Pulse Counting Type
When an application requires the volume of a fluid, or a distance, or the RPM of a machine tool measured, such an application can be classified as a pulse counting application.
The basic principle of pulse counting is to use a reed switch or a reed sensor on a fixed surface, with a multi-pole ring magnet attached or embedded to the center of the wheel or counter. The best practice is to use ring magnets with two poles for high speed applications and to use ring magnets with 4 or more poles for low speed applications, for better accuracy. When the sensing circuit is low in the range of milli-amperes, the basic reed switch does the job for up to a billion operations.
Reed Switches works so well in pulse counting type applications as they have a very high operating frequency. The Reed Switches used generate a square wave that can then be translated to the actual consumption of fluid, or energy, or the measurement of wheel speeds. As the wheel rotates, the multi-pole magnet’s alternating North and South poles turn the reed switch on and off continuously and this generates the square wave pulse. This pulse output is used by control circuits to display the actual measurement. The translation of number of pulses to the actual unit of measurement is achieved initially, by conducting various trials. More information regarding magnet actuation of reed switches is available here.
For pulse counting applications using larger wheels, where the diameter of the magnet is more and the pole moves away far enough to open the reed switch, any standard reed switch with a differential of 40-50% can be used. But for very tiny wheels in water and gas meters, it is important the reed switches with a close differential or 70% minimum differential are used. This is to ensure that the reed switch opens immediately as the magnetic pole moves away, so that the reed switch does not remain closed at any point.
Reed Switches are hermetically sealed, they are immune to dust and moisture, and can safely be used in environments with extreme dirt and moisture. Pulse counting for applications can also be achieved by using active devices like Hall effect sensors, but Reed Switches and Reed Sensors, are passive, have more advantage as no power is consumed for operation, and have no leakage current across the contacts, that need to be compensated for. Some of the pulse counting applications are listed below.
Example Applications
Dialysis Machine Flow Rate Sensing Using Reed Sensors
Dialysis machines are life-saving devices used to filter waste and excess fluids from the blood when the kidneys are unable to function
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Oct 26, 2024 |
Automatic Gates Use Magnet Sensors for Motor Control
Automatic gates are a common feature in gated compounds, providing security and convenience. Traditionally, these gates are operated by
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Sep 11, 2024 |
Valve Position Sensing Using Reed Sensors
In industries such as water purification, gas, and chemicals, precise control over the cleaning and filtering processes is critical.
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Sep 3, 2024 |
Layering during Coil Winding Using Reed Sensors
A coil winder is an essential machine in the manufacturing of bobbins, inductors, transformers, motors, and other electromagnetic
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Sep 3, 2024 |
Surveyor’s Wheel Uses Reed Switches for Distance Measurement
A Surveyor's Wheel, also known as a Trundle Wheel, serves as a fundamental tool for measuring distances efficiently. Designed with
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Sep 3, 2024 |
Sun-shade Shutter Control Applications Using Reed Sensors
Sun-shade shutter control systems in Smart Homes are revolutionizing the way we manage light and privacy within living spaces. These
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Sep 3, 2024 |
Reed Sensors in Automobile Power windows
In modern automobiles, the convenience of raising or lowering power windows is facilitated by buttons located near the seats or on the
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Sep 3, 2024 |
Control of Automobile Sunroofs Using Reed Switches
An automotive sunroofs, typically constructed from tinted glass, serve as a movable panel that offers the flexibility to be fully or
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Sep 3, 2024 |
Fuel Pumps Use Reed Switches to measure Volume of fuel
Fuel pumps represent inherently hazardous environments where even the slightest error can precipitate a catastrophic fire. Given this
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Sep 3, 2024 |
Bicycle and E-bike Speedometers Use Magnet Sensors
Fitness enthusiasts rely on accurate feedback to track their progress and performance metrics, whether it's calorie burn, distance
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Sep 3, 2024 |
Treadmills Use Magnet Sensors for Belt Speed Sensing
Magnet Sensors find a few applications in treadmills for speed and gradient sensing. The speed of the belt is determined by positioning a
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Sep 3, 2024 |
Fishing Reels Sense “Bites” Using Reed Sensors
Electric Fishing reels represent a technological leap forward from traditional fishing gear, offering enhanced functionality and
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Sep 3, 2024 |
Reed sensors for Tamper-proofing Electricity Meters
Electric companies rely on electricity meters calibrated to measure one kilowatt-hour and determine maximum demand, representing the peak
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Sep 3, 2024 |
Anemometers Use Magnet Sensors record Data
Anemometers serve as indispensable tools for measuring wind speed, pivotal in a wide array of applications including weather forecasting
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Sep 3, 2024 |
Underwater currents in Lakes measured using Flow Meters
The dynamics of underwater currents in lakes and other aquatic ecosystems are influenced by a multitude of factors, ranging from
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Sep 3, 2024 |
Anti-lock braking system (ABS) Use Reed Sensors
The Anti-lock Braking System (ABS) represents a pivotal safety feature utilized not only in vehicles but also in aircraft. In the realm
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Sep 3, 2024 |
Cruise Control Systems use Reed Switches
Cruise Control is an automated feature designed to regulate the speed of a motor vehicle, alleviating the need for the driver to maintain
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Sep 3, 2024 |
Magnet sensors in Satellite dish position sensing in the DTH industry
A satellite dish is a concave device used to transmit and receive information and is used primarily in the direct-to-home (DTH) TV
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Sep 3, 2024 |
A Spirometer Use Reed Sensors to Assess Lung Function
A Lung function test or Pulmonary Function test, PFT for short, is a system to evaluate the respiration system of a patient. It uses a
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Sep 3, 2024 |
Fluid Metering Using Reed Sensors
In many major cities, utility companies or gated communities manage the distribution of piped water and Liquefied Petroleum Gas (LPG) to
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Sep 3, 2024 |