JPS6022524B2 - oscillator - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oscillator using a semiconductor element (for example, a bipolar transistor, a field effect transistor, etc.).
In particular, it relates to a high-frequency oscillator that can oscillate using a commercial AC power source as a direct bias power source.

However, this type of device required extra equipment because it required a storage battery, dry cell battery, or a commercial AC power source that was stepped down or stepped up using a transformer and then converted to DC using a rectifier circuit.

A rectifier circuit used in a conventional high-frequency oscillator will be explained below using drawings. FIG. 1 is a circuit diagram showing an example of a conventionally used rectifier circuit.

In the figure, there is a commercial AC voltage of 100V at terminal 1,
200V is applied, the voltage is stepped up or down by the transformer 2, the alternating current is full-wave rectified by the bridge circuit 3 made up of four diodes, the alternating current is converted to direct current by the capacitors 4a and 4b and the inductor 5, and the terminal 6, a DC voltage appears.

The oscillator can be operated by connecting an oscillator (not shown in the figure) using a semiconductor to serve as a load for the power supply. FIG. 2 is a circuit diagram showing an example of a conventionally used half-wave rectifier circuit. This circuit uses diode bridge 3 instead of full wave rectification in Figure 1.
It adopted half-wave rectification with 31 leads, and the other parts were the same as those in Figure 1. In either case, the rectifier circuit uses the transformer 2, capacitors 4a, 4b, and inductor 5, so depending on the operating voltage and power of the high-frequency oscillator serving as the load, the power capacity of the transformer 2, the operating voltage of the capacitors 4a, 4b, The current capacity of the inductor 5 is limited. In particular, when the transformer 2 is used for electric power, it becomes large, and the inductor 5 and capacitors 4a and 4b also become correspondingly large, which also has the drawback of increasing the price. That is, when trying to make a small oscillator, semiconductor elements such as diodes and transistors are small enough to pose a problem, but miniaturization is always constrained by the transformer, capacitor, and inductor of the power supply circuit. In order to eliminate these drawbacks, the present invention aims to provide an oscillator that can generate high-frequency oscillation by directly applying a commercial AC voltage without going through a transformer.

FIG. 3 is a circuit diagram of a high frequency oscillator showing an embodiment of the present invention, and the principle of operation will be explained below.

Terminals A and IB, which are connected to a commercial AC power supply, are equipped with semiconductor elements, namely field effect transistors FET, ? A and 7B are connected via diodes 3A and 3B, respectively.

Although it is suitable as the one in Fig. 2 in that it performs half-wave rectification using a power rectifier diode 3A or 38,
Not only the power transformer 2 but also the filter capacitors 4a and 4b
And since the low-frequency inductor 5 is omitted, the oscillation circuit on the A side in Figure 3 can only provide an oscillation output for half a cycle of the AC power supply. Efficient operation is possible by operating the oscillation circuit on the B side in the figure.The AC voltage applied to the terminals IA and IB causes current to flow through the diode 3A during a half cycle, but not through the diode 38.

While the current is flowing through the diode 3A, the FETF is 7A.
Inductor box A as shown in the figure is oscillated by
, 9A, an FET, a parasitic capacitance OAY IIA of 7A, and a bias resistor 12A are connected to form a Colpitts circuit. The capacitor 13A blocks commercial AC power, and the inductor A is a high frequency choke coil that blocks high frequencies. In the remaining half cycle, no current flows through diode 3A, but current flows through diode 3B.

Oscillation circuit B is designed exactly the same as oscillation circuit A.
B, 148, followed by a bias resistor 128. 1
6 is a high frequency transformer that connects the outputs of oscillators A and B to terminal 16.
and the load connected to it.

FIG. 4 shows the relationship between the above-mentioned high frequency oscillation output (vertical axis) and time (horizontal axis). The oscillator A operates during T'2 of the period T of the commercial AC cycle, and the remaining T'2
During this period, the oscillator B operates, and the oscillation output appears at the terminal 16 alternately at the period T of the commercial cycle. With such an oscillator configuration, high-frequency oscillation is possible without a transformer or a power supply rectifying capacitor or inductor, making it possible to create a small and inexpensive oscillator.

Only the current capacities of the diodes 3A and 3B are related to the output power. Since semiconductors are generally small, if necessary, the design can be easily changed by connecting two or more semiconductors in parallel without increasing the volume. Although the operating voltage of this circuit is limited, a circuit with a high withstand voltage can be easily obtained by using a static induction transistor as a semiconductor that operates at commercial low voltage.
Furthermore, highly efficient oscillation is possible by using switching transistors. Examples of applications include oscillators for high-frequency electrodeless backlights, oscillators for high-frequency scales, and oscillators for microwave ovens.For applications that only use high-frequency power and the oscillation waveform is not a problem, commercial AC voltage can be directly applied. It is extremely convenient to use.

Although the above description has been made with the oscillators A and B having the same oscillation frequency, there is no problem even if the oscillators A and B have different oscillation frequencies.
Furthermore, although direct use of a commercial AC power source is most effective, it is also possible to reduce the size by changing the voltage via a transformer due to the filter circuit. ``If a slight increase in size is acceptable, a capacitor can be installed at the output of each diode.As detailed above, this invention uses two semiconductor oscillation circuits that can be made small. Since the above two oscillation circuits are operated alternately with half-wave rectified outputs from diodes connected to both terminals of the AC power supply, there is no need for a power transformer, an inductor, or a capacitor, resulting in a compact design. An inexpensive oscillator can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an example of a rectifier conventionally used as a power source for an oscillator, etc. Fig. 2 is a circuit diagram showing another conventional example; Fig. 3 is a circuit diagram showing an embodiment of the present invention. , FIG. 4 is a diagram showing the output waveform. In the figure, IA and IB are the first and second terminals of the AC power supply, respectively, and 3A? 3B are the first and second respectively
, A and B are first and second oscillation circuits, respectively, and 15 is a high frequency transformer. Note that the same symbols in the figures indicate the same or corresponding parts.Figure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] 1. The first diode connected between the cathode (or anode) of the first diode whose anode (or cathode) is connected to the first terminal of the AC power source and the second terminal of the AC power source, a first oscillation circuit that operates with wave rectified output; a cathode (or anode) of a second diode whose anode (or cathode) is connected to a second terminal of the AC power source; and a first terminal of the AC power source; an oscillator comprising: a second oscillator circuit connected between the oscillator circuit and the second oscillator circuit that operates with a half-wave rectified output from the second diode; and a high-frequency transformer that combines the outputs of the first and second oscillator circuits.