Composite energy collection circuit

Abstract

The invention discloses a composite energy collection circuit. The composite energy collection circuit is characterized by including a temperature difference power generation sheet, a piezoelectric sheet, a positive-negative peak detection module, a zero potential switching module, a first inductor, a first diode, a first energy storage capacitor, a second energy storage capacitor and a load; thecomposite energy collection circuit has the advantages that the first inductor is in serial connection with a parasitic capacitor in the piezoelectric sheet and the first energy storage capacitor, inthis way, LC oscillation is generated, charges accumulated on the parasitic capacitor in the piezoelectric sheet and the first energy storage capacitor are transferred to the first inductor, at the moment when currents on the first inductor reach the maximum, through the positive-negative peak detection module, a first PNP transistor or a second PNP transistor is immediately disconnected, and thenall energy stored in the first inductor flows to the load and the second energy storage capacitor through the first diode. The whole composite energy collection circuit is a completely self-startingand self-powered circuit and can continually collect temperature difference electric energy and piezoelectric vibrational energy in a current environment, therefore, the energy collection efficiency of the whole composite energy collection circuit is improved, and the application cost is reduced.

Description

technical field [0001] The invention relates to an energy collection circuit, in particular to a composite energy collection circuit. Background technique [0002] Piezoelectric vibration energy collection is a method of collecting vibration energy in the environment by using the piezoelectric effect of piezoelectric materials. Since the output voltage of the piezoelectric sheet is an AC signal, the general electronic equipment is powered by a DC power supply. Therefore, an interface circuit is needed between the piezoelectric film and the electronic device, and the conversion of AC voltage to DC voltage is realized through the interface circuit, and the conversion efficiency of this interface circuit is as high as possible. The first proposed interface circuit It is a standard energy harvesting circuit, which is composed of a diode bridge rectifier circuit and a filter capacitor. The advantage of this structure is that the circuit is simple, stable and reliable. However, du...

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Problems solved by technology

[0002] Piezoelectric vibration energy collection is a method of collecting vibration energy in the environment by using the piezoelectric effect of piezoelectric materials. Since the output voltage of the piezoelectric sheet is an AC signal, the general electronic equipment is powered by a DC power supply. Therefore, an interface circuit is needed between the piezoelectric film and the electronic device, and the conversion of AC voltage to DC voltage is realized through the interface circuit, and the conversion efficiency of this interface circuit is as high as possible. The first proposed interface circuit It is a standard energy harvesting circuit, which is composed of a diode bridge rectifier circuit and a filter capacitor. The advantage of this structure is that the circuit is simple, stable and reliable. However, due to the loss of the threshold voltage of the diode, the acquisition efficiency of the circuit is low, and this The acquisition efficiency of the structure is easily affected by the size of the load

[0003] The thermoelectric power generation chip can use the temperature difference in the environment to collect energy, but usually the temperature difference in the environment is small, the open circuit voltage of the thermoelectric power generation chip is very low, and factors such as the efficiency of the energy harvesting circuit between the power generation chip and the load increase the temperature difference energy. Difficulty in utilization; current thermoelectric energy collection circuits are mainly divided into capacitive charge pump circuits and inductive boost circuits. Although the charge pump circuit can increase the voltage of the thermoelectric power generation chip, the drive capability of the charge pump structure is very weak, and the low-voltage charge pump The circuit is even more inefficient; although the inductive boost circuit has high efficiency and strong ability to drive the load, the open circuit voltage of the general thermoelectric generator is lower than the threshold voltage of the switch tube, which leads to the inductive boost circuit often An external power supply is required, and it cannot start automatically when the external power supply is not connected, which increases the cost of use

[0004] In order to obtain more energy from the environment and increase the total power of environmental energy collection, some researchers have proposed the idea of ​​multi-source energy collection, that is, to collect various forms of energy such as vibration energy, thermal energy, and microwave radiation in the environment. However, since the signals generated by different energy sources are completely different, different signals cannot be directly coupled together, so the general multi-source energy harvesting system usually adopts the comparison method, that is, by comparing the two energy densities to select the one with the stronger energy. One kind of energy, so another kind of energy cannot be collected, affecting the overall collection efficiency

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