JPS5843012A - Power supply switching controller - Google Patents

Abstract

PURPOSE:To perform the power supply switching control with high efficiency through a simple constitution, by transmitting a switching instruction signal between the half wave and full wave conduction to the base of a transistor. CONSTITUTION:When a signal which turns on a transistor 18 is fed from a control terminal 21, a capacitor 17 is charged in a half period during which the terminals A and B are set at a positive and negative potential respectively. While the electric charge which is charged to a capacitor 17 is discharged through a diode 20 in a half period during which the terminals B and A are set at a positive and negative potential respectively. Thus a half wave conduction is performed. Then if the terminal voltage of the capacitor 17 exceeds a prescribed level when the transistor 18 is turned off, a thyristor 15 is triggered to deliver a full wave AC current to the area between terminals C and D.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is a power supply switching system that selectively switches between half-wave energization and full-wave energization in an AC source circuit. Therefore, it may be necessary to switch between half-wave energization and gold-wave energization in the power supply circuit. In such cases, conventionally, the AC power source is connected to terminal A, as shown in FIG. 11, for example.

3, and a load is connected between terminals C and D, one of the power supply lines is terminal 5, terminal 8.8.
A parallel circuit of a diode, a conductor 11, and a relay switch 12 are inserted between them. Then, the relay drive current input from the terminal 13 excites and controls the relay coil 14, so that the relay switch 12 is driven to be switched on or off, and in the on state, full-wave energization 17. Half-wave energization is performed in the off state.

However, since the above parallel connection circuit of diode 11, relay switch, and circuit J2 uses a relay to switch between half-wave energization and full-wave energization, it is not possible to control the timing of the first switching with high precision. First, consideration must be given to large currents when switching occurs at voltage peaks. Second, as mentioned above, since large currents are handled during on/off,
Relays with large contact capacity were required, and the contacts also deteriorated rapidly, which was economically disadvantageous.

This invention was developed in consideration of the above-mentioned points.It has a simple structure, high efficiency, and has % of the durability that can be achieved by switching between full-wave energization and half-wave energization according to the power supply phase. The present invention provides an excellent power supply switching control device.

An embodiment of Jin's invention will be described below with reference to the drawings.
, Fig. 2 shows its configuration.As in Fig. 1, AC power is supplied between input terminals A and B, and output terminals C and D.
A rectifier diode 11 is connected between the terminal 8 and the terminal D to supply power to the load, and allows only positive current to pass through. A thyristor 15 is connected in parallel with this diode 11 and has a polarity opposite to that of this diode 11.
is connected. A series circuit of a resistor 16, a capacitor 11, and a transistor 18 is connected in parallel; in this case, the transistor 18
forms a path for current flowing from, for example, to the cathode side. .

And, between the capacitor 1r and the transistor 18,
A Zener diode 19 is provided to detect the charging voltage of the capacitor 17, and the anode of the Zener diode 19 is connected to the r-to of the thyristor 15. Above transistor 1
8 is connected in parallel with a diode P2O, and this diode 20 is set to flow a current in the opposite direction to the transistor 18, and is used for discharging the capacitor 17. Reference numeral 21 is a control terminal for supplying a pace current to the transistor 18, which is a tortoise terminal that supplies a pace bias current during half-wave energization.

First, a case where a signal for turning on the transistor 18 is input from the control terminal 21 will be described. Terminal A
, B is supplied with an alternating current as shown in FIG. Potential: The cathode is at a negative potential. Therefore, through the transistor 18 which is in the on state, the
A charging circuit for capacitor 11 is formed.

Moreover, no potential difference occurs between both ends of the Zener diode 19, and the thyristor 15 is cut off! I! There is an IC.

Furthermore, during a half cycle in which the terminal B is at a positive potential and the terminal A is at a negative potential, a current flows through the diode 11 connected in parallel to the thyristor 15 which is in the disconnected state. Also, at this time, the charge that was stored in the capacitor 11 during the previous half cycle is discharged through the diode PI3. That is, when the transistor 18 is in the on state, the thyristor 1
The voltage waveform between the anode and cathode of No. 5 is shown in Figure 3 (b).
The charging voltage waveform of the capacitor 11 becomes as shown in FIG. 3(e) and the waveform of the capacitor charging current flowing through the transistor 18 as shown in FIG. 3(d).
K will be shown. Therefore, as described above, when the transistor 18 is in the on state, a current having a waveform as shown in FIG.

Next, when the transistor 18 is off, the terminal B is at a positive potential and the terminal B is in a half cycle of a negative potential, and a positive voltage is applied to the anode of the thyristor 15 and a negative voltage is applied to the cathode, IK causes the resistor 16 to A charging current is supplied to the capacitor 17 flowing through the capacitor 17, and when the terminal voltage of the capacitor 11 exceeds the Zener voltage of the Zener diode 19, the thyristor Ill/C? "-) signal is supplied. In other words, it is generated as shown in the dart signal line (r) Vc in FIG. 3, the thyristor 15 is triggered and becomes energized, and a negative half-wave current flows between the power supply line BD .

Also, if terminal B is positive and terminal A is negative, thyristor 15
is in a cut-off state, but when the transistor 18 is in the off state, as shown in FIG.
A low potential difference with a waveform as shown in FIG. 3(b) is observed, and a full-wave alternating current with a waveform as shown in FIG.

At this time, the values of the resistor 16, capacitor 11, and Zener diode 19, which provide current to the dart, must be set appropriately to the terminal A.

The thyristor is turned on immediately after the input potential between 8 and 8 exceeds zero potential, suppressing noise when the thyristor is turned on, and efficiently continuing switching.

As described above, 1. According to the present invention, when a command signal for switching between half-wave energization and full-wave energization is sent to the transistor pace with a small current, the thyristor is switched and controlled at a point close to the zero potential of the power supply. The load at the time of this switching is as follows.

It is possible to provide a simple and efficient power supply switching control device for half-wave energization and full-wave energization, which has a configuration in which noise, current, and noise when turning on a thyristor are reduced.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram illustrating a conventional rectification switching device for a power source, and FIG. 2 is a diagram showing voltage and current waveforms at various points according to an embodiment of the present invention. 11... Diode, 15... Thyristor, 11.
-・Capacitor, 1B-・Transistor, 19...
zener diode.

Claims (1)

[Claims] A series circuit consisting of a diode inserted into an AC power supply line, a thyristor connected in antiparallel to the diode, a capacitor and a transistor connected in parallel to the thyristor, and a transistor controlled by a switch, and the transistor A power supply switching control device characterized by a Zener diode which is turned on when the switch is turned on.