How does a safety relay work

The main working principle of the relay is: when the change of the input quantity (excitation quantity) reaches the specified requirements, it is an electrical appliance that makes the controlled quantity change in the electrical output circuit with a predetermined step change. It has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop).

Usually used in the control circuit of automation, it is actually a kind of "automatic switch" that uses a small current to control the operation of a large current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

Relays are automatic switching elements with isolation functions, which are widely used in remote control, telemetry, communication, automatic control, and mechatronics.

and power electronics, which is one of the most important control components.

When the relay is working, the electromagnet is energized, the armature is sucked into contact, and the working circuit is closed. When the electromagnet loses its magnetism when it is de-energized, the spring pulls the armature up and cuts off the working circuit. Therefore, the relay is a switch that uses an electromagnet to control the on/off of the working circuit.

How the timing relay worksA timing relay is a relay in which a certain amount of time must pass through a certain amount of time after the input action signal is added (or removed) to produce a trip (or contact action). An electrical component used on a lower voltage or lower current circuit to turn on or off a circuit with a higher voltage and a higher current. At the same time, the timing relay is also an electrical control device that uses electromagnetic or mechanical principles to achieve delay control.

Relays.

The relay is mainly divided into the coil part and the contact part, when the coil part is energized, it will produce magnetic force, so as to attract the contact part to move, and the contact engagement is equivalent to the switch being turned on.

1. Electromagnetic type.

Electromagnetic relays are generally composed of iron cores, coils, armatures, contact reeds, etc. As long as a certain voltage is added to both ends of the first circle, a certain current will flow through the coil, resulting in an electromagnetic effect, and the armature will overcome the tensile force of the return spring under the action of electromagnetic force attraction to attract the core, thereby driving the dynamic contact (normally open contact) of the armature to engage with the static contact (normally closed contact).

When the coil is de-energized, the electromagnetic attraction disappears, and the armature will return to its original position under the reaction force of the spring, so that the moving contact and the original static contact are released. In this way, it is engaged and released, so as to achieve the purpose of conduction and cutting in the circuit.

2. Heat-sensitive drying.

The spring thermal reed relay is a new type of thermal switch that uses thermal magnetic materials to detect and control temperature. It consists of a temperature-sensing magnetic ring, a constant magnetic ring, a reed switch, a thermally conductive mounting sheet, a plastic substrate and some other accessories.

Thermal reed relays do not use coil excitation, but are driven by the magnetic force generated by the constant magnetic ring. Whether the constant magnetic ring can provide magnetic force to the reed switch is determined by the temperature control characteristics of the thermosensitive magnetic ring.

3. Solid-state type.

The solid-state relay is a four-terminal device with two terminals as the input terminal and the other two terminals as the output terminal, and the intermediate isolation device is used to realize the electrical isolation of the input and output.

First, the principleThe safety relay is a necessary control part of the safety loop, which accepts the safety input, and deterministically outputs the switching signal to the control loop of the equipment through the judgment of the internal loop.

To put it simply, the safety relay is a dual-channel signal type, and the safety relay can only work normally when the signals of both channels are normal; During the working process, as long as any channel signal in the vertical gear is disconnected, the safety relay will stop the output until both channel signals are normal and reset before it can work normally.

Second, the wiring diagram

The environment in which the safety relay is usedThe environmental requirement of the safety relay is that there must be a large enough site, so that it will be safer to use. Therefore, this precautions also need special attention when using, and we must pay attention to this, otherwise it will directly affect the use of safety relays. Confusion.

Make model: Strom Safety Relay.

System: XPSAF5130

The working principle of the safety relay: the safety relay has a forced guide contact structure, which is a necessary control part of the safety loop, which accepts the safety input, and deterministically outputs the switch signal to the control loop of the equipment through the judgment of the internal loop. To put it simply, the safety relay is a dual-channel signal type, and the safety relay can only work normally when the signals of both channels are normal; During the working process, as long as the signal of either channel is disconnected, the safety relay will stop the output until the signal of both channels is normal and reset.

The purpose is to protect the machine operator who is exposed to different levels of hazards.