A DC solenoid is an electromagnetic actuation device designed to operate specifically with a direct current (DC) electrical power source. These devices are similar in most respects to an alternating current, or AC solenoid, and consist of a static wire coil and a spring-loaded moving plunger. When the solenoid coil is energized by a suitable DC supply, a strong magnetic field is induced around it that attracts the ferrous metal plunger. The movement of the plunger then produces the solenoid actuation or switching motion. The DC solenoid is found in many industries and is particularly prevalent in automobile, aviation, and marine applications.
Mains grip power supplies produce what is known as alternating current, or AC power. This power "alternates" polarity, or the relationship between the negative and positive position, approximately 50 to 60 times per second. The output produced by a battery, mobile phone charger, or rectified power supply is direct current, or DC power, and features a constant negative/positive relationship with none of the sinusoidal wave form of an AC supply. Typically, appliances and equipment rated for a DC supply cannot be used with AC power and vice versa. The DC solenoid, for example, is specifically designed to operate on a direct current power supply.
In fairly simplistic terms, the DC solenoid is a remote electrical switching device. It may be installed on any secondary mechanism that requires some sort of motion to activate, such as a valve, switch, or a machine component. When energized, it will provide the necessary motion courtesy of electromagnetic attraction. The motion-providing process in question is fairly simple and revolves around a strong magnetic field generated around the solenoid coil when it is energized. This field attracts a ferrous metal plunger placed in close proximity to the coil, which moves rapidly towards it, supplying the actuation for the secondary mechanism in the process.
The DC solenoid may be found in a wide range of applications in the industrial, domestic, and manufacturing industries. The automotive, aviation, and marine industries are amongst the more prolific users of these devices, with most remote systems switching functions, such as fuel and air conditioning valves being facilitated by DC solenoids. Most generic DC solenoid coils are rated for voltages ranging from 12 to 48 volts, although specially-rated coils are common in parts made for specific system applications. Coil voltages should thus be carefully checked before installing replacement parts to avoid solenoid damage.