less drift due to temperature and voltage.

Embodiments of the present invention will be described below with reference to the drawing of FIG.

In the figure, E is a DC power supply with voltage VB, and IC.

IC2 is an inverter such as CMO8 or MOS whose input impedance is higher than output impedance, L is an inductance, and R is a resistance.

Then, inverter E C1 and ■C2 are powered by DC power source E.
The output side of inverter ■C1 is connected to the input side of inverter ■C2.

In addition, the inductance L is connected between the input side and the output side of the inverter ■C1, and the resistor R is connected between the inverter ■C1 and the output side.
It is connected between the input side of C1 and the output side of inverter IC2.

Note that OUT is an output terminal.

The inverters (2)C1 and (2)C2 may be replaced by NAND circuits or NOR circuits, as long as they are elements (including device circuits) whose input and output logics are inverted.

The present invention will be explained by taking an inverter as an example.

Next, the operation of the circuit shown in FIG. 1 will be explained.

When the output ■ of the inverter IC2 is logic = 1 (hereinafter referred to as H), the input via the resistor R is H.

Therefore, the output ■ is logic=0 (described as follows).

Assuming that, when this state is reached, ■ suddenly rises as shown in part A of ■ in FIG. 2, the power supply voltage vB of the power supply E is suddenly applied to both ends of the inductance L.

When a DC voltage vB is suddenly applied to a series circuit of inductance L1 and resistor R as shown in Fig. 3 by closing switch S, the transient phenomenon does not change with time t as shown in Fig. 4. As is well known.

Therefore, the waveform of the input to the inverter IC1 gradually decreases from VB as shown by ■ in FIG.

This is because the voltage across the inductance L gradually decreases.

Then, when the input voltage reaches the time point b in FIG. 2, it drops to the threshold voltage vth of the inverter IC0.

Since the output of the inverter (2) C1 is inverted from L to H at the threshold voltage vth, the outputs (2) and (2) are respectively inverted to H as shown in FIG.

As a result, a voltage vB is applied to the series circuit of the inductance L and the resistance R with the opposite polarity to that at point a in FIG. However, as time passes, the voltage across the inductance L decreases until it reaches the point C in FIG.

At this point e, the input of inverter ■C1 is again vt
h, so in this circuit similar to that from time a, positive feedback is applied to the series circuit of inverter C0 and IC2 by resistor R, and oscillation continues.

Furthermore, the reason that ■ in Fig. 2 suddenly reverses at each time point a, b, c, and d is due to the fact that inverters IC1 and IC2 have high gain input/output characteristics as shown in Fig. 5. ing.

Note that the time constant in the circuit of FIG. 1 is L/R, and as the inductance L becomes larger and the resistance R becomes smaller, the oscillation period becomes longer.

In extreme cases, there is no problem even if the resistor R is short-circuited, but since the output impedance of the inverter IC2 acts as a series resistor, there is a limit to how long the cycle can be lengthened by reducing the resistor R.

In addition, in order to stabilize the voltage characteristics of oscillation, there is a connection point between inductance L and resistor R, and an inverter IC.

The same operation will occur even if another resistor is inserted in the line between the input side and the input side.

If it is desired to make the period even longer, insert a capacitor C in parallel with the inductance L to form a type of tank circuit as shown in FIG. 6, and a relatively long period of oscillation can be obtained.

The oscillation circuit according to the present invention based on the above configuration and principle performs extremely stable oscillation, has a small number of component parts, is inexpensive, and has excellent industrial efficiency.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the oscillation circuit according to the present invention, FIG. 2 is a voltage waveform diagram at each part of FIG. 1, and FIG. 3 is an L-R series circuit for explaining the oscillation circuit of the present invention. Figure, 4th
3 is a transient phenomenon characteristic diagram of the circuit of FIG. 3, FIG. 5 is an input/output characteristic diagram of the inverter in the circuit of FIG. 1, and FIG. 6 is a circuit diagram of another embodiment of the oscillation circuit according to the present invention. E: DC power supply, IC1: first element (inverter), IC2: second element (inverter), R: resistor, L- ...Inductance, C... Capacitor.

Claims (1)

[Claims] 1 It has a first element and a second element whose human power impedance is higher than the output impedance and whose input and output logics are reversed, and the output side of the first element is connected to the input side of the second element. and connect the inductance to the first
An oscillation circuit characterized in that an oscillation circuit is connected between an input side and an output side of an element, and a resistor is connected between an input side of the first element and an output side of the second element.