How Vacuum Switches Work?
Switches are mechanical or electronic components that are commonplace in countless circuits, capable of interrupting or diverting current for the means of managing electricity. As binary components, switches can either be in an on or off state. There are also many types of switches that one may use, each differing in its capabilities, operations, and advantages. In this blog, we will discuss the vacuum switch in particular, those of which are commonly found in electric heaters, waste oil heating systems, residential boilers, and more.
As a type of pressure switch that is either mechanical or electrical in nature, vacuum switches rely on vacuum level changes in liquids or gases to switch between on and off positions. Once a specific vacuum level has been reached, the switch will produce a signal for pneumatic, solid-state, or electro-mehcanical switches to make a change. When searching for the right vacuum switch for a particular application, it is important to consider the vacuum range that the switch will be operating over, or the range over which linear output is required.
As previously mentioned, vacuum switches are either constructed with an electro-mechanical or solid-state switch construction. Based on the functionality of a system, a vacuum switch can either be normally open (NO) or normally closed (NC) in its resting state, and single pole (SP), double pole (DP), and other configurations are all common. Additionally, the throw type of a vacuum switch will vary, the two most common designs being single throw (ST) and double throw (DT) variations. When considering the electrical characteristics of a potential vacuum switch, important factors to be aware of are switched currents, AC volts, and DC volts.
In order for vacuum switches to optimally switch between positions for managing liquids and gases, they rely on their sensor element. Generally, such technologies come in the form of pistons, diaphragms, strain gages, semiconductor piezoresistive elements, piezoelectric elements, MEMS, variable capacitance parts, or vibrating elements. All of these perform to achieve the same end result, typically differing in how vacuum states are measured. Alongside such features, it is also crucial that one considers switch accuracy, the materials that are to be measured, and temperature qualities before making a purchase. If vibration or heat is an environmental stressor that such switches will face, they need to have ample resistances.
As some applications will cause measurement noise or pressure pulsing, vacuum switches require two different switch points so that they can remain stable and avoid irregular oscillation. These switch points are known as the setpoint value and hysteresis value. As an example of these switch points in action, when the setpoint value of vacuum pressure is passed for a normally open contact, the relay will be energized so that the contact closes. Once the hysteresis value is exceeded, the switch will then open back up. This ensures more smooth operations as pressures fluctuate, ensuring optimal functionality.
If you find yourself in need of various vacuum switches for your operations or systems, look no further than NSN Axis. NSN Axis is a trusted distributor of countless aircraft parts and other component types, presenting an inventory of over 2 billion items for our customers to explore. All listed items on our database are ready for purchase at any time, and customers may take advantage of our RFQ service to easily request personalized quotes for their comparisons. Additionally, we can meet the time constraints of our customers, utilizing our expansive supply chain network stretching across the United States, Canada, and the United Kingdom to expedite shipping for both domestic and international customers alike. Get in touch with a representative at your earliest convenience, and see how we can serve as your strategic sourcing partner on NSN Axis.
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