Applications of capacitors
Capacitors are used in various electronics circuits. A few of the applications.
(a) Most people are now familiar with the digital camera. The flash which comes from the camera when we take photographs is due to the energy released from the capacitor, called a flash capacitor (Figure 1.57 (a))
(b) During cardiac arrest, a device called heart defibrillator is used to give a sudden surge of a large amount of electrical energy to the patient’s chest to retrieve the normal heart function. This defibrillator uses a capacitor of 175 μF charged to a high voltage of around 2000 V. This is shown in Figure 1.57(b).
(c) Capacitors are used in the ignition system of automobile engines to eliminate sparking
(d) Capacitors are used to reduce power fluctuations in power supplies and to increase the efficiency of power transmission.
However, capacitors have disadvantage as well. Even after the battery or power supply is removed, the capacitor stores charges and energy for some time. For example if the TV is switched off, it is always advisable to not touch the back side of the TV panel.