Float Switches

Float switches are a type of level sensor that integrates a float with inbuilt sensor probes to detect and adjust the liquid levels in various systems and devices. These switches primarily control the operation of pumps, valves, or other electrical devices based on fluid levels. The basic design of a float switch consists of a buoyant float attached to a lever arm or stem. The float is usually made of a low-density material, such as foam or plastic, making the device easily float on the liquid's surface. The lever arm or stem is connected to a switch mechanism or sensor assembly. Due to the versatility, simple design, reliability, and reduced costs of float switches, they are widely used by professionals and DIYers in multiple settings.

Understanding the Working Principle of Float Switches

Float switches operate based on the principle of buoyancy. The liquid's buoyant force causes the integrated float of the switch to rise or fall, depending on the liquid levels. This transition in a liquid level triggers to activate the switch, send alarms to a control system, and turn ON or OFF the float switch by making or breaking the circuit. The float switch type depends on the requirements and applications and might include a magnetic reed switch, solid-state switch, or mechanical switch.

Special Features and Benefits of Float Switches

Float switches offer numerous benefits with their unique features, such as:

• They are reliable, cost-effective, and used in different liquids.
• Simple design with low maintenance needs.
• Different configurations and easy integration.
• Wide operating temperature range with high energy efficiency.
• Resist corrosion and shock and rupture-proof. 
• Automatic pump control, preventing overflow and drying.
• Highly flexible and made of durable materials.

Most Popular Types of Float Switches

There are various float switch types available on the market based on their configurations and designs. The most common ones include:

• Vertical Float Switches: These switches are designed to operate vertically, and the float moves up and down along a vertical stem.
• Horizontal Float Switches: They operate in a horizontal position, and the float moves back and forth along a horizontal stem.
• Miniature Float Switches: These small float switches are suitable for tight spaces or small tanks, such as coffee machines and humidifiers.
• Wide-Angle Float Switch: This type of float switch has a wide-angle pivot, controlling the pump or device over a broader range of liquid levels. 
• Tilt Float Switches: These switches feature tilt configuration and tilt when the liquid level rises or falls, activating the switch.
• Cable Float Switches: These switches use a wire or cable (typically suspended in the liquid) to connect the float to the switch.
• Tethered Float Switches: These switches have a float attached to the end of a flexible tether or cable. The float moves up and down with the liquid level, and the tether pulls or releases a lever to activate the switch.
• Magnetic Float Switches: These switches use a magnet inside the float and a reed switch or Hall effect sensor outside the float chamber. As the float moves with the liquid level, the magnet activates the sensor to open or close the switch.
• Electronic Float Switches: Unlike traditional mechanical float switches, electronic float switches use solid-state sensors or conductive probes to detect liquid levels and trigger the switch electronically. They are often more reliable and have no moving parts.
• Multi-Level Float Switches: These switches comprise multiple floats at different levels on a common shaft or cable. Each float corresponds to a specific liquid level, allowing for control at various points.

Typical Applications of Float Switches

Due to their versatility and effective performance, Float switches are mostly employed in a range of industrial, commercial, and residential environments. They are found in multiple equipment and facilities, including: 

• Water Tanks: To detect the water level and control the water pump.
• Sump Pumps/Pits: Float switches are used in sump pits to detect the water level and turn it on or off.
• Sewage Systems: Float switches are used in sewage systems to control the water level in the sewage tank.
• Industrial Applications: Float switches are used in various industrial applications, including chemicals and food and beverages, to control liquid levels in tanks, washers, containers, and machines.
• Refrigerators and air conditioning units: Controlling and adjusting water levels.
• Coolant and Fuel Tanks: To detect and adjust liquids at optimum levels.