ENERGY BUTTONS that fit into your light socket will make your light bulbs last longer, but they can be dangerous if improperly used and will lessen your bulb's light output, according to an April 1980 Department of Energy report. b

The buttons lessen your light from 10 to 74 percent depending on the device. The hazards occur primarily in the installation.

Dr. Rudy Verderber, who along with Oliver Morse of DOE's Lawrence-Berkeley Laboratory examined the cost effectiveness of these buttons as well as long-life light bulbs, said in a recent telephone interview that the laboratory tests also studied the difference between the two types of energy buttons the thermistor and the diode. "Both are similar in appearance and the consumer could easily select one when the other was the one they really wanted," explained Verderber.

The thermistor button, produced by American-Electro Dynamics, is called the Bulb-Miser. It is a silicone rubber disc -- about one inch in diameter -- that fits into the light bulb socket. In the center of the disc is a smaller disc, called a thermistor. The thermitor is a thermally sensitive resistor that is insulated by the rubber around it.

The Bulb-Miser snaps into any medium-base incandescent light socket and works with bulbs from 3 to 300 watts, AC or DC, 6 to 300 volts. It cannot be used with fluorescent lighting or three-way bulbs. (Three-way sockets are fine.)

The light bulb screws in on top of this disc. When the light bulbs is turned on, the Bulb-Miser's thermistor prevents the initial high surge of power in the filament of a light bulb. Instead of the starting jolt -- up to 15 amperes -- the Bulb-Miser allows the power to come on gently -- only to one ampere, the level where the current remains while the light is on.

When installing the Bulb-Miser, the center contact of the socket must be raised enough to touch the metal part of the Bulb-Miser. The rubber rim of the Bulb-Miser keeps it from falling -- regardless of the socket's position, according to the manufacturers.

The diode button is also a small disc that pops into the light socket. Some diode brand names currently on the market include: the OPEC button, the SAK button, Light-Saver, the Miracle Energy button and U.S. Energy Systems. There are others, according to Verdeber, some come and some go.

Engineer Nick Piccini of Eagle Electric Manufacturing Co., which makes the Eagle Energy (diode) Button, says the center of this disc contains a thin strip called a diode. "The diode behaves like a rectifier, cutting the alternating current in half. This cuts the bulb voltage in half as well as reduces the light output by half." The diode button cannot be used with a bulb over 100 watts.

One problem the consumer faces when using these devices, according to the DOE report, is that the buttons do present " a potential safety hazard in the installation and during operation. . . . In the use of the energy button these safety hazards must be recognized and avoided by the personnel that install or handle this equipment."

The consumer should be very careful when inserting the buttons. According to the DOE report, they pose a potential shock hazard if the current is not turned off during installation.

In some sockets, the energy buttons -- both the diode and thermistor -- would shorten the depth at which the lamp can be inserted. As a result the electrically charged portion of the bulb might stick up above the socket. "Accidental contact with this portion and with an electrical ground can result in a serious shock," says the report.

Because the socket temperature of a 100-watt bulb rises with a thermistor energy button -- to about 105 degrees -- the socket's high temperature "presents a potential fire hazard," states the report. "While the 105-degree temperature does not exceed the fire code, some lamps may be used in enclosed fixtures that have no ventilation. In these applications, safe socket temperatures could be exceeded, resulting in fire."

Dr. Ira Wolff, president of American Electro-Dynamics Corp., says that "yes, the thermistor does raise the heat of the socket -- sometimes as high as 125 degrees, but this is way below UL [Underwriters Laboratories] and ANSI [American National Standards Institute] standards."

UL and ANSI say the maximum temperature allowed on the screw shell and the center contact of the socket is 200 degrees. Engineering group leader Tony Castellone of UL's Melville, N.Y., office cautioned that "the 200-degree limit applies specifically to those parts of the socket mentioned. The maximum safe temperature on other parts of the socket varies with the material. Everything that gets put into a socket isn't safe at 200 degrees."

"A fire is just not possible," contends Wolf. "We have product liability insurance and we have never had a claim yet."

The Consumer Product Safety Commission issued a preliminary report on Bulb-Miser stating that they'd found nothing wrong with it yet, but were continuing to study it.

"We have done some tests," says Bert Simson, director of the Office of Program Management at CPSC, "and we're continuing to look at it. We've never endorsed it. Our silence may mean we haven't found anything wrong, but that doesn't mean it's okay."

Simson added, "The CPSC never endorses something. We only investigate a product if questions have been raised about its safety."

In addition to CPSC, according to Wolf's partner, Donald Ornstein, Bulb-Miser was found to be okay when American-Electro Dynamics had it tested by Sargent Engineering (Houston), ETL Testing (New York City) and Applied Research Laboratories (Miami).

The reduction in light is another factor to consider with these devices. The consumer might not realize the difference in light with and without the energy button, since, as Verderber points out, the eye is not a good gauge of light change -- "the iris adjusts to a dimmer/brighter environment within seconds."

Robert Boettner, DOE program manager in charge of the lighting program in the Technology and Consumer Products branch, said: "We discovered that the diode-type buttons drastically diminish the light output. A 100-watt bulb used with a diode button will only give as much light as a 40-watt bulb. The thermistor buttons also reduce the amount of light received, but only by 10 percent. A 100-watt bulb [used with a thermistor disc] provides the same amount of light as a 90-watt -- if they made a 90 watt."

A simple alternative to the diode would be to install a lower watt bulb; ie. replace a 100 watt bulb and diode with a 40 watt bulb.

Manufacturers of the buttons readily admit to the loss in light, yet defend the gadget since it does, as the DOE report indicated, make the light bulb last longer (the thermistor-type button caused the bulb to last three times longer, while the diode button was shown to make the bulb last 50 times longer). The manufacturers' responses:

Bulb-Miser's Wolf says that "although light meters do reveal a small decrease in lumen output when the Bulb-Miser is used [.02 amperes with a 100 watt bulb], there is no lighting difference visible to the naked eye, once the filament is completely heated."

Piccini says consumers should not use the diode button where they need bright light. "It's great for exit signs, outside lights, apartment stairwells -- any place that's difficult to reach." His point is well taken since the DOE reports shows that "diode-type button reduce the input power to the 100-watt incandescent lamp [light bulb] by 42 percent, while the light output of the lamp [bulb] decreases by 74 percent."

DOE's Bob Boetner said that the study of the buttons was undertaken after several of the manufacturers came to DOE and asked the agency to promote their products. DOE studies products but does not promote them, according to Boetner. "There are a lot of conservation items on the market today. Our concern is to tell the consumer if they work."

While the various types of diode energy buttons have been on the market for more than a decade, the thermistor energy button, the Bulb-Miser, is a relative newcomer to the field.

Ira Wolf and Donald Ornstein first became interested in the Bulb-Miser when they saw an article in the Midnight Globe. "It was the only paper you could find during the newspaper strike in October '78," recalls Wolf.

The article began: "Thanks to modern technology we, at NASA, have developed a device that will increase the life of your light bulb. The Bule-Miser, used in Apollo flights to the moon, can now be used at home. . . ."

"Just think," thought Wolf, who was then mathematics professor at Brooklyn College, "if that thing really works, you could made a fortune -- everyone uses light bulbs."

Ornstein, then a businessman in real estate, agreed with him and together the two set about investigating the Bulb-Miser. They tested it for about a year and convinced themselves that it was a device the average consumer could use. "We felt good about the product. Coming from the world of academia this was especially important to me," said Wolf. They bought the patent rights in 1979 and formed the American Electro-Dynamics Corp.

The gadgets, according to Wolf, were first marketed in 1979 for commercial building managers who wanted to save money, not only on bulbs, but on labor to change bulbs.

According to Wolf, the Bulb-Miser never needs to be replaced. When the light-bulb burns out, another bulb can be put in on top of the same Bulb-Miser.

"The reason light bulbs burn out when you turn the current on," observes Wolf, "is that the initial surge of electricity heats up the cold filament to over 4,000 degrees within 1/10 of a second.The filament gets weaker each time the light is turned on and has to sustain this thermal shock. Finally the filament fails.

"Bulb-Miser will not prevent your light bulb from burning out -- but instead of changing it 3-4 times in the course of a year, you only need to change it once." It also prolongs the life of a bulb that stays on constantly, he added.

Bulb-Misers are being sold at some area hardware stores for $2.99.