CN102185497A - Automatic power-off device - Google Patents

Abstract

The invention discloses an automatic power-off device, belonging to the field of electronic automatic switches. The automatic power-off device comprises a DC (direct current) supply module, a power supply control module and a current sampling module, wherein the DC supply module is accessed to an AC (alternating current) supply module via a switch to acquires electrical energy and supply the electrical energy to the power supply control module, the current sampling module takes the sampling current obtained from a mutual inductor as a control signal and provides the control signal to the power supply control module, the power supply control module controls the switch by a timer and a relay to realize an automatic power-off function. The automatic power-off device utilizes the relay technology to realize automatic power-off of the circuit; the circuit structure is simple, the cost is low, the practical applicability is high and the security of the use of electricity can be improved.

Description

An automatic power-off device

technical field

The invention relates to a switch device capable of automatically cutting off power, and belongs to the technical field of electric power automatic switches.

Background technique

With the rapid development of our country's economy, our country's consumption of electric energy is also increasing, especially the "power shortage" problem faced by major cities, which has had a great impact on social development and people's lives. Although the relevant government departments China and the media continue to increase publicity and take some measures, but the results are not obvious so far. The problem of "electricity shortage" is still serious, and its scope of influence is getting wider and wider.

There are also several effective energy-saving measures:

1) By reducing the power consumption of electrical appliances, electric energy can be effectively saved. This scheme is generally adopted by large and medium-sized enterprises. This scheme generally requires relatively large investment and requires high technical requirements. Ordinary individuals or small enterprises do not have this ability.

2) It is also an effective method to reduce the long-distance transmission loss. The biggest advantage of this method is that the effect is obvious. Generally, the country adopts this method for large-scale transformation of the power grid, and new power transmission technologies may be adopted. The main disadvantages of this method are the huge cost and wide influence range, and it is not suitable for general energy-saving fields.

Contents of the invention

Aiming at the defects of existing energy-saving methods, the invention proposes an automatic power-off device based on relay technology with low cost and high practicability.

The structure of the device includes a DC power supply module, a power supply control module and a current sampling module, wherein: the DC power supply module is connected to the AC power supply line through a switch, the current sampling module is also connected to the AC power supply line, and the DC power supply module supplies power to the power supply control module. The sampling module provides control signals to the power supply control module, and the power supply control module acts on the switch through the DC power supply module.

The current sampling module samples the current value in the power supply line through a transformer as a control signal.

The power supply control module uses a timer and a relay to control the state of the switch to realize the automatic power-off function.

Technical effect:

The invention integrates the relay technology into the switch device, has simple structure, low cost, high practicability and wide application range. The invention is simple and easy to use, can automatically cut off the circuit after the user turns off the electric appliance, not only effectively saves the standby energy consumption of the household appliance, but also saves time, improves the safety of electricity consumption, and plays a positive role in energy saving and emission reduction.

Description of drawings

Fig. 1 is a structural block diagram of the present invention.

Figure 2 is a circuit schematic diagram of the DC power supply module.

Figure 3 is a schematic circuit diagram of the current sampling module.

Fig. 4 is a schematic circuit diagram of the power supply control module.

Fig. 5 is a working flowchart of the device of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

When the electrical appliance is in the working state (starting moment) and the standby state, the current difference in the circuit is very obvious. The present invention is designed according to this principle. The module structure of the present invention is shown in Figure 1, including a DC power supply module, a power supply control module and a current sampling module, wherein: the DC power supply module is connected to the AC power supply line through a switch, and the current sampling module is also connected to the The DC power supply module supplies power to the power supply control module, the current sampling module provides control signals to the power supply control module, and the power supply control module acts on the switch through the DC power supply module.

The circuit structure of the DC power supply module is shown in Figure 2. This module converts 220V AC power into rated DC power through a transformer and a full-bridge rectifier circuit. The transformer is connected to the AC power supply line through a switch, and the switch is a common switch of the device of the present invention and the AC power supply line. Closing the switch starts the device and also conducts the power supply line.

The circuit structure of the current sampling module is shown in Figure 3, the module includes a transformer L, a rectifier diode D5, two capacitors C3, C4 and a variable resistor W. The transformer L is tightly wound on the main road of the power supply line with thin wires, and the variable resistor W is used to determine the magnitude of the current sampling value.

The circuit structure of the power supply control module is shown in Figure 4. This module includes a triode VT, two resistors R2, R3, three capacitors C5~C7, a diode D6, a timer and a relay J. The timer uses 555 timing device.

If the space of the socket is large enough, the entire device circuit can be arranged in the socket, which is both beautiful and practical.

The work flow of device of the present invention is as shown in Figure 5, and specific content is as follows:

Press the switch to start the device, the DC power supply module provides 12V DC voltage to the device circuit, the transformer L in the current sampling module induces a large voltage at the moment of starting, the sampling current is rectified by the diode D5 and then added to the power supply control module Class b of the triode VT. Under the combined effect of DC voltage (supply voltage) and sampling current, VT is turned on, pin 2 of 555 timer is lower than the trigger level 1/3VDD, 555 timer is set, relay J is pulled in, and the circuit is self-locking and energized ; When the electrical appliance changes from the working state to the standby state, because the voltage induced by the transformer L is small, the discharge tube inside the 555 timer is open, and the capacitor C6 is charged through the resistor R3. When the voltage on C6 is greater than or equal to the threshold level (2/3VDD), the timer resets, the 555 timer pin 3 is low, the relay J is released, and the circuit is disconnected.

When there are household appliances working, because the triode VT is turned on, the 555 timer is always in the trigger delay state, the relay J pulls in, and the circuit continues to supply power; when the appliance is turned off, the device automatically cuts off the power supply within a period of time after the appliance is turned off. Realize automatic power off function.

Claims (5)

1. auto-power-off device is characterized in that:

The structure of this device comprises direct current supply module, power supply control module and current sample module, wherein: the direct current supply module is by switch incoming transport supply line, the current sample module is incoming transport supply line also, the direct current supply module is given the power supply of power supply control module, the current sample module provides control signal for the power supply control module, and the power supply control module acts on switch by the direct current supply module.

2. auto-power-off device according to claim 1 is characterized in that: described direct current supply module is to produce direct current by transformer and full bridge rectifier.

3. auto-power-off device according to claim 1 is characterized in that: described current sample module is by the current value in the mutual inductor sample ac power supply line.

4. auto-power-off device according to claim 1 is characterized in that: described power supply control module is the state by timer and relay control switch.

5. according to claim 1 or 3 described auto-power-off devices, it is characterized in that: adopt variable resistor to determine the size of current sampling data in the described current sample module.

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