My 4th grader is making a lighthouse with a simple circuit and a 9 volt battery. We are using a flashlight bulb as the light. When we turn it on it lights then the light steadily fades and the battery gets hot. If we take out the battery and let it cool it will turn on again, but the same will happen. We have tried changing to a smaller gauge of wire, putting a new switch on and even replaced the battery but it still happens. Any ideas would be greatly appreacated.
2007-01-21 08:20:26 · 4 answers · asked by shellbell 2 in Education & Reference ➔ Homework Help
Reduce the wattage of yr bulb. Yr drawing too much current out of the battery too quickly.
A 10W bulb will draw (10/9)A = 1.1A
A 5W bulb will draw (5/9)A = 0.56A
A battery is rated at the amount of current it can supply over a period of time. If the battery is not hefty enough to supply the amount of current (and therefore power) to the bulb, it will generate internal resistance and get hot. So either reduce the wattage of the bulb or get a bigger battery. You could use a higher voltage battery and drop some of the voltage across a series resistor...
2007-01-21 08:39:19 · answer #1 · answered by sleakitweasel1 5 · 0⤊ 0⤋
Sounds like the voltage of the bulb is too high, If this is a simple light circuit then use a C cell 1.5 volt battery and a 1.3 to 2 volt flashlight bulb.
2007-01-21 16:32:02 · answer #2 · answered by garidor 3 · 0⤊ 0⤋
You have to match the batttery with the bulb. Usually bulbs are marked ( for flashlights) with what the voltage should be. Each battery you put in sequence adds its voltage. A small 1.5 volt will not have much current to push, two small 1.5 volts can be put in parallel and you double the current (at 1.5 volts) or in series (and you double to voltage 3 volts but no more current than one). ("in series" is like a train each one connected to the next (positive to negative while in parallel has all positive ends connected and all negative ends connected )). My guess is that you have too much voltage and not enough current. Try a 1.5 V D cell.
2007-01-21 16:35:24 · answer #3 · answered by Anonymous · 0⤊ 0⤋
I suspect that the battery is not the right size to power the light bulb. Please check the specifications on the light and make sure that the battery is the proper one
2007-01-21 16:26:57 · answer #4 · answered by Glenn T 3 · 0⤊ 0⤋