Capacitive Technology and its Uses
A capacitor is a device which stores electric charge. Capacitors vary in shape and size, but the basic configuration is two conductors separated by a dielectric.
The two conductors have the ability to store energy in an electric field between the electrodes when a voltage is applied to the circuit. The property of capacitance relates to the amount of energy stored in this field relative to the applied voltage.
The dielectric is an insulating material, such as ceramic or plastic, between the conductors. This material can be used to maintain a physical separation between the plates forming the electrodes.
The dielectric dictates what kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some capacitors are better for high frequency uses, while some are better for high voltage applications, as outlined below;
- Air - Often used in radio tuning circuits
- Mylar - Most commonly used for timer circuits like clocks, alarms and counters
- Glass - Good for high voltage applications
- Ceramic - Used for high frequency purposes like antennas, X-ray and MRI machines
- Super capacitor - Powers electric and hybrid cars
Since dielectrics break down less easily than air, charge leakage can be minimised, especially when high voltage is applied. Capacitance increases when the space between the electrodes is completely filled.
Capacitors have many important applications in electronics, such as storing electrical potential energy, delaying voltage changes, filtering out unwanted frequency signals when coupled with resistors , forming resonant circuits and making frequency-dependant and independent voltage dividers when combined with resistors.
Gill R&D utilises the principles of capacitive technology in the design and manufacture of liquid level sensors. By constructing the sensor probe from an outer tube and concentric inner rod – forming the two conductors – the measured liquid forms the dielectric and flows into the space between the two conductors. As the liquid level changes so does the capacitance, and it is this change that the integrated sensor electronics convert into an accurate level output signal.
This practical application of the technology provides us with an in-depth knowledge and expertise, enabling us to exploit the technology in an informed and innovative way to the advantage of our customers.
Gill Research & Development Limited is an innovative hardware, software and product design consultancy, offering services to external clients and sister Gill companies.
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