KR20020038628A - SMPS : Switching Mode Power Supply - Google Patents

Abstract

PURPOSE: A switching power supply device capable of corresponding to an output voltage change is provided to receive output voltage change information from a load terminal and change it to a required output voltage. CONSTITUTION: A microcomputer senses an inner temperature of a storage room and controls a voltage applied to a thermoelement based on the sensed inner temperature of a storage room in order to uniformly maintain the inner temperature of the storage room. When a high level signal is outputted to an output terminal of the microcomputer(U3), a transistor(TR) and an FET are turned on and off so that a voltage is not applied to a thermoelement so that an output of the comparator(U4) is high. When two high level pulses from a load side are outputted, two high level pulses are generated in a first input terminal(I1) of a control microcomputer(U3).

Description

Switching power supply with variable output voltage {SMPS: Switching Mode Power Supply}

The present invention relates to a "switching power supply device [SMPS] capable of variable output voltage response", and in the device operating by receiving DC power from the switching power supply device of the switching power supply from the device side [switching power supply side] The present invention relates to the improvement of energy efficiency, reliability, and value increase of the device by receiving the information on the change of the output voltage and changing the output voltage of the switching power according to the change. In a device operating using a conventional switching power supply configured as shown in FIG. 1, when the device needs to vary energy consumption, the on / off control should be performed inside the device. In this case, there is a problem in reliability and energy efficiency of the device. Occurs. For example, a conventional switching power supply configured as shown in FIG. 1 is used, and a cooling element [TEC; In the case of Kimchi refrigerator, cosmetic refrigerator, etc., using the “Electric Electric Couple”, when the internal temperature of the storage reaches the target value, the temperature applied to the thermoelectric element is controlled on and off so that the internal temperature of the storage is kept constant. In addition, it is necessary to control the speed of the heat sink cooling fan while keeping the power applied to the thermoelectric element at the rated voltage so that the internal temperature of the storage is kept constant. When the power applied to the cooling thermoelectric element is controlled on and off, not only does it cause a problem in the life of the thermoelectric element, but also the energy efficiency is deteriorated because cold air in the reservoir flows out through the heat sink during the off period. In addition, if the power applied to the thermoelectric element is kept at the rated voltage, the speed of the fan motor that cools the heat sink is controlled to maintain the high internal temperature of the storage. As a result of lowering the cooling efficiency, as a result, the thermoelectric element is operated more than necessary, and thus there is a problem of lowering energy efficiency and reliability. However, in order to vary the output voltage of the switching power supply in response to the demand of the load, an additional third line for communication is required separately from the two output power supply lines. In this case, all the connecting jacks for the power supply are 2 It is wired, so it is necessary to change the appearance mold of the device, to develop a new three-wire power cord and jack, and to share the material.

Therefore, the object of the present invention devised to solve such a problem is to receive the information on the output voltage variable from the load end side while maintaining the output line of the switching power supply in two wires, and outputs the variable to the output voltage that meets the requirements It is to provide a "switching power supply capable of variable output voltage".

1 is a diagram showing an example of a circuit configuration of a conventional switching power supply of a conventional system.

2 is a diagram showing an example of a circuit configuration of a switching power supply capable of variable output voltage according to the present invention.

3 is a diagram showing an example of a circuit configuration of a device used with a switching power supply capable of variable output voltage according to the present invention.

Figure 4 is a timing diagram showing an embodiment in which the switching power supply capable of variable output voltage according to the present invention receives a control pulse from the load side [Fig. 4 (1)], the output voltage is variable [Fig. 4 (2)].

<Explanation of the code | symbol about the principal part of drawing>

One ; Input power rectifier circuit block

2 ; Switching circuit block

3; Switching transformer peripheral circuit block

4 ; Switching Power Output Voltage Feedback Circuit Block

5; Monitoring of communication contents from load and variable output circuit block

D _{1 to} D ₉ ; 1st to 9th diodes

C ₁ -C _ll ; 1st to 11th condenser

R _S ; Shunt Resistance

R ₁ to R _ll ; 1st to 11th resistors

F; Hughes

L; coil

NTC; Negative temperature resistance

T ₁ ; Switching transformer

U ₁ ; Voltage sensing integrated circuit

U ₂ ; regulator

U ₃ ; Control

U ₄ ; Comparator

P _C ; Photocoupler

Vo; Output voltage

A feature of the "switching power supply capable of variable output voltage" according to the present invention for achieving the above object is to change the output voltage from the load by monitoring the output line while keeping the output voltage of the switching power supply constant. If the information is delivered to the appropriate voltage to include a step of outputting. When the output voltage of the switching power supply is changed to a voltage that meets the demand of the load, the output power of the switching power supply can provide the effect of improving energy efficiency and reliability to the device [load] using the switching power supply. It will provide an increase in the value of the device.

Hereinafter, a preferred embodiment of the "switching power supply apparatus [SMPS] capable of variable output voltage" according to the present invention will be described in detail with reference to the accompanying drawings. 1 is a circuit configuration example of a conventional switching power supply, and is output at a constant voltage [eg, Vo = l2V].

U ₁ is a voltage sensing integrated circuit that detects 2.5V

Vo is fixed at the desired voltage and output. Figure 2 is a circuit diagram of a preferred embodiment of the "switching power supply capable of variable output voltage" according to the present invention. Reference numeral 1 denotes an input power rectifier circuit block and reference numeral 2 denotes a switching circuit block. Reference numeral 3 denotes a switching transformer peripheral circuit block, and reference numeral 4 denotes a switching power supply output voltage feedback circuit block. Reference numeral 5 denotes a communication block for monitoring the communication from the load and an output voltage variable circuit block. When the first output terminal [O ₁ ] of the control microcomputer [U ₃ ] is output low [Low = 0V], D ₁₀ is turned off.

If R ₅ = 3.8kΩ and R ₆ = 1.0kΩ, Vo = l2V is output. When the voltage at the first output terminal [O ₁ ] of the control microcomputer [U ₃ ] rises, D ₁₀ is turned on so that the current supply source of the sixth resistor [R ₆ ] becomes two places and the current from the fifth resistor [R ₅ ]. Must decrease, resulting in the output voltage [Vo] going down. In this way, the output voltage is controlled by controlling the current flowing through the tenth diode [D ₁₀ ]. The control microcomputer [U ₃ ] monitors the first input terminal [I ₁ ] to determine the output voltage variable requirement from the load side.

If the load current is I when the load is ON

At this time, the relationship between the negative input terminal voltage [V _(-) ] and the positive input terminal voltage of the comparator [U ₄ ]

Setting R ₉ , R ₁₀ , R _S and I to make the output of comparator [U ₄ ] low. When the load current is cut off at the load side, the current flowing in the load flows only the standby current [Standby Current]. Thus, the positive input terminal voltage of the comparator [U ₄ ] is higher than the negative input terminal voltage, and the output of the comparator [U4] becomes High [High]. Therefore, the control microcomputer [U ₃ ] can grasp the content of the communication from the load by monitoring the input state to the first input terminal [I ₁ ].

FIG. 3 is a circuit block of an embodiment of a device [store] that can be used with the " switching power supply capable of variable output voltage " according to the present invention. The microcomputer detects the high temperature in the storage room and detects the high temperature inside the storage room by using the analog input terminal [AD in] .The voltage applied to the cooling thermoelectric element (L) should be lowered or raised, or the current voltage. You will decide if you need to keep it. When the microcomputer output terminal [Out] becomes high, TR is turned on, the FET is turned off, and the voltage applied to the thermoelectric element is also turned off. As a result, the output of the comparator [U ₄ ] in FIG. 2 becomes high. Therefore, when two high pulses are output from the load side [reservoir side] configured as shown in FIG. ₃ , the first input terminal [I ₁ ] of the control microcomputer [U ₃ ] of the switching power supply configured as shown in FIG. Two high pulses are generated. therefore

Two pulses; [1 Step] Voltage Drop

1 pulse; [1 Step] voltage rise

No pulse; Maintain current voltage

The voltage change requirement can be transmitted from the load side to the switching power supply, and the switching power supply side can output a variable voltage corresponding thereto. 4 is a timing diagram of an embodiment in which an output voltage is varied according to communication contents from a load.

As described above, the "switching power supply capable of variable output voltage" according to the present invention receives a voltage change requirement from the load side while using a conventional 2-wire output cord wire and a plug terminal, and outputs it as required by the load side. By changing the voltage and outputting it, the reliability of a device using a switching power supply such as a storage lamp is improved, and the energy efficiency is improved, resulting in the effect of increasing the value of the device.

Although the above has been illustrated and described with respect to the preferred embodiment of the present invention, the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the invention as claimed in the claims of the present invention. Such changes are intended to fall within the scope of the claims.

Claims (1)

The switching power supply device receives the output voltage change request by intermittently changing the load current from the load side, and converts the output voltage into a voltage corresponding to the load request by outputting the output voltage change request data into a shunt resistor and a comparator. "Switching power supply capable of variable output voltage".