How to find condenser capacity

How to find condenser capacity

In order that the nobility whether it is possible to use the condenser in any given place of the scheme, it is necessary to determine its capacity. The way of finding of this parameter depends on how it is designated on the condenser and whether it is designated in general.

It is required to you

  • Capacity measuring instrument


1. On large condensers the capacity is usually designated by clear text: 0.25 mkf or 15 uF. In this case, the way of its definition is trivial.

2. On less large condensers (including, SMD) capacity is designated by two or three figures. In the first case, it is designated in picofarads. In the second case, the first two figures mean capacity, and the third - in what units it is expressed: 1 - dozens of picofarads; 2 - hundreds of picofarads; 3 - nanofarade; 4 - dozens of nanofarade; 5 - the tenth shares of a microfarad.

3. There is also a system of designation of capacity using combinations of Latin letters and figures. Letters designate the following figures: A - 10; B - 11; C - 12; D - 13; E - 15; F - 16; G - 18; H - 20; J - 22; K - 24; L - 27; M - 30; N - 33; P - 36; Q - 39; R - 43; S - 47; T - 51; U - 56; V - 62; W - 68; X - 75; Y - 82; Z - 91. The received number it is necessary to increase by number 10 which is previously built in the degree equal to the figure following after a letter. The result will be expressed in picofarads.

4. Condensers on which capacity is not designated in general meet. You for certain met them, in particular, in starters of fluorescent lamps. In this case, it is possible to measure capacity only by the special device. They are digital and bridge. Anyway, if the condenser is sealed in any given device, it it is necessary to cut off power, discharge in it condensers of the filter and the condenser which capacity should be measured, and only after it vypayat it. Then it needs to be connected to the device. On the digital measuring instrument at first choose the most rough limit, then switch it until it does not show an overload. After that the switch is transferred to one limit back and read indications, and determine by position of the switch in what units they are expressed. On the bridge measuring instrument, consistently switching limits, on each of them scroll the regulator from one end of a scale in another until the sound from the loudspeaker disappears. Having achieved disappearance of a sound, on a scale of the regulator read out result, and units in which it is expressed, also determine by position of the switch. Then the condenser is installed back in the device.

Author: «MirrorInfo» Dream Team