JPH0361206B2 - - Google Patents

Description

Detailed Description of the Invention The present invention uses a leakage type tripod transformer to insulate the power supply and the operating circuit, and also generates an electromotive force in the tertiary coil by controlling the secondary coil to create a bidirectional three-terminal thyristor. This relates to a circuit that controls the phase of AC power.

Conventionally, AC power control circuits using SCRs, triaxes, etc. were all connected in series to an AC power source as shown in Figure 1, and there was a risk of electric shock when controlling power. To solve this problem, when performing remote control from a low voltage operation circuit, when using a photocoupler non-contact relay as shown in Figure 2, a power supply is required for operation input, and even if on/off control is possible, phase control is not possible. Since this is not possible, a separate control circuit is required for phase control, making it even more expensive.

In order to solve these conventional drawbacks, the present invention uses a leakage type tripod transformer to insulate the operation switch and the power supply, and activates the tertiary coil by changing the resistance connected to the secondary coil and short-circuiting the switch. It controls the oscillation of the oscillation circuit consisting of a resistor, capacitor, and trigger element SBS by adjusting the power, subtracting or zeroing it, controls the phase of the bidirectional three-terminal thyristor, and controls the power of the load connected in series with it. .

Embodiments of the present invention will be described below based on the drawings.

FIG. 3 is a circuit diagram showing an AC power phase control circuit according to an embodiment of the present invention. Before entering into the explanation of this embodiment circuit, the leakage type tripod transformer 1 used here will be briefly explained.

As shown in Fig. 4, the leaky tripod transformer has outer legs 2 and 4 and a center leg 3 as the tripod core,
A gap 5 is provided on the outer leg 4. outer leg 2
A primary coil 6 is wound around the central leg 3, a secondary coil 7 is wound around the central leg 3, and the outer leg 4 with the other gap 5 is wound with a secondary coil 7.
A tertiary coil 8 is wound in each case so that a low voltage is induced therein.

In the embodiment circuit shown in FIG. 3, a variable resistor 12 and a switch 13 are connected in series to both ends of the secondary coil 7 of the leaky tripod transformer 1, and the primary coil 6, full-wave rectifier 14, resistor 15, and capacitor 16 are connected in series. A series circuit is connected in parallel to the power supply 17, a full wave rectifier 18 is connected to both ends of the tertiary coil 8, and a pulse absorbing capacitor 19 is inserted on the DC side of the DC output. A resistor 21, between the base and emitter of the transistor 20 connected to
A bidirectional three-terminal thyristor 2 is connected in series with a load 23 connected to a power supply 17 at the connection point between the resistor 15 and the capacitor 16.
A capacitor 26 and a resistor 27 are connected to the gate of the bidirectional three-terminal thyristor 24 via an SBS 25. 5 is a circuit in which the connection point C of the series circuit of the primary coil 6, full-wave rectifier 14, resistor 15, and capacitor 16 in FIG. 3 is connected to the connection point B of the load 23 and the bidirectional three-terminal thyristor 24. Other details are the same as in Figure 3.

Next, the operation of the leaky tripod transformer 1 will be explained. In FIG. 4, when the primary coil 6 is connected to the power source 17 and energized, if the secondary coil 7 is open, most of the primary magnetic flux φ ₁ is as shown by the solid line, and most of the magnetic flux φ ₁ ' flows through the central leg 3. The outer leg 4 with the gap 5 interlinks with the secondary coil 7 to induce a low voltage.
Since only a small amount of leakage magnetic flux φ ₁ ″ passes through the tertiary coil 8, only a very small voltage is generated in the tertiary coil 8. However, when the secondary coil 7 is short-circuited by the switch 13', a short-circuit current flows, and the magnetic flux φ ₁ ′ and A secondary magnetic flux φ ₂ in the opposite direction is generated, and the magnetic flux φ ₂ ″ on the outer leg 4 side and the outer leg 2
The magnetic flux φ ₂ ′ on the side is shunted as shown by the dotted line, and the composite magnetic flux of the magnetic flux φ ₁ ″ increased by the short circuit and the magnetic flux φ ₂ ″ passes through the outer leg 4 where the gap 5 is located, so that it is applied to the tertiary coil 8. As a result of linkage, a voltage is generated that lags the power supply voltage by a little less than 360 degrees. In other words, this tertiary voltage is the power supply voltage (sixth
It is considered that the voltage is slightly more advanced than the voltage (thin line A in FIG. 6) than the thick line A in the figure. As mentioned above, in response to a short circuit in the secondary coil 7, the leaky tripod transformer induces a voltage in the tertiary coil 8 that is 360 degrees delayed, that is, a voltage that is considered to be approximately in phase with the power supply, and that is slightly in advance. It has characteristics. Also, if you connect a variable resistor to the secondary coil and increase the resistance value from 0 ohm (corresponding to a short circuit), the short circuit current will decrease, and the tertiary voltage will decrease accordingly. can be controlled. The example circuit of FIG. 3 utilizes these specifications.

Next, the operation of the embodiment circuit shown in FIG. 3 will be explained. Note that FIG. 6 shows voltage waveforms at various parts of the example circuit. In the figure, A is a waveform diagram of the relationship between the power supply voltage (thick line) and the tertiary voltage (thin line, when the secondary is shorted); ),
C is the load voltage when B and B', D and D' are the pulse voltages applied between the triax G- _T1 when the secondary coil is short-circuited, and E is the waveform of the load voltage when D and D' are applied. It shows.

When the switch 13 is open, no voltage is generated in the tertiary coil 8 due to the characteristics of the tripod transformer described above. Therefore, since no voltage is applied between the base and emitter of the transistor 20, there is no conduction between the collector and emitter. Therefore, since no voltage is applied to the capacitor 16, it is not charged and the SBS 25 and bidirectional three-terminal thyristor 24 do not operate. However, when the switch 13 is closed, for example, the variable resistor 12
If is 0 ohm, it means that the secondary coil 7 is short-circuited, a voltage is generated in the tertiary coil 8, and the rectifier 1
The voltage rectified at 8 is applied between the base and emitter of the transistor 20, and the transistor 20 becomes completely conductive, and its internal resistance becomes extremely small.
An alternating current voltage is applied to 6, and when it is charged and exceeds the breakover voltage of SBS 25, it is discharged through gate G and terminal _T1 of bidirectional three-terminal thyristor 24. This action is repeated, resulting in an oscillation state. The transistor 20 performs charging and discharging every half cycle.
This is determined by the combined resistance of the internal resistance of the resistor 15 and the resistor 15, but in experiments, the number of oscillations was approximately 10 or less times. Gate G of bidirectional three-terminal thyristor 24, terminal
The voltage waveform between _T1 is as shown in Fig. 6D. As the resistance value of the variable resistor 12 increases, the secondary short-circuit current decreases and the voltage of the tertiary coil decreases, which is applied between the base and emitter of the transistor 20, so that the internal resistance between the collector and emitter gradually increases. As a result, the combined resistance value with the resistor 15 increases, and the number of oscillation circuits during a half cycle decreases, reaching a limit of 0. There are times when the voltage waveform between the gate G and terminal _T1 of a bidirectional three-terminal thyristor is as shown in FIG. 6B. Therefore, by changing the variable resistor 12, the charging time is delayed and the discharge timing changes in phase, and the first discharge of a half cycle becomes the turn-on current of the bidirectional three-terminal thyristor 24, which controls the phase of the load power. Phase control is possible, and when the secondary coil is short-circuited, phase control close to full ignition can be achieved (FIG. 6(e)).In the next half cycle, the polarity is reversed and the same effect is performed. This oscillation is performed synchronously every half cycle of the power supply voltage.

Bidirectional three-terminal thyristor 24 in the circuit shown in Figure 5.
is ignited by the first discharge of the above-mentioned action, the voltage to the control circuit is almost gone (only the voltage drop of the bidirectional three-terminal thyristor 24), so the half voltage as shown in B' and D' in FIG. The effect is the same, but only the first pulse signal per cycle.

In addition, another one is connected in parallel to the switch 13 and the variable resistor 12.
It is convenient to provide a switch that allows you to reach a position close to full ignition (maximum power) from any phase, and if you use a variable resistor as a fixed resistor and select an appropriate resistance value to switch, you can change the power level. remote control is possible by extending the wiring between the secondary coil, switch, and resistor.

Since the present invention has the structure and operation as described above, it has the following features and effects and is extremely useful.

Since a leakage type tripod transformer is used, the operating switch and variable resistor are completely isolated from the power supply, and the circuit voltage is designed to be low, so there is no risk of electric shock.

Phase control of AC power can be performed over a wide range from near full ignition (0 degrees) to nearly 180 degrees, so it can be used not only in consumer equipment but also in industrial equipment, and its applications are extremely wide.

Since the current flowing through the leakage type tripod transformer is extremely small, it can be made compact, and the entire control device can also be made compact, making it inexpensive.

Remote control is possible by extending the wiring to the switch and variable resistor.

Stepwise power control is also possible by replacing the variable resistor with one or more fixed resistors and creating a short-circuit/open structure with another switch.

Since this is a phase control circuit using a leaky tripod transformer with a gap in the third leg, false firing will occur if the signal voltage applied to the gate of the bidirectional three-terminal thyristor is ≈0 when the switch (or variable resistor) is opened. There is no fear.

Instead of using separate input and output transformers as in the past, a leaky tripod transformer is used, so the transformer can be provided in a small, lightweight, and low-cost manner, and as a result, it naturally reduces the load of AC motors in application circuits. The phase control circuit unit can also be manufactured in a small size, light weight, and low cost.

Since a leaky tripod transformer is used, the price of the transformer is 3/4 of that of conventional ones, and the space required for installation is 70%, which is a great benefit for Japan's home appliance industry. It has a very large economic value when considered in terms of production volume, which is several million units per year.

[Brief explanation of drawings]

1 and 2 are circuit diagrams of a conventional example, FIG. 3 is a circuit diagram of an AC power phase control circuit showing an embodiment of the present invention, and FIG. 4 is a gap diagram of a monopod used in the present invention. FIG. 5 is a partial circuit diagram with the connections in the circles in FIG. 3 changed, and FIG. 6 is a waveform diagram of each part for explaining the operation of the embodiment phase control circuit. 1: Leaky tripod transformer, 5: Gap, 6:
Primary coil, 7: Secondary coil, 8: Tertiary coil,
12: Variable resistor, 14, 18: Full wave rectifier, 1
6: Capacitor, 20: Transistor, 24: Bidirectional three-terminal thyristor, 25: SBS.

Claims (1)

[Claims] 1. A leakage type tripod transformer in which one leg of the tripod core has an open end with a gap, and a primary coil connected to an AC power source is wound around one non-open leg, and the other leg has an open end with a gap. A secondary coil is wound around the leg, a tertiary coil is wound around the open leg, a variable resistor and a switch are connected in series to the secondary coil, and the AC power source is connected to the secondary coil.
A series circuit of a first full-wave rectifier, a resistor, and a capacitor is connected in parallel, and both ends of the tertiary coil are connected to a second full-wave rectifier.
The DC side output of the second full wave rectifier is divided between the base and emitter of the transistor connected to the DC side of the first full wave rectifier. An alternating current power phase control circuit using a leaky tripod transformer, characterized in that the coupling point between the capacitor and the load is connected via a trigger element to the gate of a bidirectional three-terminal thyristor connected in series with the load. 2. The device according to claim 1, characterized in that a primary coil, a series circuit of a first full-wave rectifier, a resistor, a capacitor, and a load are connected in parallel to a series circuit of a bidirectional three-terminal thyristor. AC power phase control circuit using a leaky tripod transformer. 3. A primary coil and a series circuit of a first full-wave rectifier, a resistor, and a capacitor are connected in parallel to a bidirectional three-terminal thyristor, and a load is connected between this parallel circuit and an AC power source. An alternating current power phase control circuit using a leaky tripod transformer according to claim 1.