Why do police car lights alternate between blue and red?
Because red is the true color of warm colors and has a warning function, while blue is the true color of cool colors, which forms a sharp contrast with red and can attract people’s attention. The lights and sirens are there to warn passersby to give way so the police can take action. At the same time, it can also deter criminals.
Warning lights are usually used to maintain road safety, usually used in police cars, engineering vehicles, fire trucks, emergency vehicles, preventive management vehicles, road maintenance vehicles, tractors, emergency A/S machinery, electricity, machine tools, chemicals, telecommunications, ships, Functions such as control signal interlocking in electrical control circuits such as metallurgy.
Generally speaking, warning lights can be provided in various lengths according to the vehicle type and application, and have the structure of lamp cover combination. When necessary, composite colors can be combined on one side of the lamp cover.
The shape characteristics of the installed warning lights can be divided into: combined long row warning lights, combined tower warning lights, various small warning lights, etc.
Warning lights can be used in various situations. They are illuminated warning lights in one or more colors. Some warning lights can also be equipped with audible components, which can transmit a loud alarm sound and flash light at the same time. We also call this kind of warning light an audible and visual alarm or a warning light alarm.
Classification and introduction of warning lights:
1. Bulb type
Bulb-type warning lights are actually similar to the light bulbs we used to use. Light is emitted by passing an electric current through a heating wire, usually using a spiral black wire, and injecting a rare gas into the light.
Features: The voltage used is much lower than the rated voltage of the bulb, and AC is generally used, the service life is also increased by nearly 40%, and the power consumption is as low as about 80%.
2. LED type warning light
LED is a warning light made of light-emitting diodes, so the photoelectric conversion efficiency is very high, and it is an energy-saving and long-lived lamp, which is widely used in the market. The life of the LED is affected by factors such as excessive pressure and nearby temperature, but due to the volatilization of the filament, it will not gradually become thinner like a light bulb, and there will be no mechanical wear. Therefore, the featureless seismic structure can also resist shock, vibration and has a long service life.
Post time: Aug-05-2022