Working principle of safety relay function of safe

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Safety relay is an electronic control device, which has control system (also known as input circuit) and controlled system (also known as output circuit). It is usually used in automatic control circuit. In fact, it is an "automatic switch" that uses a small current to control a large current

safety relay, as the name suggests, is a relay that can make regular actions in the event of a safety accident, which is called a safety relay, rather than a relay that will not cause a safety accident. It is mainly composed of relays and circuits. It has a forced guide contact structure, which can ensure safety in case of contact fusion. The following editor will introduce the working principle of safety relay and the function of safety relay

working principle of safety relay

safety relay is 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, resulting in electromagnetic effect. The armature will overcome the tension of the return spring and attract to the iron core under the action of electromagnetic force, so as to drive the dynamic contact and static contact (normally open contact) of the armature to engage. When the coil is powered off, the electromagnetic suction also disappears, and the armature will return to the original position under the reaction force of the spring, making the moving contact and the original static contact (normally closed contact) attract. In this way, the connection and disconnection in the circuit are achieved. For relay “ Normally open, normally closed ” Contacts can be distinguished in this way: static contacts in the disconnected state when the relay coil is not energized are called “ Normally open contact ”; The static contact in the on state is called “ Normally closed contact &rdquo

technical parameters of main products of relay

1. Rated working voltage

refers to the voltage required by the coil when the relay works normally. Depending on the relay model, it can be AC voltage or DC voltage

2. DC resistance (coil impedance)

refers to the DC resistance of the coil in the relay, which can be measured by a universal meter

3. Pull in current

refers to the minimum current that the relay can generate pull in action. In normal use, the given current must be slightly greater than the pull in current, so that the relay can work stably. Generally, the working voltage applied to the coil should not exceed 1.5 times the rated working voltage, otherwise a large current will be generated and the coil will be burned

4. Release current

refers to the maximum current that the relay generates release action. When the current in the on state of the relay decreases to a certain extent, the relay will return to the non energized release state. At this time, the current is far less than the pull in current

5. Contact switching voltage and current (contact capacity)

refers to the voltage and current allowed to be loaded by the relay. It determines the size of the voltage and current that the relay can control. When used, it cannot exceed this value, otherwise it is easy to damage the contact of the relay

function of safety relay

1. Expand the control range. For example, when the control signal of multi contact relay reaches a certain value, it can change, disconnect and connect multiple circuits at the same time according to different forms of contact groups

2. Zoom in. For example, sensitive relays, intermediate relays, etc. can control circuits with a large power with a very small control quantity

3. Integrated signal. For example, when multiple control signals are input into the multi winding relay in the specified form, the predetermined control effect can be achieved through comparison and synthesis

4. Automatic, remote control, monitoring. For example, the relay on the automatic device, together with other electrical appliances, can form a program control circuit to realize automatic operation

editor's summary: that's all for the working principle and function of safety relay. I hope it will be helpful to you. If you want to know more, you can pay attention to information




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