A stud diode, often referred to as a stud mounted diode, is an electrical component with two terminals that allows the flow of electricity in a single direction. The construction of stud diodes greatly varies based on user preference and needs, but the general layout consists of a stud mount and a diode circuit. Many types of diodes can be referred to as a stud diode since the stud diode refers only to the construction and not the type of diode. There are two classes of diodes that can be stud mounted: signal diodes and rectifier diodes. Signal diodes allow the flow of small electrical currents up to 100 milliamps (mA) while rectifier diodes convert an alternating current into a direct current, having a drop of forward voltage of 0.7 Volts (V).
The stud diode construction consists of a housing component that includes an enclosed electronic element in a jacket from which a stud extends. In the stud, a fastener head is integrally attached and disposed in relation to the jacket by coaxial space. The stud also has a portion of spacing shank that is between the fastener head and jacket, and includes a surface that is heat radiating. A stud diode like this would be used for an application requiring high electrical currents.
Parts of a stud diode are made of semiconductor material. A single face of this material can be soldered or welded to the mounting stud’s head, which will constitute one of the device’s electrical terminals. One metal pin, or one terminal wire, is soldered or welded to the face opposite the element that is active, which constitutes a second electrical terminal in the diode device. A metal sleeve that is cylindrical in shape attaches to a stud’s head and along a flange portion, while the metal pin or terminal wire extends through a sleeve containing insulating material. This is a beneficial diode construction because one active element’s face is in direct contact with the mounting stud’s head.
A stud diode has aspects that differentiate it from normally constructed diodes. These aspects include having a current capable of a high surge, a current range that is wide, and versions of a stud cathode and a stud anode. These are especially useful if the diode is a rectifier diode. The stud diode is designed to be mounted into a fixed location, usually for applications like battery chargers, power supplies, converters, traction applications, controls for machine tools, and power drives.