IN PRACTICE

摘要

I bought a box of surplus 470μF 450V electrolytic capacitors recently, andamamazed at their small size (only 35mm diameter and 50mm long). Is this a typical package size for such components nowadays? Also I don't see a vent hole or plug - do they 'blow their top' upwards or downwards? The size of electrolytic capacitors has decreased dramatically in recent years. Size is related to two properties: capacitance and heat dissipation. Most electrolytic capacitors are based on aluminium, and use a very thin layer of aluminium oxide as the dielectric insulator between sheets of aluminium foil (Fig 1).