Main Difference – Capacitor vs. Condenser
Capacitors and condensers are components used in electric circuits, which can store charge. Both terms describe the same component and essentially there is no difference. However, the term condenser had been the word used to describe capacitors historically. The word capacitor came into use several decades ago and now it is used more commonly, although the word condenser is still in use as well. So, the main difference between capacitor and condenser is that the term capacitor is a relatively newer term while condenser is an older term.
What is a Capacitor
A capacitor is a device used to store charge in an electric circuit. It consists of two conductors on which charge can be stored, separated by a layer of dielectric. Capacitors have the following circuit symbol:
Symbol for a Capacitor
When a capacitor is connected across the terminals of a cell, the positive side of the cell can draw out negatively-charged electrons from one plate in the capacitor and deposit negative charges on the other side. This causes a potential difference to build up across the capacitor, which opposes the potential difference across the battery. This slows down the current, and eventually brings the flow of electrons in the circuit to a complete halt.
If the battery is removed and the two terminals of the capacitor are connected via a resistor, then the potential difference across the capacitor can now drive a current: the excess electrons from the negative side of the capacitor attempt to flow to the positive side. As this happens, the potential difference across the capacitor drops exponentially, and so does the current. Eventually, charges would be evenly distributed across the capacitor’s plates once again. The potential difference across the plates drops to 0 at this point, and the current stops.
The ability of a capacitor to cause the current in a circuit to drop exponentially is extremely useful. For instance, it is used for smoothing current fluctuations in AC circuits, and for slowly dimming lights once they have been switched off (for example, the roof light inside cars). There are many different types of capacitors, and they come in many shapes and sizes. The image below shows various different types of capacitors:
Various types of Capacitors
What is a Condensor
Condenser is an older word for a capacitor. In fact, the term is a misnomer. The first types of capacitors to be made were Leyden jars (shown below). These were built in the 1700s, and people at the time thought that electric current was like a fluid and that Leyden jars stored charges by condensing the fluid.
A Leyden Jar
The use of the term condenser has largely been replaced by the term capacitor in many fields of science and engineering, although “condenser” is still occasionally used. For instance, in automobile engineering, the word “condenser” is still frequently used to refer to capacitors.
The term condenser is also used to refer to devices that can cause a gas to change its phase into a liquid. However, this is an entirely different usage of the term.
Difference Between Capacitor and Condenser
Usage of the Term
Capacitor is a more modern term.
Condenser is an older term of the capacitor.
References
Farber, J. W. (2006). Essential Electronics for PC Technicians. New Delhi: Firewall Media.
Image Courtesy
“Types of Capacitor.” by Uploader is Jwratner1 at English Wikipedia. (Vectorized from raster image at English Wikipedia) [Public Domain], via Wikimedia Commons (Modified)
“Capacitors” by Windell Oskay (Own work) [CC BY 2.0], via flickr
“Drawing of a Leyden jar, a piece of antique scientific apparatus used to store electric charge, from a 1919 physics text…” by Chetvorno (Downloaded August 13, 2013 from Robert Alexander Houstoun 1919 Elements of Physics, Longmans, Green and Co., New York, p. 176, fig. 170 on Google Books) [Public Domain], via Wikipedia
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