CN-224203298-U - Low-power consumption zero crossing detection circuit

CN224203298UCN 224203298 UCN224203298 UCN 224203298UCN-224203298-U

Abstract

The utility model provides a low-power consumption zero-crossing detection circuit, which relates to the technical field of electronic circuits and comprises an X-capacitor energy bleeder circuit, a voltage reduction circuit, a half-wave detection circuit and an optocoupler driving circuit, wherein the X-capacitor energy bleeder circuit bleeds energy stored on an X-capacitor and adjusts bleeder time, the X-capacitor energy bleeder circuit is used as a signal input and a power supply of the half-wave detection circuit, the voltage reduction circuit converts high-voltage alternating current into low-voltage direct current to provide power for an optocoupler primary stage, the half-wave detection circuit outputs a pulse signal when an alternating current voltage crosses zero point and is used as an input source of the optocoupler driving signal, and the optocoupler driving circuit converts the detected pulse signal into an isolated zero-crossing signal and transmits the isolated zero-crossing signal to an MCU. The utility model can reduce the power consumption of the electronic equipment in a standby state, save unnecessary energy consumption, improve the safety, avoid bad electric shock results, reduce the extra cost, use the conventional grade insulating material, and simultaneously improve the service life of components such as an optical coupler and the like.

Inventors

CHEN ZHAOXIANG
Su Jieyang

Assignees

厦门盈趣科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20250401

Claims (8)

1. The low-power consumption zero-crossing detection circuit is characterized by comprising an X capacitance energy bleeder circuit, a voltage reducing circuit, a half-wave detection circuit and an optocoupler driving circuit; The X capacitor energy discharging circuit comprises an X capacitor, a discharging resistor and a special X capacitor automatic discharging integrated chip, wherein the X capacitor energy discharging circuit is used for discharging energy stored on the X capacitor, adjusting discharging time and being used as a signal input and a power supply of a half-wave detection circuit; The step-down circuit comprises a resistance-capacitance step-down network, a second rectifying circuit, a second filter capacitor and a second voltage stabilizing diode, and is used for converting high-voltage alternating current into low-voltage direct current and providing power for the primary of the optocoupler; The half-wave detection circuit comprises an energy storage capacitor, a first rectifying circuit, a first filter capacitor, a first zener diode and a direction indicator, wherein the half-wave detection circuit is used for outputting a pulse signal when an alternating voltage crosses a zero point and is used as an input source of an optocoupler driving signal; The optocoupler driving circuit comprises an MOS tube, a current limiting resistor, an optocoupler and a pull-up resistor, and is used for converting the detected pulse signals into isolated zero crossing signals and transmitting the isolated zero crossing signals to the MCU.
2. The low power consumption zero crossing detection circuit as set forth in claim 1, wherein the dedicated X capacitor auto-discharge integrated chip has an input connected to the X capacitor and an output connected to ground through a bleeder resistor, the bleeder resistor having a resistance configured to adjust the bleeder time.
3. The low-power consumption zero-crossing detection circuit as set forth in claim 2, wherein the resistor-capacitor voltage-reducing network is composed of a resistor and a capacitor connected in parallel, an input terminal is connected to an ac power grid, and an output terminal is sequentially connected to the second rectifying circuit, the second filter capacitor and the second zener diode.
4. The low power consumption zero crossing detection circuit as claimed in claim 3, wherein the second rectifying circuit adopts a half-bridge rectifying structure, and the second filter capacitor is connected in parallel with the second zener diode, and outputs a stable low voltage dc power supply to the optocoupler driving circuit.
5. The low power consumption zero crossing detection circuit as set forth in claim 4, wherein the input end of the energy storage capacitor in the half-wave detection circuit is connected with the output end of the X capacitor energy bleeder circuit, the output end is sequentially connected with the first rectifying circuit, the first filter capacitor and the first voltage stabilizing diode, the first rectifying circuit in the half-wave detection circuit converts the low voltage alternating voltage into pulsating direct voltage, the first filter capacitor filters alternating components in the pulsating direct voltage, the first voltage stabilizing diode is used for protecting the back-stage circuit from overvoltage damage, and the director outputs pulse signals after the zero voltage exceeds a threshold value.
6. The low power consumption zero crossing detection circuit according to claim 5, wherein an input end of the direction device in the half-wave detection circuit is connected with an output end of the first filter capacitor, a pulse signal is generated when the alternating voltage crosses zero, and the optocoupler is driven by the MOS tube.
7. The low power zero crossing detection circuit of claim 6 wherein the direction indicator outputs a pulse signal as the optocoupler drive signal upon detection of an ac voltage zero crossing.
8. The low power consumption zero crossing detection circuit according to claim 6, wherein in the optocoupler driving circuit, a gate electrode of the MOS tube is connected with an output end of the direction indicator, a source electrode is connected with a primary side of the optocoupler through a current limiting resistor, a drain electrode is grounded, a secondary side of the optocoupler is connected with a power supply through a pull-up resistor, and an output end generates an isolation pulse signal synchronous with zero crossing of the alternating voltage.

Description

Low-power consumption zero crossing detection circuit Technical Field The utility model relates to the technical field of electronic circuits, in particular to a low-power consumption zero-crossing detection circuit. Background The existing zero-crossing detection circuit is usually formed by directly contacting a diode or a triode with a high-voltage power grid, and also adopts an optocoupler to directly contact with the high-voltage power grid as a high-voltage and low-voltage isolation element, however, the existing system has the following problems: 1. The standby power consumption is high, a loop is formed between the current re-circuits, the standby power consumption is increased, and the environment-friendly concept requirement is not met. 2. The safety is insufficient, the additional cost is high, the diode or the triode is directly used as a zero-crossing detection circuit, the circuit is designed as a non-isolated circuit, electric shock injury is easy to occur, and meanwhile, the requirement on the insulation level of a human body contact part is high, so that the additional cost is increased. 3. The device has short service life, namely the optocoupler is directly contacted with a high-voltage power grid to serve as a high-voltage and low-voltage isolation element, and the service life of the optocoupler is shortened due to the changed power grid voltage. Therefore, developing a zero-crossing detection circuit that is efficient, safe, and low in standby power consumption is an urgent need in the industry. Disclosure of utility model In view of the above, in order to solve the problems of high standby power consumption, insufficient safety and short service life of the components of the existing zero-crossing detection circuit, the utility model aims to provide a low-power consumption zero-crossing detection circuit which can reduce the power consumption of electronic equipment in a standby state, save unnecessary energy consumption, improve the safety, avoid the bad consequences of electric shock, reduce the additional cost, use conventional grade insulating materials and simultaneously improve the service life of the components such as an optical coupler. In order to achieve the above purpose, the present utility model provides the following technical solutions: Based on the above purpose, the utility model provides a low-power consumption zero-crossing detection circuit, which comprises an X capacitance energy bleeder circuit, a voltage reducing circuit, a half-wave detection circuit and an optocoupler driving circuit; The X capacitor energy discharging circuit comprises an X capacitor, a discharging resistor and a special X capacitor automatic discharging integrated chip, wherein the X capacitor energy discharging circuit is used for discharging energy stored on the X capacitor, adjusting discharging time and being used as a signal input and a power supply of a half-wave detection circuit; The step-down circuit comprises a resistance-capacitance step-down network, a second rectifying circuit, a second filter capacitor and a second voltage stabilizing diode, and is used for converting high-voltage alternating current into low-voltage direct current and providing power for the primary of the optocoupler; The half-wave detection circuit comprises an energy storage capacitor, a first rectifying circuit, a first filter capacitor, a first zener diode and a direction indicator, wherein the half-wave detection circuit is used for outputting a pulse signal when an alternating voltage crosses a zero point and is used as an input source of an optocoupler driving signal; The optocoupler driving circuit comprises an MOS tube, a current limiting resistor, an optocoupler and a pull-up resistor, and is used for converting the detected pulse signals into isolated zero crossing signals and transmitting the isolated zero crossing signals to the MCU. As a further scheme of the invention, the input end of the special X capacitor automatic discharging integrated chip is connected with the X capacitor, the output end of the special X capacitor automatic discharging integrated chip is grounded through the discharging resistor and is used for rapidly discharging energy on the X capacitor, and the resistance value of the discharging resistor is configured to adjust the discharging time so as to ensure the maintenance of the energy required by the normal operation of the half-wave detection circuit. As a further scheme of the invention, the resistance-capacitance voltage reduction network is formed by connecting a resistor and a capacitor in parallel, the input end of the resistance-capacitance voltage reduction network is connected with an alternating current power grid, the output end of the resistance-capacitance voltage reduction network is sequentially connected with a second rectifying circuit, a second filter capacitor and a second voltage stabilizing diode, the resistance-capacitance voltage reduction network c