wire

Painting is the process of coating the enameled wire paint on the metal conductor to form a uniform paint layer with a certain thickness. The number of painting passes is affected by the solid content, viscosity, surface tension, contact angle, drying speed, painting method, and thickness of the paint layer. The general enameled wire paint needs to be coated and baked many times to make the solvent evaporate fully, the lacquer resin reacts completely, and a good paint film is formed.

Telephone cable is usually thought of only as a communication medium operating at a normal 48 Vdc level. But telephone cable is regularly used by telephone operating companies to supply power to remote telephony equipment such as: PCM (Pulse Code Modulation) repeaters, FDM (Frequency Division Modulation) repeaters, telegraph and various types of control circuits. The normal talk battery voltage is regularly exceeded in the case of long subscriber loops utilizing loop extenders and on dial long line circuits which operate in the 70 to 100 Vdc range. For these applications, the referenced devices are generally current limited to approximately 150 milliamps. In all such cases, normal telephone industry practice usually limits pair-toground applied voltage to 150 Vdc, and pair-to-pair voltage is usually limited to 300 Vdc.