Bahamas acdc power module potting requirements(2)
Power Active Filter
When the traditional alternating current-direct current (AC-DC) converter is put into operation, a large amount of harmonic current will be injected into the power grid, which will cause harmonic loss and interference. For example, when uncontrollable rectification is added with capacitor filtering, the third harmonic content on the grid side can reach (70~80)%, and the power factor on the grid side is only 0.5~0.6.
Epoxies cannot be used for stress-sensitive and module sealing due to their hardness and are basically eliminated by module power supplies. However, due to its low cost, this epoxy is still used in cost-sensitive micropower supplies. Some domestic bad 24V input power supply manufacturers also use this epoxy resin acdc 24V input power supply module. However, due to stress problems, the failure rate of this 24V input power supply is very high, and buyers are miserable.
At present, the most commonly used power module is the addition of silicone. This kind of silica gel is generally 1:1, which is easy to operate. When acdc potting power modules, attention should be paid to its thermal conductivity. However, the bonding ability is not very strong, and it can be improved with primer.
Polyurethane has been used in China for a period of time, but due to its high hardness, inconvenient maintenance, and the price reduction of silicone rubber, the cost performance of polyurethane is not high.