Note on the selection of film capacitors (2)

3. Capacitor capacity and lead span selection:

1) Capacity selection must be within the E24 series of values:

1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1 total 24 , where the horizontal line below is the E12 series value, which is the preferred series value.

2) The range of capacity values shall be in accordance with the capacity range given in the general specifications of various types of capacitors:

The specifications of the specifications provided by different manufacturers may have slightly different upper and lower limits. However, if the capacity selection value is significantly lower than the lower limit of the category, it should be selected in the ceramic capacitor. Otherwise, if the capacity value is high. The upper limit of this category should be selected in the electrolytic capacitor.

3) Selection of lead forming pitch:

For different types of film capacitors with different specifications, the lead pitch P has a certain value in the manufacturer's specification. However, in actual use, according to the PCB assembly requirements, the manufacturer can be required to form the supply, and the pitch of the formed foot is given. Size requirements. However, since the user does not consider the actual value of the natural pitch P of the capacitor, the F-value of the forming pitch is randomly determined, resulting in many unreasonable molding sizes, that is, affecting the process assembly effect, and causing great difficulty for the supplier to supply. It must be highly valued by the user, and the forming pitch F should be as close as possible to the normal pitch P of the capacitor, and the following molding standards must be observed:

When P≥F, P-F≤8mm (F value is an integral multiple of 2.5);

When P < F, F-P ≤ 5 mm (F value is an integral multiple of 2.5).