Jännitesyötön

Jännitesyötön, or "voltage-free" in English, refers to a method of controlling electrical devices without the need for direct electrical power being supplied to the control circuit. This technique is commonly used in safety-critical applications where the risk of electrical shock or interference must be minimized. In jännitesyötön systems, the control signal is typically transmitted via mechanical, pneumatic, or other non-electrical means, such as push buttons, switches, or solenoids.

The primary advantage of jännitesyötön is enhanced safety, particularly in environments where electrical hazards are a concern, such as in industrial machinery, medical equipment, or explosive atmospheres. By eliminating the need for electrical power in the control circuit, the risk of electric shock or sparks is significantly reduced. This makes the system compliant with strict safety standards, such as those outlined in the European Union’s ATEX directive for explosive environments.

In practice, jännitesyötön is often implemented using normally open or normally closed contacts in switches or relays. These mechanical contacts physically connect or disconnect the power supply to the device being controlled, allowing for reliable and safe operation. The control signal itself may still be electrical, but it is isolated from the power circuit, ensuring that no current flows through the control components unless the switch is actively engaged.

Jännitesyötön is also used in conjunction with other safety mechanisms, such as emergency stop buttons, where immediate disconnection of power is critical. While this method is highly effective for safety applications, it may introduce additional complexity in system design, particularly in automated or high-speed control scenarios where electrical signals are more convenient. Despite this, its reliability and safety benefits make it a preferred choice in many specialized applications.