Abstract: A display circuit board is provided for a heat dissipation system. The heat dissipation system includes a fan tray, a control circuit board, a plurality of fans, and a display circuit board. The display circuit board includes a plurality of light emitting diodes (LEDs), a thermal sensor, and a connector. After the thermal sensor detects the temperature around the heat dissipation system and transmits a temperature signal to the control circuit board through a signal transmitting cable, the control circuit board adjusts the rotation speeds of the plurality of fans according to the temperature signal, and further transmits a plurality of display signals, which indicate the operation situation of the plurality of fans to the corresponding LEDs through the signal transmitting cable.

Abstract: A relay terminal includes a plurality of relays, a connector for entering control signals to control the relays and outputting contact inputs from their relay contacts, and a terminal block corresponding to the input and output signals of the relays, which are held as a single unit. The holding construction of the plurality of relays and the terminal block employs a two step overlapping holding construction in which the relays are held in an upper step and the terminal block is held in a lower step, resulting in a reduction in the width of the relay terminal and an increase in a package density when the relay terminal is mounted on a vertical installation wall within a control panel.

Abstract: A high density packaging arrangement for electronics systems wherein a plurality of circuit board assemblies are provided with electronic components on one side and cooling tubes on the other side. The assemblies are arranged such that the cooling tubes mounted on one board cool the electronic components mounted on an adjacent board. Electronic contact elements are provided on the circuit board surfaces, to allow electrical interconnection of the electronic components mounted on adjacent boards.