CN104410284A - Small type pyroelectric transformer - Google Patents

Abstract

A small type pyroelectric transformer made of thermoelectric material and pyroelectric material functions in boosting alternating current. According to the arrangement, the thermoelectric material serves as an electricity-heat converting unit, the thermoelectric material serves as a heat-electricity converting unit, and through an electric heating-thermoelectric coupling mechanism, the alternating current is input to lead to constantly stable high-voltage alternating current output; after rectifying, stabilizing and filtering, direct current voltage is acquired, and accordingly a direct current voltage power supply function is achieved.

Description

A small pyroelectric transformer

technical field

The invention belongs to the field of electrical technology, and in particular relates to the field of a small voltage transformer.

Background technique

Voltage transformer is a device for changing AC voltage, which is widely used in electrical equipment and wireless circuits. Divided according to the working principle of the voltage transformer, the existing transformers can be divided into two categories: one is the well-known electromagnetic transformer based on the electromagnetic induction principle of electric-magnetic conversion and magnetic-electric conversion coupling, with wide operating frequency and high efficiency. , but there is electromagnetic interference and noise; the other is the piezoelectric transformer developed in the past 30 years based on the piezoelectric material-based electrical-mechanical conversion and electro-mechanical conversion coupling, which has high conversion efficiency and no electromagnetic radiation, but It can only work in the resonant state, and the working frequency is determined by the size of the device, so the working frequency band is narrow.

Contents of the invention

The object of the present invention is to provide a pyroelectric transformer different from conventional electromagnetic transformers and piezoelectric transformers.

The technical solution adopted by the present invention to solve the technical problem is: provide a small pyroelectric transformer device, which is composed of an electric-thermal conversion unit and a thermal-electric conversion unit; the electric-thermal conversion unit is made of thermoelectric materials. The thermal-electric conversion unit is made of pyroelectric material; the electrical-thermal conversion unit and the thermal-electric conversion unit are fixedly connected, and the connected materials can be bonded with thermally conductive adhesive.

In the present invention, the electric-thermal conversion unit is used as the output terminal of the voltage. When a voltage is input to the electric-thermal conversion unit, the temperature of the electric-thermal conversion unit changes due to the Peltier effect of the thermoelectric material. After the heat energy is exchanged, the temperature of the thermo-electric conversion unit changes accordingly, and the thermo-electric conversion unit becomes the output end of the voltage due to the pyroelectric effect of the pyroelectric material and outputs a certain voltage. In the present invention, a periodic alternating voltage is input to the electrothermal conversion unit as the input terminal, and as the voltage changes periodically, the electrothermal conversion unit undergoes periodic temperature rise-decrease changes, corresponding to The connected thermo-electric conversion unit also undergoes periodic temperature rise-decrease changes, so that the thermo-electric conversion unit outputs a periodic alternating voltage. In the present invention, the thermoelectric material of the electric-thermal conversion unit is a semiconductor and has a lower impedance, and the pyroelectric material of the thermo-electric conversion unit is an insulator or a quasi-insulator and has a higher impedance, so a When the voltage is lower, a higher voltage is obtained at the output, so as to realize the voltage boosting effect.

Beneficial effect

1. The present invention is a new type of transformer based on the electric-thermal energy conversion mechanism of thermoelectric materials and the thermal-electric energy conversion mechanism of pyroelectric materials, and does not produce noise and electromagnetic energy conversion caused by mechanical vibration in traditional transformers during operation Caused by electromagnetic radiation and other problems.

2. The thermoelectric material in the present invention has dual characteristics of heating and cooling when AC is input, and within a relatively large frequency range, it can ensure that the system is always in a safe temperature range without additional heat dissipation devices.

3. The pyroelectric material in the present invention responds sensitively to temperature changes, and the heat generated in the system is accumulative, that is, the continuous increase or decrease of heat within a period of time will be realized as a change in temperature, so the working frequency band of the present invention Wide, especially able to work at very low frequencies (0.1Hz).

4. The present invention has a compact structure, greatly reduces the complexity of the device, and easily realizes miniaturization and cost reduction of the device.

5. The present invention can be freely connected in series and parallel as individual units, has high customizability and flexibility, and can meet the power consumption demands of various electrical appliances.

Attached content

Fig. 1 is a schematic structural diagram of a small pyroelectric transformer of the present invention.

Fig. 2 is an equivalent circuit diagram of the small pyroelectric transformer of the present invention.

Fig. 3 is a schematic diagram of the electricity-to-heat conversion of the thermoelectric material in the present invention, and Fig. 3(a) and Fig. 3(b) respectively correspond to the diagram of the electricity-to-heat conversion of the thermoelectric material after inputting voltages of opposite polarities.

Fig. 4 is a schematic diagram of thermo-electric conversion of the pyroelectric material in the present invention.

Fig. 5 is a graph showing the voltage input and output characteristics of the small pyroelectric transformer of the present invention.

Fig. 6 is a schematic diagram of the interface circuit of the small pyroelectric transformer of the present invention.

Detailed ways

The present invention is different from the two existing transformers in the background technology. The transformer realizes the voltage transformation based on the coupling between the electric-thermal conversion of the thermoelectric material and the thermal-electric conversion of the pyroelectric material, which is referred to herein as Pyroelectric transformer. Compared with the electromagnetic transformer, the present invention can significantly reduce the volume of the device under the condition of realizing a very high transformation ratio, and does not generate noise and electromagnetic radiation; compared with the electromagnetic transformer and the piezoelectric transformer, the present invention has a wider working frequency band , can work at a lower frequency (0.1Hz).

The invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention utilizes the heating/cooling characteristics of thermoelectric materials in the case of electrification, and the pyroelectric characteristics of pyroelectric materials in the process of heating or cooling, and converts low-voltage AC input into high-voltage through electrothermal-thermoelectric coupling. A small pyroelectric transformer with AC output.

The specific implementation is as follows:

As shown in Figure 1, the present invention provides a small pyroelectric transformer, which is composed of an electric-thermal conversion unit and a thermal-electric conversion unit; the electric-thermal conversion unit is made of thermoelectric material as the main material, The thermal-electric conversion unit is made of pyroelectric material as the main material; the thermoelectric material is a semiconductor thermoelectric material with a large pyroelectric effect; the pyroelectric material is a piezoelectric ceramic with a large pyroelectric coefficient or piezoelectric single crystals. The electric-thermal conversion unit and the thermal-electric conversion unit are fixedly connected by thermally conductive glue; in a single device, there are two thermal-electric conversion units, which are respectively attached to the electrothermal conversion unit. Cold and hot surfaces.

As shown in Figure 2, the electric-thermal conversion unit in the present invention converts the input electric energy into thermal energy, and through heat conduction, it reaches the thermal-electric conversion unit quickly, and the thermal-electric conversion unit converts thermal energy into electrical energy output; due to the thermal-electric conversion The equivalent impedance R2 of the unit is much greater than the equivalent impedance R1 of the electro-thermal conversion unit, according to the law of power conservation in the circuit (where V _i represents the input voltage, V _o represents the output voltage, and η represents the conversion efficiency), as long as the conversion efficiency η is not lower than a certain value, the device can output several times, tens of times or even hundreds of times higher than the input voltage voltage.

As shown in Figure 3(a), the electro-thermal conversion unit in the present invention is mainly made of N-type and P-type thermoelectric materials. If it flows from end A to end B, the temperature at end B will increase and the temperature at end A will decrease. At this time, end A is the cooling end and end B is the heating end; if the electric-thermal conversion unit is applied with The voltage with the opposite polarity in Figure 3(a), the situation is as shown in Figure 3(b), the free electrons flow from the B terminal to the A terminal, the temperature of the B terminal decreases and the temperature of the A terminal increases, and at this time the A terminal is heating Terminal B is the cooling terminal; when alternating current is applied to the electrothermal conversion unit, the heating terminal and the cooling terminal are periodically switched.

As shown in Figure 4, when the pyroelectric material of the thermo-electric conversion unit is heated or cooled, a pyroelectric current is generated on the circuit and a voltage is generated across the load.

The voltage input and output characteristics of the present invention are shown in Figure 5. Assuming that the input voltage is an ideal AC square wave, the ideal curve that can cause the temperature change of the electric-thermal conversion unit and the thermal-electric conversion unit is a triangular wave. In practice, due to the existence of heat in the device Scattering and other problems make the temperature change have a certain deviation. The actual temperature curve represented by the dotted line in Figure 5 is only a possible model in a simple case, but the overall change trend is stable and regular; The ideal output voltage waveform should be an AC square wave, but due to the heat scattering of the device and the possible phase change of the pyroelectric material, the actual voltage presents a sinusoidal waveform.

There can be multiple devices provided by the present invention, and multiple devices can be connected in series and parallel to increase the boost ratio and output power; the present invention can also perform voltage rectification, voltage stabilization, and filtering through the interface circuit, thereby realizing The function of a small DC high voltage power supply.

The above-mentioned thermoelectric materials of the present invention use semiconductor thermoelectric materials with large pyroelectric effect, or other materials and specifications can be selected according to actual needs; pyroelectric materials use piezoelectric ceramics or piezoelectric cells with large pyroelectric coefficients. Crystal, or other materials and specifications can be selected according to actual needs.

The energy efficiency of the present invention depends on the thermoelectric coefficient of the thermoelectric material, the pyroelectric coefficient of the pyroelectric material and the coupling coefficient of the two.

Claims (6)

1. a low profile thermal releases piezoelectric transformer, it is characterized in that: described device is made up of electricity-hot-cast socket unit and heat-electric converting unit, electricity-hot-cast socket unit is voltage input end, the voltage output end of heat-electric converting unit, is fixedly connected with between electricity-hot-cast socket unit and heat-electric converting unit; In said device, two heat-electric converting units depend on pyrogenicity end and the refrigeration end of electricity-hot-cast socket unit respectively, the voltage that output polarity is contrary.

2. a kind of low profile thermal according to claim 1 releases piezoelectric transformer, it is characterized in that: the main component of described electricity-hot-cast socket unit is thermoelectric material; The main component of described heat-electric converting unit is pyroelectricity material.

3. a kind of low profile thermal according to claim 1 releases piezoelectric transformer, it is characterized in that: described thermoelectric material uses the semi-conductor thermoelectric material having larger thermoelectric effect; Described pyroelectricity material uses the piezoelectric ceramic or piezoelectric monocrystal that have compared with big pyroelectric coefficient.

4. a kind of low profile thermal according to claim 1 releases piezoelectric transformer, it is characterized in that: fixing by heat-conducting glue bonding between described electricity-hot-cast socket unit and heat-electric converting unit.

5. a kind of low profile thermal according to claim 1 releases piezoelectric transformer, it is characterized in that: this device connection in series-parallel being more than or equal to 2 connected, obtain suitable current and voltage, thus meet different needs for electricity.

6. a kind of low profile thermal according to claim 1 releases piezoelectric transformer, it is characterized in that: the high voltage that this device exports is crossed interface circuit and completed the step such as rectification, voltage stabilizing, filtering of voltage and export high direct voltage.