The time relay is necessary to control the power circuits of the electric motor and provide protection against short circuits. The device allows you to precisely adjust the response time of devices in accordance with the needs of production.
Based on special microcircuits, you can make a time relay with your own hands. Such devices are applicable in everyday life for adjusting the operating time of the washing machine or when debugging the period of heating food in the microwave.
With the help of a time relay, the programming of switching on or off automation, lighting is carried out, and the operation of machines is also controlled. The electronic device includes a voltage stabilizer, a time setting generator, a control apparatus, an input signal amplifier, a relay element. There are several types of device data.
Modern production implements devices with electromagnetic delay. This type is used when operating on direct current, it performs a delay time for operation in the range from 0.07 to 0.11 sec. If the device is designed to turn off the appliance, then the time can be set within 0.5 - 1.4 seconds.
Relays with pneumatic retardation are available withair damper and cataract. This device is capable of providing a time delay ranging from 0.4 to 180 seconds. In this case, the operation accuracy will be no more than 10% of the indicated setting.
Even a mechanical timing relay is programmable. Therefore, the operation of any kind of device depends on how the technician debugs the trigger mechanism. Anchor types of devices operate on the basis of the action of a spring, the position of which is adjusted depending on the setting. After counting the set time, the device changes the position of the contacts. With the help of an anchor relay, you can change the actuation value in the range from 0.1 to 20 seconds. At the same time, the accuracy of the device operation is approximately the same as that of a relay with pneumatic delay (equal to 10% of the setting).
In modern production, motor time relays are used. They include a gearbox, an AC motor, an electromagnet and copper contacts. If a signal exceeding the setpoint is received at the input of the device, then the electromagnet engages the gearbox with the motor and the contacts are transferred. If a fixed value disappears at the input of the time relay, the electromagnet returns to its original position and disengages the gearbox and motor. The time of the motorized instrument can be adjusted from 10 seconds to 3 hours.
Electronic time relays operate on the principle of an active-capacitive circuit, while being quite reliable and accurate. This is the best solution to the problem!
All time relays are used to delay the implementation of complex protection onsubstations and household switchgear. With the help of such devices, false operation of automation and its alarm is excluded. Thus, high clarity in the operation of the equipment is achieved.
Today, factories and plants use microprocessor devices with a time delay. Each block of such a device is responsible for a separate production line, while not only relays, but also conventional contactors and switches are implemented in the block complex. This approach allows us to simplify the circuit and make it more maintainable.
