Turnstiles are much popular today, widely used in the passage ways which require access control system, we can easily see them in the airport, metro station, train station, office building etc.. Do you know how does turnstile works ? Take card reader as an example, we will make a simple introduction as below. 

1. To connect the power supply AC220V , the system will enter the working state in about 2-3 seconds.

2. When the Card Reader reads a card, it will try to reach the information from the card ,then send the information to the control unit to judge if the information is valid or not. 

3. When the control unit receive the signal/information from the card reader, it will process and judge the information. If the information is valid, the buzzer assembled in the turnstile will make a sound to remind pedestrians that the card is valid, and the control unit will also send a signal to the driving part simultaneously, to make the passage way open and let pedestrians go through .

4. During the time that pedestrians passing through the turnstile, the safety beam/infrared sensor assembled in turnstile body with different height will be triggered, and communicated with the control unit, to make sure the passage way will be open all the time until the people go through the turnstile totally .

5. If the pedestrian forget to use the card or use an invalid card to the turnstile, the system will prohibit pedestrians from passing, and will give an alarm (like a voice : invalid card and illegal entry). 

Note: 

1. Card reader in the part above is only one type of the access control system, we can also use other access control like Biometric reader (Face recognition, 

Fingerprint reader, Iris Recognition), mobile access etc..

2. To the working principle above, it could be workable to all kinds of turnstiles like tripod turnstile, wing gate turnstile, swing gate turnstile, sliding gate turnstile etc..