JPS59221718A - Phase control circuit of alternating current electric power using tripod transformer - Google Patents

Abstract

PURPOSE:To eliminate an electric shock accident and at the same time to attain miniaturization of the titled control circuit, by using a tripod transformer to insulate an operation switch and a variable resistor from a power supply. CONSTITUTION:A variable resistor 12 and a switch 13 are connected in series to both terminals of a secondary coil 7 of a tripod transformer 1. At the same time, a primary coil 6 and a series circuit of a full wave rectifier 14, a resistance 15 and a capacitor 16 are connected in parallel to a power supply 17. While a full wave rectifier 18 is connected to both terminals of a third coil 8. A capacitor 19 for pulse absorption is put into the DC side of the rectifier 18, and the DC output is divided and applied between the base and the emitter of a transistor 20 connected to the DC side of the rectifier 14 via resistances 21 and 22. Then the juncture of the resistance 15 and the capacitor 16 is connected via an SBS25 to the gate of a triac 24 which is set in series to a load 23 connected to the power supply 17. The charging time of the capacitor 16 is delayed by varying the resistor 12. Thus the phase control is made possible for the load electric power.

Description

Detailed Description of the Invention The present invention uses a tripod transformer to insulate the power supply and the operation circuit, and also generates an electromotive force in the 98th coil by controlling the secondary coil to control the phase of the triac and generate AC power. This relates to a circuit that controls the

Conventionally, all alternating current power control circuits using scR, Liasoc, etc. were directly connected to an alternating current power source as shown in FIG. 1, so there was a risk of electric shock during power control. 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. Because I can't
When controlling the phase, a separate control circuit is required, making it even more expensive.

In order to solve these conventional drawbacks, the present invention uses a tripod transformer to insulate the operation switch and the power supply, and changes the resistance connected to the secondary coil and shorts and opens the switch.
It adjusts the electromotive force of the tertiary coil or makes it zero, controls the oscillation of the oscillation circuit consisting of a resistor, capacitor, and trigger element SBB, controls the phase of the triac, and controls the power of the load connected in series with it. .

In explaining the present invention in detail, the structure of the tripod transformer will first be described. There are two types of tripod transformers with tripod cores, as shown in Figures 4 and 5.
The tripod transformer 1 in Fig. 4 has outer legs 2 and 4 on the tripod core.
It has a central leg 3 and an outer leg 4 with a gap 5. A primary coil 6 is wound around the outer leg 2, and the central leg 3
A secondary coil 7 is wound on the outer leg 4, and an octagonal coil 8 is wound on the outer leg 4 with the other gap 5 so that a low voltage is induced. The tripod transformer 1 in Fig. 5 has two inner iron cores 9.
．． 10 are isolated and coupled with a non-magnetic material 11 to form a tripod iron core, with a primary coil 6 on the outer leg 2 and a wide central leg 3.
The structure of the tripod core is different from that shown in FIG. 4 in that the secondary coil 7 is wound around the outer leg 4, and the 8th coil 8 is wound around the other outer leg 4.

FIG. 3 shows a circuit according to an embodiment of the present invention, which uses the above-mentioned tripod transformer 1, and has a variable resistor 12 connected to both ends of the secondary coil 70.
and the switch 13 are connected in series, the series circuit of the primary coil 6, full-wave rectifier 14, resistor 15, and capacitor 16 is connected in parallel to the power supply 17, and the full-wave rectifier 18 is connected to both ends of the tertiary coil 8. , a DC output from which a pulse absorbing capacitor 19 is inserted on the DC side is divided between the base and emitter of the transistor 2o connected to the DC side of the full-wave rectifier 14 using resistors 21 and 22, and the voltage is divided and applied. The connection point between the resistor 15 and the capacitor 16 is connected to the load 23 connected to the power supply 17, and the trier is connected in series to the gate of the triator 24.
A capacitor 26 and a resistor 27 are connected to each other through a triac protection circuit. Figure 6 is the 8th
In the figure, a primary coil 6, a full-wave rectifier 14, a resistor 15,
The circuit connects the connection point C of the series circuit of the capacitor 16 to the connection point B of the load 28 and the triac 24, and the rest is the 8th circuit.
Same as figure.

First, the characteristics of the tripod transformer 1 will be explained, and then the operation of the circuit of the present invention 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, the primary magnetic flux ψ is the majority of the magnetic flux ψ1' as shown by the solid line.
passes through the center leg 3 and interlinks with the secondary coil 7, inducing a low voltage.However, since a small amount of leakage magnetic flux ψr does not pass through the outer leg 4 with the gap 5, very little leakage magnetic flux ψr passes through the 8th coil 8. No voltage is generated. However, when the secondary coil 7 is short-circuited with the switch 1a', a short-circuit current flows, and a secondary magnetic flux ψ in the opposite direction to the magnetic flux ψf is generated, and the magnetic flux V' on the outer leg 4 side and the magnetic flux ψ on the outer leg 2 side are separated. As shown by the dotted line, the composite magnetic flux of the magnetic flux increased by the short circuit and the magnetic flux ψf' passes through the outer leg 4 with the gap 5, so it interlinks with the 8th coil 8 and is 360 degrees weaker than the power supply voltage. A delayed voltage is generated. That is, this 8th voltage is regarded as a voltage (thin line in FIG. 7A) that is slightly more advanced than the power supply voltage (bold line in FIG. 7A). In addition, in the inner iron composite type tripod transformer 1 shown in FIG.
A low voltage is induced in the secondary coil 7, but since almost no leakage magnetic flux passes through the outer legs 4 of the inner iron core 10, the 8th coil 8
No voltage is generated. However, when the secondary coil 7 is short-circuited with the switch 18', a short-circuit current flows, and a secondary magnetic flux ψ in the opposite direction to the primary magnetic flux ψ is generated. As most of the magnetic circuit is linked to the tertiary coil 8 to form a magnetic circuit, a low voltage that lags the power supply voltage by a little less than 360 degrees is generated. In other words, this voltage is considered to be slightly more advanced than the power supply voltage. Both the tripod transformers in FIGS. 4 and 5 have a voltage that lags the tertiary coil 8 by a little less than 860 degrees in response to a short circuit in the secondary coil 7, that is, 11t.
It is considered to be approximately in phase with @, and has the characteristic of being induced by a slightly leading voltage. 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 8th voltage will decrease accordingly. can be controlled. The operation of the circuit of the present invention utilizing this characteristic will be explained with reference to the circuit of FIG. 8 of the embodiment.

When the switch 18 is open, no voltage is generated in the 8th 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 5BS 25 and triac 24 do not operate. However, when the switch 18 is closed and the variable resistor 12 is 0 ohm, for example, the secondary coil 7 is short-circuited, a voltage is generated in the 8th coil 8, and the voltage rectified by the rectifier 18 is applied to the transistor 200. The voltage is applied between the base and the emitter, and the transistor 2o is completely conductive.The internal resistance is very small υ, and an AC voltage is applied to the capacitor 16 through the combined resistance with the resistor 15, which charges it and breaks the 5B825. When the overvoltage is exceeded, discharge occurs through the gate G of the triac 24 and the terminal TI. This action is repeated, resulting in an oscillation state. The charging and discharging performed every half cycle is determined by the combined resistance of the internal resistance of the transistor 20 and the resistor 15, but in experiments, the number of oscillations was about 10 or less times.

The voltage waveform between the gate G1 terminal 71 of the triac is the seventh
It will look like Figure 1. 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 the internal resistance between the collector and emitter gradually increases. resistance 1
The combined resistance value with 5 increases, and the number of oscillations during a half cycle decreases, reaching a limit of 0. There are times when the voltage waveform between the gate G1 terminal 71 of the triac is as shown in FIG. 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 triac 24, which is controlled in phase, and the load power can be controlled in phase. When the secondary coil is short-circuited, phase control close to full ignition can be achieved (FIG. 7(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.

In the circuit of Fig. 6, when the triac 24 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 triac 24), so as shown in Fig. 7 B' and 2', The effect is the same, but only the first pulse signal per cycle.

If another switch is installed in parallel with switch 13 and variable resistor 12, it will be possible to reach a position close to full ignition from any phase (
It is convenient because the variable resistor can be used as a fixed resistor and the appropriate resistance value can be selected and switched to enable stepwise control of the power.
Remote control is possible by extending the wiring between the resistor and the resistor.

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

(1) Since a tripod transformer is used, the operation switch is difficult.

H. The variable resistor is completely isolated from the power supply and the circuit voltage is designed to be low, so there is no risk of electric shock.

(2) Since the phase control of AC power can be performed over a wide range from near full ignition (0 degrees) to near 180 degrees, it can be applied not only to consumer equipment but also to industrial equipment, and its applications are extremely wide.

(3) Since the current flowing through the tripod transformer is extremely small,
Since it can be made small and the entire control device can be made compact, it is inexpensive.

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

(5) 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.

[Brief explanation of the drawing]

Figures 1 and 2 are circuit diagrams of a conventional example, Figure 3 is a circuit diagram of an embodiment of the present invention, Figure 4 is a block diagram of a tripod transformer with a gap in the monopod used in the present invention, and Figure 5. Figure 6 is a partial circuit diagram with the connections in the circles in Figure 3 changed, and Figure 7 is a voltage waveform diagram.
A is the power supply voltage (thick line) and the 8th voltage (thin line, at the time of secondary short circuit)
Relationship waveform diagram with ``G'' and ``G'' are pulse voltages applied to the gate of the triac (an example when inserting a variable resistor); This is a waveform diagram of the load voltage when the voltage is applied between the triac G-T, and E is 2 and 2'. 1...Tripod transformer 5...Gap 6-・Primary coil 7...Secondary coil 8・
... 8th coil 11 ... Non-magnetic material 12.
-...-Variable resistor 14.18... Full wave rectifier 16... Capacitor 20...
...Transistor 24...Triac 2
5... SBS patent applicant Yasu Electric Co., Ltd. Figure 1

Claims (4)

[Claims] (1) A secondary coil is wound around the central leg of the tripod core, and a variable resistor and a switch are connected in series.A primary coil is wound around one of the outer legs, and a full-wave rectifier, resistor, and capacitor are connected in series. It is connected in parallel to the power supply together with the circuit, and a tertiary coil is wound around the other outer leg to rectify the output and divide the voltage between the base and emitter of the transistor connected to the DC side of the full-wave rectifier. A phase control circuit for AC power using a tripod transformer, characterized in that a connection point between the resistor and the capacitor is connected to a gate of a triac connected in series with a load via a trigger element. (2) An alternating current power phase control circuit using a tripod transformer according to claim 1, characterized in that a tertiary coil is wound with a gap provided in one of the outer legs of the tripod iron ICr. (3) A tripod transformer according to claim 1, characterized in that a secondary coil is wound around the central leg of a tripod core which is isolated and coupled with a non-magnetic material between the legs of two inner iron cores. The AC power phase control circuit used. (4) AC power phase using a tripod transformer according to claim 2 or 8, characterized in that a series circuit of a primary coil, a full-wave rectifier, a resistor, and a capacitor is connected in parallel to a triac. control circuit