Industrial Technology Research Institute

Eric Han

Tien-Cheng Hu

Jin-Chyuan Hung

Chien-Hsing Hsien

Wen-Hui Cheng

Ling-Hwei Chang

Hwei-Shong Chun

A control apparatus for a network traffic light is provided with a main control device, a lamp control device, and a pair of power transmission lines connected between the main control device and the lamp control device in a ring-shaped fashion to carry the control signals which control each lamp set at an intersection. In this way, the layout engineering is simplified, and thus its cost is reduced. The ring-shaped layout permits the network traffic light to sustain its operation even if some of its lines are broken during road works. Maintenance of the control apparatus is also easy and fast.

Control apparatus for network traffic light

Disclosed is a starting current limiting device for single-phase induction motors, driven by an AC power supply, used in household electrical equipment. The device is adapted to provide, as the power switch of the induction motor is just turned on, a low and gradually increasing starting current flowing into the induction motor. The device is capable of cutting some portions of each cycle in the waveform of the AC power off such that the average voltage input to the single-phase induction motor is reduced, and/or converting some portions of each cycle to oscillate in the reverse directions such that the waveform of the AC power input to the single-phase induction motor appears to have a lower frequency. The device is provided with a switching circuit including a plurality of thyristors, which can be silicon controlled rectifiers or triacs. A means is provided for generating the triggering signals to fire the thyristors, the triggering signals being predetermined and their timing is controlled by a sequence of timing signals. The sequence of timing signals is generated by a timing signal generator capable of generating a single timing signal every time the AC voltage has a zero-crossing. When the current flowing into the induction motor has reached a predetermined percentage of the rating current, the device would switch off the switching circuit and connect the induction motor directly to the AC power supply.

Starting-current limiting device for single-phase induction motors used

Growing community of inventors

Hsinchu, Taiwan

Eric Han