Motorised optical turnstile gates are an upgraded form of the turnstile gates. An upgrade is the key to cost saving, hardware upgrade, software upgrade or firmware upgrade. Upgrade does not mean replacement but to improve the performance and compliances with latest gares available. Turnstile gate suppliers have been trying their best to offer world class products right from the inception, and from a technical point of view three major components of the turnstile electronic motherboard, electric motor or solenoid mechanism and outer body. Each component is precisely chosen to form the best product to cater the access control market needs. But as a rule of thumb, nothing is permanent. There is a huge transition in technology for turnstile gates from electromechanical to motorised and all in between, so the turnstile gate suppliers need to be updated with latest technical innovations to provide the best to market.
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Semi automatic & motorised tripod turnstile gate
As the name indicates, the turnstile operates using the three arms in the form of the tripod. As whole the unit is made of metal in all forms, be it SUS304 grade steel or mild steel (MS) depending on the application, the earliest units supplied were the electro mechanical mechanism or referred to as semi automatic tripod turnstile gates. In semi-automatic tripod turnstiles, the arm is activated & needs to be pushed physically by the pedestrian to ensure the entry or exit to or from premisis. The units are now available as an upgraded version referred to as motorised or fully automatic tripod turnstile. The arms are operated automatically by the motor and allows the pedestrian to enter or leave the site, the motor used can be servo, brushless DC motor or Brushed DC motor. The option to upgrade must exist in the existing unit at the site and it is solely the discretion of turnstile gate suppliers if they have kept this option as a feature or the turnstile gate needs to be replaced by the totally new model.
Upgrading of motors in turnstile gates
The motors play a very crucial role in turnstile gate systems. And the type of motor used has a serious impact on the cost as well as performance of the system. At early stages the brushed motors were used. The speed of the brushed DC motors can be varied by changing the operating voltage or the strength of the magnetic field, and based on the connections, speed & torque can be altered. But the brushed DC motors are subject to wear and tear at a very high level, hence noise level increases and the replacement of the motor becomes inevitable. To overcome issues of wear & tear, the brushless motors have been introduced. The BLDC uses an electronic controller to switch DC currents to the motor windings for the production of the magnetic fields that helps in effective rotation in space. The control system used in the BLDC is an alternative to the brushes used by the brushed motor. Servo motors are the best ever choice used in the turnstile gates. The servo motor uses the rotary encoder or a potentiometer to form a servomechanism. The main characteristics of the servomotor is precision.
| DESCRIPTION | BRUSHED | BRUSHLESS | SERVO |
| Life | Short (wear due to brushes) | Long (no wear out) | No wear at all |
| Speed | Medium | High | Highest with precision |
| Accelration | Medium | High | High with control |
| Efficeincy | Medium | High | Highest |
| Noise | High | Quiet | No noise |
| Cost | Low | Medium | High |
IR sensors used for optical turnstile gates
Optical turnstile gates are characterised by presence of the sensors ranging from one pair to several pairs and each pair has the unique application and use. The IR sensors are located at different coordinates of the optical turnstile gates. The number of sensors are determined by the application and quantity is decided on the basis of the control boards used. The control board must & should have the capability to add extra sensors, in general three pairs are used and can be upgraded to nine pairs. Each pair of sensors is a unique choice for application in optical turnstiles like flap optical turnstile or speed gates etc. The brief description of few sensors in optical turnstiles are as below
| Anti Tailgating sensor | In motorised optical turnstile gates, this sensor helps in preventing the tail gating or piggybacking of the pedestrians. This way the illegal intrusion is halted. |
| Anti Pinching sensor | This sensor in optical turnstile gates prevents the accidental winding up of the flaps or wings of the turnstile. If the sensor discovers any obstacle in the passage, it prevents the flaps or wings from moving further up. Thus, it prevents possible injuries to pedestrians. |
| Waist high sensor | These sensors are located at the waist height of the optical turnstile gates, it is possible for moving arms to create fast, double activations. |
| Anti Pass back sensor | These sensors help in disallowing the cross transfer of the pedestrians in the passage of the optical gates. |
The sensors can be upgraded in case of the optical gate turnstiles on the basis of the project requirements to provide the existing logical control board feature for upgradation.
Flaps or wings of the optical turnstile gates
In general the wings are made of acrylic, and are provided with different colors- black, red, green, blue, transparent or translucent. The wings are either of standard width coverage dimensions (~250mm) or ADA compliant (~450mm) each wing. Some wings are retractable to cover the lane width partially for ADA compliance. The wings for the optical turnstile gates can be upgraded from color, thickness and compliance point of view, but the wing dimensions contribute to the weight of the wing hence the specifications of the motor need to be verified before any upgrade. The wings can be changed to tampered glass of thickness varying from 8 to 10mm thickness. In all cases, the reliable operation of the gate is important, regardless of the wing type in terms of material, color and thickness. All dynamics and aesthetics must comply with the project requirement. The reflective LED lights are also incorporated in the wings to look much prettier.
Requirements for Outdoor application of turnstile gates
Majority of the motorised optical turnstile gates are designed & developed for indoor application barring few like waist height & full height turnstiles. The waist & full height turnstiles are made of all metal but ingress protection is limited to IP55 unless specified. The material generally used is stainless steel of grade SUS304 but that does not make it perfect for outdoor application where resistance to harsh environmental conditions is the order of day, be it high temperature or dust or moisture due to humidity. In such cases the units are made of mild steel with powder coating or deep galvanised to resist the environmental harshness. In the process of hot dip galvanisation (HDG), iron, steel or ferrous materials are coated with a layer of zinc by passing the metal through molten zinc at a high temperature of 460°C (860°F) to form zinc carbonate. The zinc carbonate helps in preventing the material from corrosion by providing a very tough resistance to harsh environments. The powder coating can also be used to make turnstiles suitable for outdoor application, the dry powder is applied through the electrostatic process on the turnstile steel surface. Powder coating protects the turnstiles and provides durable finish, and the mirror polishing should not be confused with powder coating. Hot dip galvanisation is advantageous compared to powder coating.
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