JP2853207B2 - Power supply system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power supply system for transmitting electric power.

[Conventional technology]

FIG. 3 is a cross-sectional view showing a conventional outlet utilizing the electromagnetic induction effect disclosed in, for example, Japanese Utility Model Laid-Open No. 57-31818. In the figure, (1) is a commercial AC power supply, (20a) is a primary core, and (7a) is a primary winding wound around the primary core (20a), and constitutes an outlet body (21). .
(20b) is the secondary core, and (7b) is the secondary core (20
The secondary winding is wound around b) and constitutes an outlet cap (plug) (22). (23a) is a cord from the commercial AC power supply (1) to the primary winding (7a), (23b) is a cord from the secondary winding (17b) to the load (14), (24a) and (24b) are primary windings (7
a) A bobbin for winding the secondary winding (7b).

Next, the operation of this conventional example will be described. In a conventional outlet using a transformer, an outlet cap (plug) (22) on the secondary side of the transformer is connected to an outlet body (21) on the primary side of the transformer, and an AC voltage is supplied from a commercial AC power supply (1). 23a), the primary winding (7
Current flows through a) and the primary core (20a) and the secondary core (20a).
b) Magnetic flux is generated. This magnetic flux causes electromagnetic induction to cause a current to flow through the secondary winding (7b), thereby extracting AC electric energy from the cord (23b) and supplying power to the load (14).

[Problems to be solved by the invention]

Since the power supply system such as a conventional outlet is configured as described above, when a load fluctuation or an input voltage fluctuation occurs, the output voltage or the output current fluctuates according to the fluctuation, and it is impossible to obtain a stable output. It was possible. Also, if molding is performed on the primary and secondary sides of the transformer, respectively, the leakage inductance increases,
There was a problem that the fluctuation rate became larger.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can suppress a fluctuation in an output voltage or an output current due to a load fluctuation or an input voltage fluctuation, and can obtain a stable output with high accuracy. It is an object of the present invention to provide a highly reliable power supply system in which a large loss for voltage adjustment does not occur even if the power supply becomes large, the temperature rise due to heat generation is low.

[Means for solving the problem]

A power supply system according to the present invention includes a first transformer waiting for a structure capable of freely separating and coupling a primary winding and a secondary winding, and a switching element connected to the primary winding. A switching regulator provided with an inverter that converts direct current to alternating current and supplies it to the primary winding, and a rectifier circuit connected to the secondary winding and supplying direct current to the load, the output voltage or output current of the rectifier circuit. Detection means for detecting a corresponding signal as a detection signal, conversion means for converting the detection signal into a frequency signal corresponding to the detection signal, a structure capable of freely separating and coupling the transmission side winding and the reception side winding And a second transformer for transmitting a frequency signal from the transmission winding and receiving the reception signal at the reception winding, and exclusively controlling the switching time of the switching element according to the frequency signal received by the reception winding of the second transformer. Rectifier circuit Those having a control unit for controlling the load voltage or load current of the load by controlling the force voltage or output current.

[Action]

The power supply system according to the present invention controls the switching time of the switching element exclusively in accordance with the frequency signal which is a signal corresponding to the output voltage or the output current of the rectifier circuit connected to the secondary winding, thereby controlling the output of the rectifier circuit. The load voltage or the load current is controlled by controlling the voltage or the output current. Therefore,
The load voltage or load current can be controlled only by controlling the switching time of the switching element. Even if the load increases, no large loss occurs for voltage adjustment, and the temperature rise due to heat generation is reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a power supply system according to an embodiment of the present invention, which relates to a forward converter type power supply system having an output voltage control loop. In the figure, (1), (7a), (7b), and (14) are the same as or correspond to the conventional outlets, and are denoted by the same reference numerals. (2) is a rectifying diode bridge, and (3) is a smoothing capacitor. The AC / DC converter (4) is composed of a commercial AC power supply (1), a diode bridge (2), and a smoothing capacitor (3). (5) is the AC / DC converter (4)
(6) is a control circuit for outputting an opening / closing signal for the switching element (5), (7) is a first transformer, and (7)
c) is a snubber winding for initializing the first transformer (7), (8) is a separation unit of the power supply system, and (9) is a snubber diode. (10) and (11) are rectifier diodes, (12) is a choke coil, and (1)
3) is a smoothing capacitor, (15) is an output voltage detection circuit for detecting an output voltage, (16) is a voltage / frequency conversion circuit for converting a voltage signal to a frequency signal, and (17) is a second
(17a) is a transmission side winding of the second transformer (17), (17b) is a reception side winding, and (18) is a frequency / voltage conversion circuit for converting a frequency signal into a voltage signal. is there.

In the power supply system configured as described above, the AC voltage applied from the commercial AC power supply (1) is rectified and smoothed by the rectifying diode bridge (2) and the smoothing capacitor (3) to obtain a DC voltage. The switching element (5) performs a switching operation in response to the opening / closing signal output from the control circuit (6). On the secondary side, the intermittent energy sent from the primary side AC / DC converter (4) is converted into a rectifier diode (1) on the secondary winding (7b) side of the first transformer (7).
The DC output voltage is supplied to the load (14) by rectifying by the 0) and (11) and averaging by the LC filter composed of the choke coil (12) and the smoothing capacitor (13).
Energy is transmitted to the secondary winding (7b) side of the first transformer (7) by the separating portion (8), and is performed by electromagnetic induction when the switching element (5) is turned on. When the separating section (8) is in the separated state, electromagnetic induction cannot be performed and energy is not transmitted. The snubber winding (7c) of the first transformer (7) is provided to initialize the first transformer (7) when the switching element (5) is turned off, and passes through the snubber diode (9). The first transformer (7)
Is stored in the capacitor (3). The DC output voltage supplied to the load (14) is detected by an output voltage detection circuit (15). Needless to say, the detection circuit (15) may be a circuit that detects a voltage obtained by dividing the output voltage as long as the output voltage information is known.
The detected voltage signal is converted to a voltage / frequency conversion circuit (16)
Is transmitted to the second transformer (17) as a frequency signal. The second transformer (17) can be separated and combined by the separation unit (8) in conjunction with the first transformer (7), and the separation unit (8) can combine the frequency signal with the second transformer when the separation unit (8) is in the combined state. (17) From the transmission winding (17a) to the reception winding (17a)
b) can be communicated. The frequency signal transmitted to the primary side is sent to a frequency / voltage conversion circuit (18), and the control circuit (6) controls opening and closing of the switching element (5) by the converted voltage signal to control the output voltage. .

Therefore, output fluctuation due to load fluctuation or input voltage fluctuation is suppressed, and a stable output with high accuracy can be obtained. Further, overvoltage can be detected and protected.

Further, since the transformer is used as the outlet, there is no danger of contact failure due to conductor pieces, electric shock or electric leakage, and power can be supplied safely in a place where water is splashed or outdoors.

In the above-described embodiment, the detection of the output voltage information as the output signal has been described. However, the detection of the output current information may be performed. Hereinafter, another embodiment of the present invention having an output current detection circuit will be described with reference to the drawings. FIG. 2 is a block diagram showing this embodiment.
(1) to (14) and (16) and (18) are the same as those shown in FIG. 1 of the above embodiment. (19) is an output current detection circuit for detecting an output current.

In this embodiment, a DC output current supplied to a load (14) is detected by an output current detection circuit (19) and output as a voltage signal. It is needless to say that the detection circuit (19) may be a circuit for detecting a current obtained by dividing the output current, as long as the output current information is known. The detected current signal is fed back in the same manner as in the above embodiment, and the opening and closing of the switching element (5) is controlled by the control circuit (6) to control the output current.

In the above embodiment, the case where the commercial AC power supply (1) is applied has been described. However, there is no problem even if another AC power supply is used. Instead of the AC / DC converter (4), a DC power supply, for example, a battery is used. May be. In addition, the forward converter type power supply system has been described, but other types of switching regulators, for example, a push-pull type,
Needless to say, a half-bridge type, a full-bridge type, a flyback type, or the like may be used, and an AC output may be obtained without the rectifying and smoothing circuit on the secondary side of the first transformer (7). .

〔The invention's effect〕

As described above, according to the present invention, the first transformer and the switching element connected to the primary winding wait for a structure capable of freely separating and coupling the primary winding and the secondary winding. A switching regulator provided with an inverter for converting DC to AC and supplying it to the primary winding and a rectifier circuit connected to the secondary winding and supplying DC to the load; output voltage or output of the rectifier circuit Detection means for detecting a signal corresponding to the current as a detection signal, conversion means for converting this detection signal into a frequency signal corresponding to the detection signal, and a transmission side winding and a reception side winding can be freely separated and coupled. Transformer having a simple structure and transmitting a frequency signal from a transmission side winding and receiving at a reception side winding, and switching time of the switching element exclusively according to the frequency signal received by the reception side winding of the second transformer Control the rectifier circuit Since a control device that controls the load voltage or load current of the load by controlling the output voltage or output current is provided, output fluctuations due to load fluctuations or input voltage fluctuations are suppressed, and a highly accurate and stable output can be obtained. Not only can overvoltage or overcurrent be detected and protected, but the load voltage or load current can be controlled only by controlling the switching time of the switching element, and even if the load becomes large, a large loss for voltage adjustment occurs. In addition, temperature rise due to heat generation is reduced, and reliability is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a power supply system according to an embodiment of the present invention having an output voltage control loop, and FIG. 2 is a power supply system having an output current control loop according to another embodiment of the present invention. FIG. 3 is a sectional view showing a conventional outlet using electromagnetic induction. (5) is a switching element, (6) is a control circuit, (7)
Is a first transformer, (8) is a separation unit, (15) is an output voltage detection circuit, (16) is a voltage frequency conversion circuit, and (17) is a second
, (18) is a frequency-voltage conversion circuit, and (19) is an output current detection circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H02J 3/00-7/12 H02J 7/34-7/36 H02J 17/00

Claims (1)

(57) [Claims] A first transformer which waits for a structure capable of freely separating and coupling a primary winding and a secondary winding, and a switching element connected to the primary winding. And an inverter for converting the AC power into AC and supplying the AC power to the primary winding.
A switching regulator provided with a rectifier circuit connected to the secondary winding and supplying a direct current to a load, a detecting means for detecting a signal corresponding to an output voltage or an output current of the rectifier circuit as a detection signal, and detecting the detection signal A converting means for converting the signal into a frequency signal according to a signal; a structure capable of freely separating and coupling a transmission side winding and a reception side winding; transmitting the frequency signal from the transmission side winding to the reception side winding; Controlling the output voltage or output current of the rectifier circuit by exclusively controlling the open / close time of the switching element according to the frequency signal received by the second transformer received by the line and the receiving winding of the second transformer. A power supply system including a control device that controls a load voltage or a load current of the load by performing the control.