Individual letters and other designs are then attached to each other and ultimately to a power source. Many neon signs require 10,000 to 15,000 volts of electricity to cause trapped gases to glow, but the amperage is still relatively low and safe for humans. Because neon tubes are easily damaged, however, many sign owners still place their signs out of reach of children.
Led signs can be designed to be static displays, such as the ubiquitous Open/Closed signs in restaurants, or they can be animated. A series of different neon lights can be switched on and off to give the illusion of motion. Back in the Golden Era of neon signs, from the 1940s through the 1960s, advertisers and promoters used animation techniques to draw customers into casinos and theaters.
Advances in electronics have almost eliminated the need for true neon signs, but a number of business owners still prefer the glowing effect and nostalgic value of neon. The craft of glass bending is still practiced by a few specialists and repairs to broken neon signs can still be made, but the expense for elaborate designs can be prohibitive. It is not unusual to find electronic signs which use the same intense pastel colors as the neon signs of old, but their illumination sources may be incandescent bulbs or fluorescent lights surrounded by color filters.