The present invention discloses a relay zero-crossing on and off control method and a relay zero-crossing on and off control system. The method includes the steps as follows: detecting the zero time t0 of the zero voltage phase of a relay when receiving the relay on and off control instruction; calculating out the time between two adjacent moments of the voltage phase zero-crossing of the relay, namely zero period T, according to the acquired fixed relay time t1 and the power frequency f of the relay; performing further calculation to acquire the dynamic delay time t2; and finally controlling the front end of the relay to connect or disconnect at the dynamic delay time t2 after the zero time t0, and controlling the rear end of the relay to automatically connect or disconnect at the fixed delay time t1 after the front end of the relay connects or disconnects so that the rear end of the relay connects or disconnects at the next zero time after zero time detection, and therefore the surge current and arc discharge are avoided so that the impact to the power grid is avoided, and the service life of the relay is prolonged.

Relay zero-crossing on and off control method and relay zero-crossing on and off control system

The invention discloses a control device for switching on and switching off a relay and an air conditioner. The control device for switching on and switching off the relay comprises a control unit, a power supply and a relay, wherein the power supply is electrically connected with the relay; a zero-cross detection circuit is connected in parallel between the power supply and the relay and is used for detecting a zero-cross signal of the power supply and transmitting the zero-cross signal to the control unit; the control unit is connected with the signal input end of the relay and is used for switching on or switching off the relay according to the zero-cross signal. According to the control device for switching on and switching off the relay, the zero-cross signal is detected; the relay matched with inductive load is controlled when the power supply cross the zero point, so that the peak voltage generated when the relay is switched on and off can be greatly reduced; meanwhile, according to the control device, a resistance-capacitance absorbing circuit can also be omitted; the miniaturization of a computer board can be facilitated; the cost can be lowered.

Control device for switching on and switching off relay and air conditioner

The invention provides a method of protecting a relay and a system thereof. The method comprises the following steps of recording relay closing time T1 and relay disconnection time T2 in advance; when an operation instruction is relay closing and after a zero signal sent by a first optical coupler is detected, delaying time of subtracting the T1 from a current power grid period and then sending a closing signal to a relay module; when the operation instruction is relay disconnection and after a zero signal sent by a second optical coupler is detected, delaying time of subtracting the T2 from the current power grid period and then sending a disconnection signal to the relay module. Therefore, at the moment of relay closing/disconnection, the relay is at zero point time of electric supply. An impact current on the relay is minimum so that an effect of protecting the relay is reached and the service life of the relay is prolonged.

Method of protecting relay and system thereof

A control apparatus for a relay and controlling method thereof. The controlling method includes: detecting an input voltage of the relay and a current flowing through the relay; obtaining a voltage zero crossing point information according to the input voltage and a reference voltage value; turning on the relay at an initial turn-on time point according to the voltage zero crossing point information, and obtaining a real turn-on time point of the relay according to the current flowing through the relay; obtaining a turn-on delay of the relay according to the initial turn-on time point and the real turn-on time point, and adjusting the initial turn-on time point to obtain a compensated turn-on time point according to the turn-on delay.

Control apparatus for relay and controlling method thereof

The invention discloses a contact fault monitoring method and a contact fault monitoring device. The method comprises the following steps: through sampling the current or voltage of a contact to be measured, taking the moment, when a sampling signal is received for the first time after a contact pull-in signal is received, as the starting time of the adhesion timing, and taking the moment, when no sampling signal is received, as the finish time of the adhesion timing; when the adhesion timing duration is larger than a preset timing duration, the situation that the loop where the contact to be measured is located is not turned into open-circuit stage when the contact pull-in timing is finished is indicated, that is, the contact to be measured is not automatically shut down along with finish of the pull-in timing of the contact, so that the situation that abnormal adhesion of the contact to be measured occurs can be determined. The contact fault monitoring method and device can monitor the abnormality of contact adhesion, thereby ensuring the accuracy of electrical endurance test and reliable operation of relative equipment.

Contact fault monitoring method and device

The utility model relates to the technical field of electronic circuits. A self-adjusting zero-crossing control circuit for an electromagnetic?relay comprises a relay circuit, a load circuit, a sampling circuit, a control chip circuit and a drive circuit, wherein the sampling circuit comprises an alternating current zero-crossing sampling circuit and a relay disconnection detection circuit; the alternating current zero-crossing sampling circuit carries out zero-crossing detection on alternating current waveforms outputted to the load circuit by the relay circuit; the relay disconnection detection circuit carries out detection on when contacts of the electromagnetic?relay are disconnected; the sampling circuit outputs the zero-crossing signals and the relay state signals to the control chip circuit; and the control chip circuit carries out judgment and processing on the received signals, and then adjusts and outputs relay connection and disconnection signals to the drive circuit for carrying out connection and disconnection control on the relay circuit. The self-adjusting zero-crossing control circuit for the electromagnetic?relay is applicable to self-adjusting zero-crossing disconnection control on the electromagnetic?relay.

Self-adjusting zero-crossing control circuit for electromagnetic?relay

The invention discloses a method for eliminating the adhesion of a relay contact. The method is characterized by sequentially comprising the following steps of: a release step, cutting the working current of a relay, and meeting the release requirement of the relay contact; a release delay step, waiting the relay contact to be transformed from a contact state to a separation state; an adhesion detection step, detecting whether the relay contact is cut as scheduled or not, if not, entering an absorption step; the absorption step, absorbing the relay contact again, and if so, entering a quitting step to close all steps; an absorption delay step, keeping the electrical conditions of all relays after the absorption step; and the release step again. According to the invention, the absorption step and the release step are executed for multiple times so that sufficient rocking times are generated on the relay contact, and thus the structure of the adhered contact is sufficiently destroyed; and the adhesion is eliminated by utilizing the poor fastness of the adhered relay contact on the basis of the original structure of the relay. The method disclosed by the invention has the advantages of simplicity, effectiveness and low cost without other peripherals.

Method for eliminating adhesion of relay contact

The invention relates to a capacitance-type sensor. The inductive device of the capacitance-type sensor comprises an upper cover, a printed circuit board matched with the upper cover, and three metal balls arranged in a cavity formed by the upper cover and the printed circuit board. A first inductive polar plate, a second inductive polar plate and a third inductive polar plate are printed on the upper surface of the printed circuit board through a copper foil. At least three metal pins are welded on the lower surface of the printed circuit board. The three metal pins are respectively connected to the first inductive polar plate, the second inductive polar plate and the third inductive polar plate on the printed circuit board. The three metal balls are made of nonmagnetic metals. The three metal balls respectively correspond to the first inductive polar plate, the second inductive polar plate and the third inductive polar plate in position. The metal balls on both sides are respectively and fixedly clamped in a fixed structure of the upper cover. The metal balls in the middle roll freely along with change of the inclination angle of the printed circuit board.

Inductive device of capacitance-type sensor

The utility relates to an electric iron; in particular to an electric iron with a human induction controller, and the electric iron is characterized in that a human induction controller is arranged inside the electric iron. The electric iron can detect whether the electric iron is used by the user in real time, when the user starts to use the electric iron, the electric iron can induce immediately and start heating; when the user quits hold of the electric iron, the electric iron can also immediately induce, if the electric iron is kept in a flat lying position at same time, then the heating is stopped, to prevent the clothes from being burned out and fire hazard from happening to maximum limit, if the electric iron is kept in a vertical position at same time, then the heating can be stopped after a period of time delaying, therefore the user need not to wait for the electric iron temperature recuperation after the intervals of ironing the clothes, to be convenient for the application of the user, and the electrical energy can be saved simultaneously when the user does not use the electric iron during a long time.

Electronic flat-iron with human body induction controller

The invention relates to a control method for a circuit, in particular to a silicon controlled rectifier triggering control method. The silicon controlled rectifier triggering control method comprises the first step of collecting power source zero signals, the second step of obtaining a power source zero passage period, the third step of working out the prediction time t1 of the next power source zero passage point according to the current power source zero signals collected in the first step and the power source zero passage period obtained in the second step, and subtracting one time initial lead delta t from the prediction time t1 of the next power source zero passage point to obtain the lead triggering time t2, namely t2=t1-delta t, and the fourth step of outputting a silicon controlled rectifier triggering pulse signal at lead triggering time t2 according to the lead triggering time t2 obtained in the third step. The silicon controlled rectifier triggering control method can be used in a silicon controlled rectifier triggering control circuit and can solve the problem that due to inconsistency of silicon controlled rectifier conduction and a power source zero point and the zero point phase deviation, a load interferes with a harmonic wave, conduction and Click of a power grid.

Wei Su

Papers

Self-adjusting zero-crossing control circuit for electromagnetic?relay

Method for eliminating adhesion of relay contact

Inductive device of capacitance-type sensor

Electronic flat-iron with human body induction controller

Silicon controlled rectifier triggering control method