Pull-down resistors are used in electronic input circuits in order to ensure that safe switching is possible even for minimal signal strengths. Signal pathways must not cause interference that can negatively affect safety. It is important to make sure that control currents are only allowed to flow in the proper direction. These challenges are met by the use of diode modules.
Weidmüller has developed a compact, rail-mount solution that brings together the required functions into the smallest possible form factor. The compact assembly allows 8 resistors with 3 watts or 8 power diodes with 3 amps to all be put into a single housing. Compared to conventional modular solutions, this compact solution uses more than 50 percent less space on the mounting rail.
The modules make use of a special circuit board to divert the heat generated from the components to the housing. The housing then functions as a heat sink by dispersing the heat to the surrounding air. Because of this efficient heat transfer system, these modules can be used reliably with surrounding temperatures of up to 70°C.
The housing also ensures that the module is resistant to vibration so that it can function smoothly when installed in train electrical cabinets.