I want to know if I can "split" a headlamp wire on a car's 12-volt system into 2-6 volt headlamps by going in series. Also, can I wire a 240v leg (AC) into series with 2 porcelain 120v fixtures and get away with it?
2006-12-19 03:34:02 · 5 answers · asked by Nathan L 2 in Science & Mathematics ➔ Engineering
Yes will work. The main problems are that the current will be doubled so your wiring may not be strong enough. 6 Volt wiring is much thicker than 12. If one lamp fails the other will go out too. If one lamp shorts it will take out the other lamp with it. The cold resistance will be very low so it might have an excessive load when you switch on.
2006-12-19 03:42:48 · answer #1 · answered by Anonymous · 0⤊ 0⤋
You would not be doing anything too dangerous, except that mentioned about having a 120 volts from either conductor to the wire that connects the lamps on the 240 volt circuit.
In either case you might find that one lamp burns brighter than the other. This would be because of resistance differences in the two lamps.
2006-12-19 17:57:47 · answer #2 · answered by Ed 6 · 0⤊ 0⤋
In both situations you describe, the total voltage drop will be in proportion to the resistance of each device you put in series.
If both devices have equal resistance, each one will see 1/2 the total voltage.
If one device has 2x the resistance of the other, it will see 2/3 of the voltage and the other device will see 1/3.
So in your light bulb example, you can put two 120V light bulbs in series on a 240V circuit. However, if they are not evenly matched, one of them will burn out quickly.
If you try to put two appliances in series, unless they have identical load characteristics, one of them will see much higher voltage than it was designed for.
Basically, while this is something that looks like it should work in theory, in practice you will find it difficult to get the results you expect.
The headlamps you mention in the first part of the question likely will work OK, as long as they are identical headlamps. (not one low-beam, one high-beam, for example.)
2006-12-19 19:43:44 · answer #3 · answered by AnswerMan 4 · 0⤊ 0⤋
Why not splice into both wires so they can be wired in parallel, then ther will be no votage drop. Otherwise, voltage will be cut in half. For your 240V question, you can run either of the hot wires to the lamps and the other to your white neutral and you will have 120 V. You will only have 240 V if you use BOTH hot wires instead of one and the neutral.
2006-12-19 12:15:15 · answer #4 · answered by captainskully2000 1 · 0⤊ 0⤋
I presume you have only one live of 240V. So the only way you can do it is by having the two bulbs in series. Be careful though one of your bulbs will be live on both sides - not advisable if they are screw bulbs - you may get away with it if they are bayonet.
2006-12-19 12:43:32 · answer #5 · answered by deflagrated 4 · 0⤊ 0⤋