Capacitors Blog

When sinusiodal or ripple voltage applied to DC Ceramic Disc Capacitors, be sure to maintain the peak-to-peak value or the Peak value of the sum of both AC + DC within the rated voltage.

When start or stop applying the voltage, resonance may generate irregular voltage.

When rectangular or Pulse Wave Voltage is applied to DC Ceramic Disc Capacitors, the self-heating generated by the capacitor is higher than the sinusoidal application with the same frequency. The allowable voltage rating for the rectangular or pulse wave corresponds approximately with the allowable voltage of a sinusoidal wave with the double fundamental frequency.

The allowable voltage varies, depending on the voltage and the waveform.

Silver mica capacitors, also known as silvered mica capacitors, rendered traditional mica capacitors obsolete. Instead of being clamped with foils these use sheets of mica coated on both sides with deposited metal. The assembly is dipped in epoxy. The advantages are:

1.greater stability, since there are no capacitive airgaps that can change dimension

2.airtight enclosure removes the risk of oxidation or corrosion of plates or connections.

3.greater capacitance per volume, since

• there are no airgaps between plates and mica,
• the conducting surfaces can be thinner.
• no clamping mechanism is needed

In analog computers, high precision potentiometers are used to scale intermediate results by desired constant factors, or to set initial conditions for a calculation. A motor-driven potentiometer may be used as a function generator, using a non-linear resistance card to supply approximations to trigonometric functions. For example, the shaft rotation might represent an angle, and the voltage division ratio can be made proportional to the cosine of the angle.