JP4398680B2 - Power-saving power supply - Google Patents

Description

  The present invention relates to an electric device configured to be able to be remotely operated such as a television receiver, a video device, an audio device, etc., an electric device configured to provide a sub switch and switch between a standby mode and an operation mode, and a telephone , Facsimile devices, personal computers, etc., electrical devices that need to be always in standby mode when not in use, or electrical devices configured to obtain drive power using an AC adapter such as a modem, a printer, or the like The present invention relates to a technique that can be suitably used for a power supply device.

As a similar technique, there is Japanese Patent No. 3196157 by the present inventor, another Japanese Patent Application Laid-Open No. 2001-78446, and Japanese Patent Application Laid-Open No. 2001-352501. In either case, standby power is reduced by causing a transformer operating at a commercial frequency to operate intermittently or continuously according to circumstances.

Common to the above is that standby power is reduced by using a reactive current flowing through a capacitor to drive the control circuit. In Japanese Patent Laid-Open No. 2001-78446 that places importance on efficiency, it is actively turned on / off at a phase of 90 degrees. Japanese Patent No. 3196157 dislikes noise, and actively operates at a voltage zero point or a current zero point, such as on at a voltage of 0 and off at a point of zero current.
Patent No. 3196157 JP 2001-78446 A JP 2001-352501 A

  However, according to subsequent studies, the power consumption at no load is almost good even in the conventional patent No. 3196157. However, the problem is that the efficiency decreases when an intermediate current value is passed through the load.As a result of examining the phase timing of the current flowing through the transformer as a cause of this, it is not the zero cross but it is more It has been found that the efficiency in current is improved. That is, the zero cross point is preferable for noise generation due to switching timing, but the efficiency at the intermediate current value is preferably around 90 degrees. Nearly 45 degrees, which is a compromise between noise and efficiency, was the most preferable balance point in reality. As described above, a capacitor acting as a reactance dropper, which is a component common to the three applications, is an adverse effect when trying to manage on / off at around 45 degrees, which is preferable as a compromise. As a harmful effect of the capacitor, a phase delay occurs, and the on-phase tends to be longer than 360 degrees. This makes it easy to leave residual magnetism in the transformer, and due to the nature of the transformer, it increases the inrush current when it is turned on at the next timing and tends to cause a decrease in efficiency, so a means to prevent this decrease in efficiency is necessary. It becomes.

  In order to achieve the above object, a power-saving power supply device according to claim 1 is a first power source for rectifying a commercial power supply, a transformer having at least a primary winding and a secondary winding, and an output of the secondary winding of the transformer. A bidirectional switching circuit that opens and closes a current flowing from the commercial power source to the primary winding of the transformer, and an on time of the switching circuit is one cycle of the voltage waveform of the commercial power source or an integral multiple thereof. And a control circuit that controls the on / off of the switching circuit at substantially the same phase difference timing with respect to the voltage waveform of the commercial power source, and is arranged from the commercial power source via an impedance circuit. In the power-saving power supply apparatus in which the rectifier circuit supplies power to the control circuit, the impedance circuit is substantially a resistor at the frequency of the commercial power supply.

  In order to achieve the above object, a power-saving power supply device according to claim 2 is a first power source for rectifying a commercial power supply, a transformer having at least a primary winding and a secondary winding, and an output of the secondary winding of the transformer. A bidirectional switching circuit that opens and closes a current flowing from the commercial power source to the primary winding of the transformer, and an on time of the switching circuit is one cycle of the voltage waveform of the commercial power source or an integral multiple thereof. And a control circuit that controls the on / off of the switching circuit at a timing with substantially the same phase difference with respect to the voltage waveform of the commercial power supply, and includes a first impedance circuit and a second impedance from the commercial power supply. A power-saving power supply apparatus that supplies power to the control circuit via an output of a second rectifier circuit that is disposed between the first and second impedance circuits. Both the impedance circuit and the second impedance circuit are substantially resistors at the frequency of the commercial power supply, or one is substantially resistive at the frequency of the commercial power supply and the other is a reactance circuit. It is characterized by.

  In order to achieve the above object, the power saving power supply device according to claim 3 is the power saving power supply device according to claim 1 or 2, wherein the phase control of the control circuit is performed using a D-type FF.

  In order to achieve the above object, the power saving power supply device according to claim 4 is the power saving power supply device according to claims 1 to 3, wherein the phase difference can be arbitrarily set within a range of -20 degrees to +80 degrees. It is characterized by.

  In order to achieve the above object, a power saving power supply device according to claim 5 is the power saving power supply device according to claims 1 to 4, wherein the state of the load current and / or the load voltage on the transformer secondary side is passed through an insulating element. To the control circuit arranged on the primary side of the transformer to control intermittent or continuous operation of the switching circuit.

  In order to achieve the above object, the power saving power supply device according to claim 6 is the power saving power supply device according to claims 1 to 5, wherein the current flowing through the LED constituting the insulating element when the load current is larger than a predetermined value. The switching circuit is continuously operated by bypassing or shutting off, and the switching circuit is intermittently operated when the load current is not more than the predetermined value.

  In order to achieve the above object, a power-saving power supply device according to claim 7 includes a commercial power supply, a transformer having at least a primary winding, a secondary winding, and a tertiary winding, and an output of the secondary winding of the transformer. A bi-directional switching circuit for switching current from the commercial power supply to the primary winding of the transformer, and an on-time of the switching circuit is a voltage waveform of the commercial power supply. And a control circuit that controls the on / off state of the switching circuit at a timing with substantially the same phase difference with respect to the voltage waveform of the commercial power supply. Rectification is performed from the next winding by a third rectifier circuit, and power is supplied to the control circuit.

  To achieve the above object, the power saving power supply device according to claim 8 is the power saving power supply device according to claim 7, wherein the phase difference is controlled using a D-type FF.

  In order to achieve the above object, the power saving power supply device according to claim 9 is the power saving power supply device according to claim 7 or 8, wherein the phase difference can be arbitrarily set within a range of -20 degrees to +80 degrees. It is characterized by.

  In order to achieve the above object, the power saving power supply device according to claim 10 is the power saving power supply device according to claim 7 to 9, wherein the state of the load current and / or the load voltage on the secondary side of the transformer is passed through an insulating element. To the control circuit arranged on the primary side of the transformer to control intermittent or continuous operation of the switching circuit.

  In order to achieve the above object, the power saving power supply device according to claim 11 is the power saving power supply device according to claim 7 to 10, wherein the current flowing through the LED constituting the insulating element when the load current is larger than a predetermined value. The switching circuit is continuously operated by bypassing or shutting off the switching circuit, and the switching circuit is intermittently operated when the load current is not more than the predetermined value.

  In order to achieve the above object, a power-saving power supply device according to claim 12 is provided with a commercial power source, a first transformer having at least a primary winding and a secondary winding, and one of the first transformer from the commercial power source. In a power-saving power supply device including a bidirectional switching circuit that opens and closes a current flowing to a secondary winding, a first rectifier circuit that rectifies a secondary winding output of the first transformer, and the commercial power source is rectified. A second rectifier circuit, a second transformer having at least a primary winding and a secondary winding, and switching a current flowing from the output of the second rectifier circuit to the primary winding of the second transformer Switching means, and a third rectifier circuit that rectifies the current flowing in the secondary winding of the second transformer, and outputs of the first rectifier circuit and the third rectifier circuit are combined, Is it a detection means to detect current? And / or an operation state signal obtained from the load side is transmitted to the bidirectional switching circuit disposed on the primary side of the first transformer via the first insulating element. The opening / closing circuit is turned on.

  To achieve the above object, the power-saving power supply device according to claim 13 is the power-saving power supply device according to claim 12, wherein the output voltage of the first rectifier circuit is higher than the output voltage of the third rectifier circuit. It is characterized by being set.

  In order to achieve the above object, a power saving power supply device according to claim 14 is the power saving power supply device according to claim 12, wherein a detection circuit for detecting an output voltage of the third rectifier circuit is provided, so that the detection circuit A power source for controlling the switching means and controlling the output voltage of the third rectifier circuit via a second insulating element (not shown) is provided as an output of the first rectifier circuit. The LED constituting the second insulating element is turned on.

  In order to achieve the above object, a power saving power supply device according to claim 15 is the power saving power supply device according to claim 12, characterized in that the switching means is intermittent oscillation control.

  In the present invention, by replacing the capacitor as the reactance dropper with the resistor, it is very easy to manage the phase, and the ON section becomes an accurate 360 degrees, or an integral multiple thereof, and the efficiency in the intermediate current is reduced. It becomes difficult to get up. If it is around 45 degrees, which is a compromise between noise and efficiency, the noise will increase in principle because it will deviate from the zero-cross point, but this technology is not a problem because it has a large margin for noise. . Further, the power consumption of the dropper portion is increased by changing from the capacitor to the resistor, but the operating point of the transformer is improved, so that the standby power as a whole does not change so much or rather is improved. Also, changing from a capacitor to a resistor contributes to cost reduction.

  In Japanese Patent Laid-Open No. 2001-78446 and Japanese Patent Laid-Open No. 2001-352501, a capacitor is essential, but a resistor connected in series is mainly for ensuring safety when the capacitor is short-circuited.

  In other words, the ON / OFF timing is set to a phase around 45 degrees, which is a compromise between efficiency and noise, and the ON time is set to an exact integer multiple of 360 degrees, thereby reducing the efficiency drop at intermediate currents. . For this purpose, it is important to eliminate the reactance dropper, that is, the capacitor and replace it with a resistor.

  The exclusion of the capacitor includes a state in which at least one of the first impedance circuit and the second impedance circuit has a pure resistance or can be regarded as a substantial resistance at an input commercial frequency.

  According to the first or second aspect of the invention, by replacing the capacitor with a resistor, the phase can be easily managed, and the ON section becomes an accurate 360 degrees or an integral multiple thereof, so that the efficiency at the intermediate current can be improved. The decrease is less likely to occur.

  The phase control of the control circuit according to the third aspect of the invention is performed using a D-type FF, whereby the circuit can be simplified and the cost can be reduced.

  Since the phase difference of the invention of claim 4 can be arbitrarily set in the range of −20 degrees to +80 degrees, the efficiency and noise can be set according to the purpose of the product.

  The state of the load current and / or the load voltage on the transformer secondary side according to claim 5 is transmitted to the control circuit arranged on the primary side of the transformer via the insulating element to control the intermittent or continuous operation of the switching circuit. Thus, the output voltage on the secondary side can be kept within a certain range.

  When the load current of claim 6 is larger than a predetermined value, the switching circuit is continuously operated by bypassing or interrupting the current flowing through the LED constituting the insulating element, and when the load current is less than the predetermined value, the switching circuit is switched. As a result, the critical point between the intermittent operation and the continuous operation can be determined with a predetermined current regardless of the level of the input voltage.

  According to the invention of claim 7, by replacing the capacitor with a resistor, it is easy to manage the phase, and the ON section becomes an accurate 360 degrees, or an integral multiple thereof, and the efficiency at the intermediate current is reduced. It becomes difficult to occur, and current can be supplied to the control circuit from the tertiary winding of the transformer.

  The phase control of the control circuit according to the eighth aspect of the invention is performed using a D-type FF, whereby the circuit can be simplified and the cost can be reduced.

  Since the phase difference of claim 9 can be arbitrarily set within the range of -20 degrees to +80 degrees, the efficiency and noise can be set according to the purpose of the product.

  The state of the load current and / or the load voltage on the transformer secondary side according to claim 10 is transmitted to a control circuit arranged on the primary side of the transformer via an insulating element to control intermittent or continuous operation of the switching circuit. Thus, the output voltage on the secondary side can be kept within a certain range.

  When the load current of claim 11 is larger than a predetermined value, the switching circuit is continuously operated by bypassing or interrupting the current flowing through the LED constituting the insulating element, and when the load current is less than the predetermined value, the switching circuit is switched. As a result, the critical point between the intermittent operation and the continuous operation can be determined with a predetermined current regardless of the level of the input voltage.

  According to the twelfth aspect of the present invention, it is possible to operate a switching power supply that consumes less power during standby at light loads, and to configure a power supply with less EMI noise during normal operation.

  According to the thirteenth aspect of the invention, since the output voltage of the first rectifier circuit is set higher than the output voltage of the third rectifier circuit, the operation can be switched reliably according to the load current.

  According to the invention of claim 14, by using the output of the first rectifier circuit to turn on the LED constituting the second insulating element that transmits the control signal for controlling the output voltage of the third rectifier circuit, It is possible to smoothly switch between the power source on the transformer 114 side operated by a commercial power source and the power source on the transformer 214 side operated at a high frequency. (Figure 3)

  According to the fifteenth aspect of the invention, since the switching means is intermittent oscillation control, an efficient operation is possible.

  FIG. 1 shows a first embodiment of the present invention. The commercial power supply 100 is applied to the primary winding 114a of the transformer 114 via an AC switch composed of 112 and 112b. On the other hand, the control power supply is rectified by the zener diode 103 and the diode 104 that also serve as overvoltage protection such as lightning surge from the commercial power supply 100 via the first impedance circuit 101R, and passes through the second impedance circuit 102R. Return to the commercial power source 100. The output of the diode 104 is smoothed by the capacitor 109, the + side of the capacitor 109 is connected to Vcc of the control IC 140, and the-side is connected to Vss, and serves as a power source for operating the D-type flip-flop as the control IC.

  The intersection of the Zener diode 103 and the diode 104 is a substantially square wave, but enters the CLOCK input of the D-type flip-flop via the RC filter by the resistor 107 and the capacitor 108 which also serves as a high-frequency noise filter and waveform delay. The DATA terminal is connected from Vcc through the resistor 110, and is also connected to the collector of the transistor 111 of the photocoupler 150. The emitter of the transistor 111 is connected to Vss. The Q terminal drives an AC switch 112 and 112b. When the Q terminal is at a high level, the AC switch is turned on.

  The secondary winding 114b of the transformer 114 is rectified by the rectifier circuit 115a, smoothed by the capacitor 117, and further passed through the current detection resistor 120 to be output. When the output voltage rises at a light load and becomes equal to or higher than the voltage set by the Zener diode 130, the LED 119 is lit and the primary transistor 111 is turned on, the DATA terminal is set to low level, and the Q terminal is also set to low level. Thus, the switching circuit is turned off. The resistor 118 is for current limitation. When the output voltage decreases, the LED becomes dark and the primary transistor 111 is turned off, the DATA terminal is set to the high level, the Q terminal is also set to the high level, the switching circuit is turned on, and the output voltage is increased again. . By repeating this operation, the output voltage is maintained within a certain range.

  In order to stabilize the switching point (critical current) between the continuous mode and the intermittent mode regardless of whether the input voltage is AC90V or AC110V, a current detection resistor 120 is provided. When the current exceeds the critical current, the transistor 128 is turned on, bypassing the current of the LED 119, forcing the continuous mode. Another transistor 127 is for temperature compensation and resistors 125 and 126 are for bias.

  The current detection circuit used here is not an overcurrent protection circuit that works when a general rated current is exceeded, but a critical current detection circuit that detects a critical point between intermittent operation and continuous operation. By providing this circuit, the critical point between the intermittent operation and the continuous operation can be determined stably with a predetermined current even when the input voltage is high or low. In this operation, when the current exceeds the critical current, the LED 119 of the photocoupler 150 is short-circuited to force a continuous operation.

  The tertiary winding 114d and the diode 141 wound around the transformer are for supplying supplementary current when the current for the control circuit is insufficient, and are not necessarily required.

  The present invention may be configured in one device or may be divided into two or more separate devices. As an example, a configuration in which the transformer and the primary side circuit of the present invention are configured as an AC adapter, and the secondary side circuit of the transformer including the rectifier circuit 115a is arranged in a device that uses the output of the AC adapter as a power source. It is done.

FIG. 2 shows a second embodiment. Only the changes will be described below. Since the current flowing through the second impedance circuit 102R is also rectified by the diodes 105 and 106, about half of the current is sufficient as compared with FIG. 1, so the power consumption due to the resistance of this impedance circuit is halved.
The AC switch has two FETs 112 and 113 in series, but the operation is the same. The diodes 112a and 113a are FET body diodes.

  An overcurrent limiting circuit has been added on the secondary side, but a device that uses a common current detection resistor 120 has been devised, so that the current flowing to the LED 119 with the transistor 131 above the critical current is cut off. It is configured. When the current exceeds the overcurrent, the current flows again to the LED 119 through another route by the transistor 124 to limit the overcurrent. 1 and 2, the impedance circuit is divided into first and second, but in the case of an element in which the AC switch is insulated, for example, if it is an element such as a photovolt or a photo MOS, There may be only one impedance circuit (in a state where 102R is short-circuited). Since the source of the MOSFET used in FIGS. 1 and 2 cannot be isolated from the control circuit, pseudo-insulation is created by dividing the impedance circuit into two.

  In this way, when the impedance circuit is divided into two, depending on the circuit, the object of the present invention can be achieved even if only one impedance circuit is used as a resistor. For example, in the case of FIG. 1, if only the 102R side on which the AC switch is arranged is a resistor, the required effect can be obtained even if the 101R side is a capacitor.

  FIG. 3 shows a third embodiment. When the power source on the transformer 114 side operating at the commercial frequency and the switching power source operating on the side of the switching transformer 214 operating at a high frequency are connected in parallel and the load current is small, the switching power source side operates and the load current is In many cases, the transformer 114 is configured to perform a dominant operation. Detailed description on the side of the transformer 114 operating at a commercial frequency is omitted.

  The current passing through the inrush current preventing resistor 201 is rectified by the bridge diode 202 and further smoothed by the smoothing capacitors 203 and 204. The inductor 205 is for countermeasures against switching noise.

  The control IC 211 here is an example of what is called a link switch of Power Integrations. It should be noted that a better effect can be obtained by configuring the control IC for a switching power supply that operates intermittently. Capacitors 209 and 210, resistors 206 and 208, and a diode 207 are external components for operating this IC, and together with these, the current flowing through the primary winding 214a of the switching transformer 214 is switched. The secondary winding 214b is rectified by the diode 214 and is in parallel with the power supply output on the transformer 114 side. Incidentally, since the control IC 211 has a function of inferring and controlling the output voltage on the secondary side from the voltage generated in the primary winding 214a, the feedback circuit from the secondary side can be omitted.

  When the load current is small, only this switching power supply works. When the load current increases, the voltage generated in the resistor 120 turns on the transistor 128 and turns on the LED 119 of the photocoupler 150 called a photovoltaic. The transistor 127 is for temperature compensation, the resistors 125 and 126 are for bias, and the resistor 118 is for current limiting. A current flows through the photodiode 212 on the light receiving side of the photocoupler 150 to turn on the FET 112 and operate the power supply on the transformer 114 side. The output voltage of the transformer 114 side power supply is set slightly higher than that of the switching power supply side. For this reason, when the transformer 114 side operates, the switching power source side restricts the output current, and the transformer 114 side becomes the dominant operation. With this configuration, it is possible to operate a switching power supply with low standby power consumption at light loads, and to configure a power supply with low EMI noise during normal operation. 213 is for discharging the gate charge of the FET 112 when the photodiode 212 is turned off.

  In general switching power supplies, for example, a reference voltage element (not shown) such as TL431 and a photocoupler (not shown) are often used for controlling the secondary side voltage. In such a case, when the power supply on the transformer 114 side operates, for example, the switching power supply side can be stopped by applying a high voltage to the detection terminal of the reference voltage element. Alternatively, the photocoupler LED driven by the reference voltage element may be configured to light up directly when the power source on the transformer 114 side operates. In this way, when the power source on the transformer 114 side works, the switching power source side may be configured to stop from the secondary side via the LED of the photocoupler.

  When there is a control signal that informs that it is operating on the load side, the load is operating using this control signal without detecting that the load is operating using the load current detection resistor 120. In some cases, the LED 119 of the photocoupler 150 may be directly turned on.

  In the conventional circuit of FIG. 4, both the first impedance circuit 101C and the second impedance circuit 102C are capacitors. When the ON phase is 0 degrees and the OFF phase is delayed by 30 degrees and one cycle is conducted, the operation is actually 390 degrees. Therefore, the peak current of the inrush current in the next cycle is 680 mA (FIG. 7). However, when both the first impedance circuit and the second impedance circuit are changed to the resistors 101R and 102R as shown in FIG. 1, the on-phase is 45 degrees and the off-phase is 45 degrees behind, and the conduction angle 360 degrees, the symmetry was improved, the generation of residual magnetic flux was small, and the peak current was drastically reduced to 204 mA (FIG. 7).

  In this way, changing the capacitor to a resistor may seem like a slight change in the circuit, but I found out that the cause of the efficiency drop at the intermediate current is due to the operation of the transformer. It is an invention born as a result of careful examination of countermeasures. Moreover, this effect has been improved brilliantly as can be seen from the data graphs of FIGS. 5 and 6, and although an increase in noise due to deviation from the zero cross point is recognized, it still falls within the standard. Yes. If a capacitor that only allows reactive current to flow is changed to a resistor that consumes active power, the power consumption can be increased. However, since the inrush current of the transformer is reduced, the overall efficiency is rather improved. Changing from a capacitor to a resistor can be used to simplify the invention, but it can also be used for more advanced things.

1 is a first embodiment of the present invention. It is the 2nd Embodiment of this invention. It is the 3rd Embodiment of this invention. It is a conventional circuit. It is a data graph of this invention. It is a data graph of this invention. It is a data graph of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Commercial power supply 101 1st impedance circuit 102 2nd impedance circuit 103 Diode 104 Diode 105 Diode 106 Diode 107 Resistance 108 Capacitor 109 Capacitor 110 Resistance 111 Transistor 112 AC switch 113 AC switch 114 Transformer 115 Rectification circuit 116 Rectification circuit 117 Capacitor 118 Resistor 119 LED
120 Resistor 121 Resistor 122 Resistor 123 Transistor 124 Transistor 125 Resistor 126 Resistor 127 Transistor 128 Transistor 129 Resistor 130 Diode 131 Transistor 150 Insulating Element 214 Transformer 215 Diode

Claims (15)

A commercial power source, a transformer having at least a primary winding and a secondary winding, a first rectifier circuit that rectifies the output of the secondary winding of the transformer, and the commercial power source to the primary winding of the transformer A bidirectional switching circuit that opens and closes a flowing current, and the on-time of the switching circuit is one cycle or an integral multiple of the voltage waveform of the commercial power supply. And a control circuit that controls the phase difference at substantially the same phase difference, and a second rectifier circuit disposed from the commercial power source via an impedance circuit supplies power to the control circuit. ,
The power-saving power supply device, wherein the impedance circuit is substantially a resistor at a frequency of the commercial power supply. A commercial power source, a transformer having at least a primary winding and a secondary winding, a first rectifier circuit that rectifies the output of the secondary winding of the transformer, and the commercial power source to the primary winding of the transformer A bidirectional switching circuit that opens and closes a flowing current, and the on-time of the switching circuit is one cycle or an integral multiple of the voltage waveform of the commercial power supply. And a control circuit for controlling at a timing of substantially the same phase difference from the commercial power source via the first impedance circuit and the second impedance circuit, and the first and second impedance circuits In the power-saving power supply device in which the output of the second rectifier circuit arranged between the two supplies power to the control circuit,
Both the first impedance circuit and the second impedance circuit are substantially resistive at the frequency of the commercial power source, or one is substantially resistive at the frequency of the commercial power source and the other is a reactance circuit A power-saving power supply device. 3. The power-saving power supply device according to claim 1, wherein phase control of the control circuit is performed using a D type FF. 4. The power-saving power supply device according to claim 1, wherein the phase difference can be arbitrarily set within a range of −20 degrees to +80 degrees. The state of the load current and / or the load voltage on the secondary side of the transformer is transmitted to the control circuit arranged on the primary side of the transformer via an insulating element to control intermittent or continuous operation of the switching circuit. The power-saving power supply device according to claim 1. When the load current is larger than a predetermined value, the switch circuit is continuously operated by bypassing or blocking the current flowing through the LED constituting the insulating element, and when the load current is less than the predetermined value, the switch circuit is 6. The power saving power supply device according to claim 1, wherein an intermittent operation is performed. A commercial power source, a transformer having at least a primary winding, a secondary winding, and a tertiary winding; a first rectifier circuit that rectifies the output of the secondary winding of the transformer; A bidirectional switching circuit that opens and closes a current to the primary winding; and an on-time of the switching circuit is one cycle of the voltage waveform of the commercial power source or an integral multiple thereof. In a power-saving power supply device comprising a control circuit that controls at a timing of substantially the same phase difference with respect to the voltage waveform of the commercial power supply,
A power-saving power supply device that rectifies the tertiary winding of the transformer by a third rectifier circuit and supplies power to the control circuit. 8. The power saving power supply apparatus according to claim 7, wherein the phase difference is controlled using a D type FF. The power saving power supply device according to claim 7 or 8, wherein the phase difference can be arbitrarily set in a range of -20 degrees to +80 degrees. The state of the load current and / or the load voltage on the secondary side of the transformer is transmitted to the control circuit arranged on the primary side of the transformer via an insulating element to control intermittent or continuous operation of the switching circuit. The power-saving power supply device according to claim 7. When the load current is larger than a predetermined value, the switch circuit is continuously operated by bypassing or blocking the current flowing through the LED constituting the insulating element, and when the load current is less than the predetermined value, the switch circuit is The power-saving power supply device according to claim 7, wherein the power-saving power supply device is intermittently operated. A commercial power source, a first transformer having at least a primary winding and a secondary winding, and a bidirectional switching circuit for switching current flowing from the commercial power source to the primary winding of the first transformer. In power saving power supply
A first rectifier circuit for rectifying the secondary winding output of the first transformer; a second rectifier circuit for rectifying the commercial power supply; and a second transformer having at least a primary winding and a secondary winding. Switching means for switching the current flowing from the output of the second rectifier circuit to the primary winding of the second transformer, and third means for rectifying the current flowing in the secondary winding of the second transformer A rectifier circuit,
The outputs of the first rectifier circuit and the third rectifier circuit are combined, and the detection signal from the detection means for detecting the combined current and / or the operation state signal obtained from the load side are used as the first insulating element. A power-saving power supply device, wherein the switching circuit is turned on by transmitting to the bidirectional switching circuit disposed on the primary side of the first transformer via the switch. 13. The power saving power supply device according to claim 12, wherein an output voltage of the first rectifier circuit is set higher than an output voltage of the third rectifier circuit. By providing a detection circuit for detecting an output voltage of the third rectifier circuit, a detection signal output from the detection circuit controls the switching means via a second insulating element, and the third rectifier circuit 13. The power saving power supply apparatus according to claim 12, wherein an LED constituting the second insulating element is turned on by an output of the first rectifier circuit in a power source for controlling the output voltage of the first rectifier circuit. 13. The power saving power supply device according to claim 12, wherein the switching means is intermittent oscillation control.

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