A relay is an electronic control device that has a control system (also called an input loop) and a controlled system (also called an output loop). It is usually used in automatic control circuits. It actually uses a smaller current to control a larger An “automatic switch” of electric current. Therefore, it plays the roles of automatic adjustment, safety protection, and conversion circuit in the circuit.
Electromagnetic relays are generally composed of iron core, coil, armature, contact reed, etc. As long as a certain voltage is applied to both ends of the coil, a certain current will flow through the coil, thereby producing an electromagnetic effect. Under the action of electromagnetic attraction, the armature will overcome the pulling force of the return spring and be attracted to the iron core, thereby driving the armature to The moving contact and the static contact (normally open contact) are closed. When the coil is powered off, the electromagnetic attraction also disappears, and the armature will return to its original position under the reaction force of the spring, causing the movable contact to attract the original static contact (normally closed contact). In this way, it is attracted and released to achieve the purpose of conducting and cutting off in the circuit. For the “normally open and normally closed” contacts of the relay, they can be distinguished as follows: the static contact in the disconnected state when the relay coil is not energized is called the “normally open contact”; the static contact in the connected state is called It is a “normally closed contact”.
When the relay module is working, the electromagnet is energized and the armature is sucked down to make D and E contact, and the working circuit is closed. When the electromagnet is powered off, it loses its magnetism, and the spring pulls up the armature, cutting off the working circuit. Therefore, the relay module is a switch that uses electromagnets to control the on and off of the working circuit.
The benefits of using relay modules to control circuits: use low voltage to control high voltage; remote control; automatic control. The relay module is an automated electrical switch that relies on electromagnetic induction.
Relay modules are widely used in fields such as remote control, telemetry, communications, automatic control, mechatronics and aerospace technology to control, protect, regulate and transmit information.
ZHT0800 is an 8-channel relay control module that provides 8 channels of DO and 1 channel of RS485 interfaces. It supports the standard Modbus RTU protocol and delays closing after the relay is turned on. It is simple and convenient to use, provides complete technical support, and can be widely used in various types of applications. Application scenarios of switching output.
