Traditional Culture Encyclopedia - Hotel reservation - What is the installation method of hotel lock?

What is the installation method of hotel lock?

Hello, as far as I know, there is a 555 integrated block control relay on the circuit board. Its working principle is: when inserting the card, press the microswitch to make the 555 integrated block work, control the thyristor, turn on the relay, and make the phase line conduct through the contact of the relay to supply power to the room. When the card is taken out, the 555 integrated circuit continues to control the circuit. After a certain delay, the 555 integrated circuit does not output voltage, turning off the thyristor, making the relay lose power, thus disconnecting the power supply of the room.