JPS61231615A - Power controller - Google Patents

Abstract

PURPOSE:To attain smooth start and power saving by providing a phase control circuit and phase control adjusting circuit so as to apply a large voltage to a load such as a induction motor at start. CONSTITUTION:When a main power switch 32 is applied, a voltage of a load 38 reaches, e.g., 85V by the voltage drop operation of the phase control circuit 36. The induction motor 48 as a load 38 is not start but a large start current flows. A timer 72 is started by the large start current and a phase control adjusting circuit 70 is operated. Since an output of the circuit 70 decreased the voltage drop by the phase control circuit 36, a full voltage 100V is applied to the motor 48. Thus, the motor 48 is started smoothly. When the timer 72 reaches a set time, the motor 48 is operated at 85V and power is saved.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention enables smooth starting of equipment such as motors and fluorescent lights equipped with a phase control circuit in the power supply system for the purpose of power saving, etc. This invention relates to a power controller that can perform various operations.

"Prior Art" In electrical equipment such as induction motors and fluorescent lights for home or business use, power controllers equipped with phase control circuits are connected for the purpose of power saving, etc. In some cases, the voltage is lowered to 85V and then supplied to the load side.

FIG. 2 shows a conventional example of the above power controller,
A snubber circuit consisting of a capacitor 143 and a resistor 16 is connected in parallel to the thyristor 12 whose phase angle is controlled by the trigger circuit IO, and then connected in series to the reactor 1B, and the voltage on the input side 20 is adjusted to the desired value on the load side 22. It is descending to

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional power controller, for example, 10
When driving a mechanically loaded induction motor that is set for 0V, for example, if a voltage dropped to 85V is applied, there will be a lack of effective power at startup, and a rotation lock phenomenon will occur due to the balance between rotational torque and load torque. There was a problem that the computer would not start up smoothly or would have difficulty starting up.

Also, when lighting a fluorescent lamp that is set for 100V, for example, if a voltage lowered to 80V is applied using a phase control circuit, the filament will not be heated sufficiently at the initial lighting stage, making lighting difficult. There's a problem.

In addition, even when the light is on, the flicker phenomenon tends to occur when the applied voltage is low due to wear and tear of the fluorescent light over time, or the same flicker phenomenon occurs when the line voltage itself on the input side drops for some reason. There was the inconvenience of doing so.

This invention solves the above-mentioned problems such as rotation locking of the electric motor and difficulty in starting, difficulty in initial lighting of the fluorescent light, and occurrence of flicker during lighting, and enables smooth startup of load-side electrical equipment. Another object of the present invention is to provide a power controller that performs power saving and rotation control so as to maintain a reliable operating state.

"Means for Solving the Problems" The configuration of the present invention in accordance with the above-mentioned purpose is to provide a power controller that reduces the voltage by providing a phase control circuit between the input side and the load side. The voltage is detected by a voltage detection circuit, and with this detection signal containing fluctuation components caused by the operation of the load-side electrical equipment, the starting signal is compared with a predetermined reference level by a comparison circuit, and the detection signal is determined as the reference level. The gist of the present invention is that a phase control adjustment circuit receives a signal outputted from a comparison circuit when the voltage drops below the voltage level, and controls the amount of voltage drop to be reduced for a predetermined period of time.

In short, the present invention addresses the fact that when an electric motor, etc. tries to start, a large starting current flows and the line voltage itself on the input side drops. This was done based on the fact that electrical equipment may malfunction when the temperature decreases, and also that noise is generated when fluorescent lights, etc. try to turn on or malfunction. It is possible to suppress the power control that is performed during steady and normal operation when starting (starting) electrical equipment, etc., when it malfunctions, or when there is a risk of malfunction, thereby ensuring smooth startup (starting) of electric motors etc. ) operation and the realization of normal and reliable operating conditions.

``Embodiments'' Next, preferred embodiments of the present invention will be described with reference to the drawings. 9. FIG. 1 is a circuit diagram showing a vending machine according to the present invention.
In the figure, a main circuit is formed by connecting a phase control circuit 3B and a load 38 in series to a plug 30 that receives, for example, a commercial power supply of AC 100V via a main power switch 32 and a fuse 34.

The phase-side W circuit 38 includes a triac 40 inserted into the main circuit and a trigger circuit 42 for turning on the triac 40 at a predetermined phase angle. A phase control adjustment circuit 70 is connected to the trigger circuit 42 for switching the phase angle between two stages: a substantially minimum value and a normal phase angle.

Trigger circuit 42t≠Capacitor Ct with one terminal connected to the T1 side of triac 40, and four diodes DI bridge-connected in a predetermined direction to both ends of C1.
-04, DI and D2. D2 and D3. Resistors R1 to R5 connected between each connection point of 03 and D4 and the T2 side of the triac 40, and the other terminal of C1, that is, the connection point of D2 and D3 and the gate terminal G of the triac 40. It consists of an SBS inserted in between.

This trigger circuit 42 is connected to the Tl side R of the triac 40.
4. Current flows from R2, R3 to at, and in either case, after the polarity changes, the SBS is switched and a negative or positive trigger pulse is applied to the G terminal of the triac 40 after a predetermined charging time determined by C1 & R2 to R4. Apply.

When a trigger pulse is input from the trigger circuit 42, the trier → circuit 40 becomes conductive, and then the conduction state is maintained until the voltage between TI and 72 becomes zero. After the voltage between TI and 72 becomes zero, the trigger pulse is received. This phase angle can be varied by adjusting the variable resistor R3, and in this embodiment, for example, the resistors R2,
The AC1oov voltage (line voltage) input from the plug 30 without short-circuiting both ends of R3 is reduced to 80V and is set to a value that is supplied to the load 38. The phase angle at this time is hereinafter referred to as the normal phase angle.

On the other hand, R4 is much smaller than R2 and R3,
When both ends of the resistors R2 and R3 are short-circuited, the phase angle is set to a minimum phase angle close to zero, and at this time, the input voltage Actoov is applied to the load 38 almost as is. ing.

By changing the value of R4 appropriately, it is also possible to set the phase angle so that the voltage applied to the load is, for example, 90V when both ends of R2 and R3 are short-circuited, instead of the minimum phase angle.

01-114 in the trigger circuit 42. R1 and R5 are for reducing hysteresis.

A choke coil L1 is connected in series in the main circuit on the Tl terminal side of the triac 40, and the choke coil L1
, A capacitor C2 is connected in parallel with the triac 40. These Ll and C2 form a low-pass LC filter, and together with the choke coil L2 connected in series in the main circuit on the T2 terminal side of the triac 40, they are used to suppress high frequency noise generated when the triac 40 is turned on. It is. C3. inserted in parallel to C2. Re is for noise suppression and adjustment to improve turn-on of the triac 40.

On the other hand, there is a C between the TI and T2 terminals of the triac 40.
4, R7 and C5, R8 are connected in parallel. These C4, R7, 05, and R8 are intended to prevent flickering, which tends to occur when a phase-controlled low voltage is input to the fluorescent light 44 with a 3-day load.

To explain in more detail, in general, when a phase-controlled voltage is applied to a fluorescent light load, there is almost no problem if the phase angle is small and the power saving rate is 20% or less, but if the power saving rate is 30%.
When the phase angle exceeds 90°, flicker phenomenon (including flickering at every cycle to flashing at intervals of several seconds) will occur, and when the phase angle exceeds 90°, the light will no longer turn on. Put it away. For this reason, conventionally 20% to 3
It was difficult or impossible to save power by more than 0%.

However, if a small current is applied to the fluorescent light even when the triac is not conducting (of course at a level that does not significantly impair the power saving effect), the phase angle can be increased to 9 without causing flicker.
The inventor has discovered that phase control of 0° or more is possible.

A method of passing a small current through the fluorescent light when the triac is not conducting is to install a bypass circuit in parallel to the triac in the main circuit, and turn on the bypass circuit to allow current to flow only when the triac is not conducting. Alternatively, the bypass circuit is always on so that current flows through the bypass circuit even when the torch is not conducting and when the torch is conducting (however, when the torch is conducting, the voltage across both ends is almost zero).

The former can be composed of, for example, thyristor elements, R, C, and L, which are controlled in phase opposite to the triac. The latter can be composed of R, C, L, etc.

Further, a pulse generator or the like may be connected to both ends of the fluorescent light to cause a small current to flow through the fluorescent light when the torch is not conducting. In short, it is sufficient that the phase control circuit is a small current supply circuit that can cause a small current to flow through the fluorescent lamp when the phase control circuit is not conducting.

Specifically, a small current flowing in a bypass circuit with only a resistor is fine, but it has the disadvantage of causing heat loss in the resistor, so C
If the constant is set appropriately in combination with R so that the small current has a peak during the non-conducting period of the torch, the small current itself can be made small, and it can be applied over a wider range of phase angles. , multiple fluorescent light loads are installed in parallel, and flicker can be reliably prevented even if there is a fluorescent light load that is far away from the plug (which is more unstable than one closer to the plug due to line loss, etc.). It has this excellent effect. FIG. 9 shows a pattern of fluorescent light current including small currents. (1) is a resistor-only bypass, and (2) is a waveform with peaks at C and R.

It goes without saying that the method of making the small current have a peak may be other than the combination of C and R.

Furthermore, if a pulse generator is used, a single pulse may be generated within a non-conducting angle, for example.

In this way, it is possible to save power by more than 80%.

In this embodiment, for example, when five 100V 30-volt fluorescent lights are used, for example, C4=O, l Jj-lower.

R? = 100Ω, C3=L4 ILF, R8=
The resistance should be approximately 50Ω. G4. R7, C5, and R8 also have a function as a snubber circuit as a whole. Also, 05
．． Even if a disconnection accident occurs on the R8 side, 04.
Since R7 is set to the same constant as the conventional snubber circuit, the turn-on operation of the triac 40 can be maintained in a good condition.

The load 38 includes an induction motor 48 connected to a compressor 4B for cooling products (canned juice, packaged milk, etc.), a fluorescent light 44, a product supply mechanism (coin mech) 50, a microcomputer system 52 for banknote identification, etc. electrical devices are connected in parallel.

Induction motor48. Fluorescent light 44. The product supply mechanism 50 includes relay switches 54 and 5 for turning on power individually.
6.58 is provided. The relay switch 54 is linked to a thermostat (not shown) that operates by detecting the product temperature, and when the product temperature exceeds a predetermined value, the relay switch 54 closes at the same time as the thermostat closes, and conversely, the product temperature reaches the predetermined value. When the temperature falls below, the thermostat opens and the relay switch 54 also opens at the same time.

The induction motor 48 has a constant rotation characteristic with little change in rotation speed even if the applied voltage changes, and the compressor 4B
has a constant load torque characteristic in which the load torque is almost constant even if the rotational speed changes. Normally, the applied voltage of the 100V induction motor 948 for driving the compressor 46 is approximately 85 to 80V.
Normal operation is possible even at an operating point of about V, and even if the applied voltage increases, there is little change in the rotational speed and the cooling capacity hardly changes. Therefore, power can be saved by the voltage drop from 1 OOV.

However, the starting torque of the induction motor 48 is small, and on the contrary, the starting load torque of the compressor 48, such as a reciprocating type, is large. Therefore, when the relay switch 54 closes to start the motor, the voltage applied to the induction motor 48 is 8.
If the voltage is 5V, the effective power will be insufficient and a rotation lock phenomenon will occur due to the balance between rotational torque and load torque, and there is a possibility that the motor will not start smoothly or will be difficult to start.

In this embodiment, when the induction motor 48 tries to start with the compressor 46, which is a mechanical load, connected, a large starting current (more than several times that of steady operation) flows, and the voltage of the commercial power line increases. Since this causes a large fluctuation in the value, this is used to prevent starting failure of the induction motor 9.48. - Note that noise components generated when the starting current is generated may be used.

The relay switch 56 is linked to a timer (not shown), and is closed from 5pm to 7am when it is dark outside, and conversely opened from 7am to 5pm. ing.

Fluorescent light (4 is for illuminating the product sample to make it easier for users to see the product, etc.) If the applied voltage is set to 85V with phase control compared to 100V, a large power saving rate of about 50% can be obtained. .

However, as in the case of the induction motor 48, if the voltage applied to the fluorescent lamp 44 is low at the time of initial lighting when the relay switch 5B is closed, the filament will not be heated sufficiently, making lighting difficult. In addition, even after the light is turned on, the discharge operation tends to become unstable if the applied voltage is a low phase-controlled voltage, especially if there is deterioration over time or if the line voltage of the commercial power supply itself is low in the evening. Flicker phenomenon may occur when household power consumption increases and then decreases.゛ - In this embodiment, the initial lighting failure and flicker phenomenon are prevented by utilizing the noise component and line voltage drop that occur when the fluorescent light 44 initially lights up or when a flicker phenomenon occurs. I have to.

The relay switch 58 is interlocked with a product selection switch (not shown), and when the product selection switch is pressed, the product supply mechanism 50 is activated to drop the product into the outlet of the vending machine, for example, while rotating the product. It has become.

The product supply mechanism 50 is composed of an electric motor, a solenoid, or the like, and normally, if the applied voltage is maintained at 85 V or higher, the product can be dropped into the outlet.

However, if the vending machine is installed in a poor environment and is not maintained properly, dirt and dust will accumulate inside the machine, making the feeding mechanism 50 difficult to operate, especially in the case of heavy products such as 11 cans and 1-stand packs.

If the applied voltage is low, the driving force will be insufficient, which may result in jamming.

In this embodiment, a noise component generated by a transient current flowing when a voltage is applied to the product supply mechanism 50 is used to prevent product supply defects.

Since the microcomputer system 52 is always in operation, no relay switch or the like is provided. Since the banknote identification device operated by the microcomputer system 52 performs subtle detection, it may malfunction if steep noises generated when the triac 40 is turned on and off are introduced.

In this example, as described above, Ll, C2,03, R8
Further, L2 is added to the LC filter according to the above to prevent malfunction of the microcomputer system 52.

Note that noise filters may be inserted at the positions indicated by dotted lines A and H for the load such as the microcomputer system 52.

A transformer 80 is connected to the load side of the fuse 34 in parallel to the main circuit. This transformer 60 has a primary input A
A bridge circuit 62 that converts C100V into a secondary output AC12V and is composed of four diodes D5 to D8 connected to the secondary side, a resistor R8, a large capacitor C6, a bleeder resistor RIO, and a light emitting diode D9 for indicating power ON. , resistor R11, and Zener diode zD together with A
A stable DC voltage E of 9V (ZD Zener voltage) is obtained from ClooV.

The transformer 60 and the bridge circuit 62 also have a function as a power supply voltage detection circuit. That is, although the output terminal voltage BE of the bridge circuit 62 is pulsating, AClooV
When the line voltage changes, BE also changes approximately in proportion to it. This BE is outputted to the level conversion circuit 64 as a power supply voltage detection signal. Note that even if the line voltage decreases to some extent, E hardly changes.

This level conversion circuit 84 connects the DC voltage E with a resistor R12,
It consists of a transistor Tr whose collector is connected through R13 and whose emitter is connected to ground through a resistor R14. The output terminal voltage BE of the bridge circuit 62 is connected to the resistor R.
15 to the base of the Tr.

Therefore, the emitter output E of the Tr. will change in proportion to BH. This output voltage E. The size of can be adjusted to an appropriate value by changing the variable resistor R13.

Output voltage E. When the line voltage decreases due to an increase in power consumption in a typical household, the voltage level decreases accordingly. Furthermore, when the line voltage transiently decreases due to a large starting current flowing when the induction motor 48 starts up, the voltage level fluctuates downward.

Further, when the fluorescent light 44 is initially turned on or when flickering occurs, noise components generated due to current changes when the product supply mechanism 50 is started enters the Tr mainly through the base circuit of the Tr, and is amplified in the output voltage E. . It will be superimposed on

Tr emitter output E. is applied to the trigger terminal TR of the timer circuit 72. In the timer circuit 72, a power terminal Vf is connected to a DC voltage E, and a terminal V- is connected to ground. Reset terminal R is connected to E. In addition, the threshold terminal TH is connected to ground via a capacitor C7, and a resistor R18
- Connected to E via RI8. T) I is also connected to the discharge terminal DC. RlB, R1
? can be selected by a changeover switch 74, of which R17 is a variable resistor.

RIB to R1B and C7 are for setting one hour of the timer circuit 72, for example, the changeover switch 74.
When turned to the RIEI side, the time can be set to about SO5, and when turned to the R17 side, the time can be set to about 78.

The latter 78 is sufficient time to start the induction motor 48, the fluorescent light 44, and the product supply mechanism 50.

The control voltage terminal Cv of the timer circuit 72 is connected to ground via a capacitor C8 to prevent malfunction. The timer circuit 72 configured in this manner operates as follows. That is, the DC terminal and output terminal OUT are set to "low" in advance.
level and C7 is in a fully discharged state, the input level of the Tr terminal is 1/3 or less of the applied voltage between v+ and V- (this is called trigger threshold VTR)
When the voltage falls to , a timer start operation is performed to open the DC terminal and simultaneously set the output terminal OUT to a "high" level.

Then, over time, RlB, RIB or R1
Charging of C7 progresses through C? The + side voltage of
When the applied voltage between +--■- reaches 2/3 or more, a time-up occurs, and the DC terminal is set to a "low" level, and at the same time, the output terminal OUT is set to a "low" level.

Tr emitter output E with respect to trigger threshold VTR.

The level of the timer circuit 72 is set to be higher by a predetermined amount under normal operating conditions (see (A) in Figure 3).The OUT terminal of the timer circuit 72 is connected to the phase control adjustment circuit ?0. The control adjustment circuit 70 is connected to the trigger circuit 4.
2 connected in parallel R2. Four diodes Dlθ~013 bridge-connected to both ends of R3, an SCR inserted between the connection point of 010 and Dll and the connection point of 012 and 013, and a gate circuit 74 for applying a gate voltage to this SCH. It is composed of.

The gate circuit 74 consists of a resistor R19 connected in series between E and ground, a light emitting diode 014 for indicating when the adjustment circuit is in operation, and resistors R20 and R21. The OUT terminal of the timer circuit 72 is connected between R19 and 014. Further, both ends of R21 are connected to the gate terminal and cathode terminal of the SCR.

When the timer circuit 72 is at the "low" level, 014 is not lit and the voltage across R21 is almost zero, so the SCR becomes non-conductive and the phase control adjustment circuit 70 is disconnected from the trigger circuit 42. It is separated and has no effect. At this time, the triac 40 is normally controlled by the phase angle.

Conversely, when the qUT terminal of the timer circuit 72 is at the high level, D14 lights up and a voltage is generated across R21, making it non-conductive. At this time, R2 and R3 of the trigger circuit 42 are short-circuited through nto~013, and the trier -/1 40 is controlled at the minimum phase angle.

"Operation" Next, the operation of this embodiment configured as described above is explained by the conceptual principle explanatory diagram in Fig. 3 ((B) to (F) in the figure show noise only in the negative direction). I will explain with reference. still,
It is assumed that the plug 39 is connected to a commercial power source and the main power switch 32 is turned on in advance. Also, since the power is turned on, the microcomputer system 52
Since a current flows through the switch, it is assumed that the switch 40 normally controls the phase of the voltage using the phase angle. Therefore, the voltage 9 on the load 38 side is 85V.・
First, when the temperature of the product rises and the thermostat operates and the relay switch 54 closes, the induction motor 48
A voltage of V is applied. The induction motor 48 is urged by the applied voltage and tries to start, but it does not start immediately because the compressor 48, which is a mechanical load, is connected.
At this time, a large starting current flows.

This starting current affects the commercial power supply side, and the line voltage transiently decreases and fluctuates due to the internal voltage drop. This decrease fluctuation in line voltage is detected by the transformer 80 and the bridge circuit 62, and is input to the TR terminal of the timer circuit 72 as a fluctuation in the emitter output E of the Tr.

, due to the large drop fluctuation in Eo, it falls below the trigger threshold VTR of the timer circuit 72, and the timer starts (see Figure 3 (B)). At the same time as the timer starts, R2 and R3 in the trigger circuit 42 are short-circuited. Ru.

Therefore, the trigger 40 performs phase control with the minimum phase angle, and a total voltage of approximately 100V is applied to the load 3B.

Therefore, when the induction motor 48 is started, a voltage of 100V, which is sufficient for a smooth starting operation, is applied, and the induction motor 48 is started smoothly. For example, 7 is set in advance by the timer circuit 72.
S (Induction motor reaches normal rotation in 2 to 3 seconds on 4th day)
When time has elapsed, the triac 40 returns to the normal phase angle control state for power saving.

After that, the induction motor 48 is operated at 85V to save power. The induction motor 48 is operated until the product reaches a predetermined temperature and the thermostat opens.

Next, when the product selection switch is pressed by the user, the relay switch 58 closes and the product supply mechanism 50 attempts to start up. At this time, the current flowing through the main circuit suddenly increases, causing large spike noises in the main circuit and the transformer 60.
．． T passes through the bridge circuit 62 and enters the base circuit.
The emitter output E of r. It appears in This E. E due to the noise component on the. is lower than the instantaneous trigger threshold VTR, so the timer starts (see FIG. 3(C)), and in the same way as described above, the voltage applied to the product supply mechanism 50 is set to 100.
Since the voltage is the full voltage of v, the product can be reliably fed without causing the product to get caught.

Time-up occurs after sufficient time has elapsed for the operation of the product supply mechanism 50 to be completed.

Further, when the time reaches 5:00 in the evening and the timer is activated and the relay switch 56 is closed, a voltage of 85V is applied to the fluorescent light 44. The fluorescent lamp 44 starts discharging when a voltage is applied for a moment and attempts to initially light up. When this relay switch 58 closes and a discharge start operation occurs, a large switching and discharge noise is generated, which enters the base circuit of the Tr by induction or wrap around from the ground, and emitter output E.
. appears in

This E. The noise component (fluctuation component) superimposed on the E.

Since VTR is below the instantaneous trigger threshold VTR, the timer starts (see Figure 3 (D)), and in the same manner as described above, the voltage applied to the fluorescent lamp 44 becomes the full voltage of 100V, and the filament is sufficiently heated. To surely turn on the light without causing initial lighting failure.

Next, the timer circuit 72 presets 7 seconds (fluorescent light 4).
4 (sufficient time to complete lighting), the triac 40 returns to normal phase angle control. Therefore, after that, the fluorescent light 44 continues to be lit at 85V, resulting in significant power savings. The fluorescent light 44 is turned on until the timer operates at 7 o'clock in the morning after dawn and the relay switch 5B is opened.

Separately, as a result of deterioration of the fluorescent lamp 44 over time, the applied voltage is as low as 85V while the lamp is on, causing unstable discharge and flickering, which also causes extremely large noise. However, the voltage falls below the inductive value VTR (see (E) in FIG. 3), so that the voltage applied to the fluorescent lamp 44 during lighting becomes toov, resulting in a stable lighting state.

This total voltage application of 100V ends in 7 seconds, and if no flicker phenomenon occurs thereafter, the original voltage application state of 85V returns. If the flicker phenomenon tends to recur when the applied voltage reaches 85V, the full voltage is immediately applied again when the flicker phenomenon occurs, so the occurrence of flicker can be suppressed as much as possible in terms of time. This can significantly reduce the discomfort experienced by the user. Further, if the flicker phenomenon continues, power consumption increases, but this can also be suppressed. If the flicker phenomenon always occurs with an applied voltage of 85 V, it is preferable to lengthen the flicker occurrence period by turning the selector switch 74 of the timer circuit 72 to the R1B side to make the total voltage application time 8Qs.

Next, when a voltage drop occurs on the commercial power supply side due to an increase in electricity demand in general households in the evening and the line voltage AC100V itself drops, the DC voltage E is kept constant at ZD, but the output terminal of the bridge circuit 82 Voltage BE decreases.

In response to this decrease in BF-, the emitter output E of the Tr. also decreases.

And this E. The overall level of V
When approaching TR, even if the fluctuation component included in Eo is small, it momentarily falls below VTR.

This is equivalent to increased sensitivity to the fluctuation component of Eo. This increase in sensitivity is useful for preventing the lighting of the fluorescent lamp 44 from becoming unstable due to a drop in load applied voltage due to a drop in line voltage.

In other words, the lighting of the fluorescent light 44 may begin to become unstable due to a drop in the applied voltage, and at this time, even if the flicker phenomenon has not yet occurred, a noise component that is slightly higher in level than when the lighting is normal is generated. do. This is due to the flicker phenomenon, but the level of the noise component is lower than that due to the drop in line voltage. In response to a decline in the overall level of E. lower than the VTR and start the timer (see Figure 3 (F)).

As a result, the voltage applied to the load 38 side becomes the full voltage (however, it is lower than 100V because the line voltage has decreased), and it is possible to prevent a flicker phenomenon from occurring due to a lighting failure of the fluorescent light 44. I can do it.

As the line voltage decreases further, the overall level of Eo decreases further and finally falls below the VTR (3rd level).
(See Figure (G)), at this time the timer starts. As a result, the applied voltage on the load 38 side becomes the full voltage, and when the fluorescent light 44 is on, it is possible to prevent lighting failure or lighting stoppage due to an extreme drop in the applied voltage. .

Furthermore, when the induction motor 48 is in operation, cooling the product takes a long time due to a drop in cooling capacity due to an extreme drop in applied voltage. This can be prevented.

In addition, the timer circuit 72 is configured to immediately restart the timer if Eo is still below the VTR after a time-up of 7S after the start, and the above-mentioned phase control of all voltages is continued. Ru. At around 5 o'clock in the evening, when the line voltage regularly decreases every day, the selector switch 74 may be switched to the RIEI side to extend the timer to 80g for one hour.

According to the above embodiment, when starting up the induction motor, fluorescent light, product supply mechanism, etc. on the load side, a full voltage that lasts for an arbitrary predetermined period of time is applied, so that a smooth starting operation can be performed quickly.
It can be carried out reliably, and even if the line voltage drops during operation, it will maintain proper and stable operating conditions.
A reliable operating state can be maintained reliably. .

In the above embodiment, the DC voltage E is obtained as much as the power of the commercial power supply, but a battery may be used to make the timer and circuit resistant to noise. In addition, the method for detecting the power supply voltage is as shown in Fig. 4. 1. Two sets of secondary windings of the transformer 7. A DC voltage E is uniformly obtained as shown in FIG. ', may be applied to the base of the first Tr with or without a predetermined resistor, or may be directly input to the TR terminal of the timer circuit 72. ,
In the latter case, one of R30 and R31 may be made variable to adjust the detection voltage level with respect to the trigger threshold VTR. Noise caused by the operation of load-side electrical equipment, such as the start-up of load-side electrical equipment or the flicker of fluorescent lights, is contained in the resistor R30.

It may enter the loop formed by the 4 lines connecting the point between R31 and the Tr or TR terminal and the ground board by induction, or it may go around the trigger circuit, circuit 42, or Mi, through the ground board, etc., to the detection voltage. Superimpose. Therefore, as in the case of FIG. 1, the structure is simple because there is no need to provide a special circuit for superimposing the noise component on the detection voltage. However, it is also possible to superimpose a simple configuration such as providing a capacitor for high frequency passage between the main path and the base side of the Tr or the TR terminal side. Furthermore, the amount of superimposition can be increased by connecting a high frequency passing capacitor GO in parallel to R15 in FIG.

In addition, in the above embodiment, the phase control state of 85V was returned to full power pressure, but if the start-up of the load-side electrical equipment, etc. is good, it may be about 80V. The way to return it to V can be easily adjusted by adjusting the setting value of R4 in FIG. The configuration of the phase control circuit is not limited to that shown in FIG. 1, and for example, as shown in FIG. 5, the trigger circuit 80 may include a well-known starting compensation circuit 92.
In the case of the diagram, starting compensation, diomide bridge 8 of circuit 82
A switch 8B such as a relay, a switch, or a thyristor switch is provided on both ends of the capacitor C in 4,
For example, the switch 8B is controlled depending on whether or not there is a voltage across R2,1 in FIG. At this time, the change in the effective value of the load applied voltage after the timer starts is shown in (1) of FIG. 6, and the change in the case of FIG. 1 is shown in (2). Note that when the drop in line voltage due to increased power consumption in a general household is small, the circuit configuration after the Tr in FIG. (corresponding to the VTR in FIG. 1), the switch 96 in FIG. 5 may be turned on by a signal output from the comparator circuit 100.

Furthermore, as shown in FIG. 8, the phase control adjustment circuit 70 of FIG.
Then, the entire phase control circuit 3B may be short-circuited after the timer starts. Also, instead of triac, S
It goes without saying that the phase control circuit may be constructed using other thyristors such as CR and GTO.

Moreover, the number of load-side electric devices may be one.

"Effects of the Invention" As described above, according to the present invention, with an extremely simple configuration,
When there is only one electrical device on the load side, a large voltage can be applied at startup to ensure smooth startup, and during operation, the voltage can be maintained at the desired voltage to save power. When this happens, a large voltage can be applied to ensure reliable operation.

Additionally, when there are multiple electrical devices on the load side, it is possible to apply a large voltage to each electrical device when starting it up to ensure smooth startup, while maintaining it at the desired voltage during operation to save power. In addition, it is also possible to cause the equipment to start up smoothly and to maintain reliable operation regardless of a drop in line voltage.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a vending machine according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a conventional power controller, FIG. 3 is an explanatory diagram of the operation of FIG. 1, and FIG. The figure is a circuit diagram showing another example of the power supply voltage detection method, Figure 5 is a circuit diagram showing another example of the phase control circuit, and Figure 6 is an explanation showing a comparison of the operations in Figures 1 and 5. Fig. 7 is a circuit diagram showing a partial modification of Fig. 1, Fig. 8 is a circuit diagram showing another embodiment, and Fig. 9 is an overall flow to the fluorescent light due to the provision of a bypass circuit. FIG. 2 is a diagram schematically showing a typical current waveform. In the figure, 36... Phase control circuit, 38... Load, 80... Transformer, 62... Bridge circuit, 70... Phase control adjustment circuit, 72... Timer.

Claims (2)

[Claims] (1) A phase control circuit that drops the voltage between the power supply and the load-side electrical equipment, and a voltage detection circuit that detects the power supply voltage;
A comparison circuit that compares the detection signal output by this voltage detection circuit with a predetermined reference level in a state that includes fluctuation components caused by the operation of the load-side electrical equipment, and a comparison circuit when the detection signal falls below the reference level. 1. A power controller comprising: a phase control adjustment circuit that controls the amount of voltage drop caused by the phase control circuit to be reduced for a predetermined period of time based on a signal output from the phase control circuit. (2) The power controller according to claim 1, wherein the load-side electrical equipment comprises a plurality of electrical equipment installed in parallel.