Electrical question about wiring and timers :-)

[muddyjames]

I have bought a 16w 12v dc flourecsent light for the disco. It has 2 8w tubes inside it to make the 16w.

I have a 3amp 5mm cable. Will this be ok for it?

Quickly reply thanked for now as I want to wire this into the disco NOW. have new toy will play!!!

[Evilgoat]

That will be ok, no worries. Draw will be about 1.3A or to be precicse :

1.3333333333333333333333... you get the idea

[Horness]

Watts divided by Volts = Amps

16W divided by 12V = 1.3A

[Sharpshooter]

3 amp cable is more likely 0.5 mm cable.

[att]

Watts divided by Volts = Amps

16W divided by 12V = 1.3A

Brilliant information, thanks. 8)

[muddyjames]

Cheers guys.

I have now completed my wiring and installing. The light isnt as bright as I thought it was going to be but with a 8w light that should be coming soon that will go in the centre of the roof in the boot,  which will be instead of the poxy little light that is supposed to come on when you open the door, it should be nice and light in there for if i need to dig around and find something.

I have placed the 16w light on the bit of plastic in between the alpine light and the back window. It fitted perfectly mounted under there.

I have wired it into the constant 12v for the towing electrics. I hope to get a 12s socket and mount it in the back door sometime but not bought the socket yet. I have a spare in my caravan that is 2 hours away from me!

Mental note though. Dont forget to leave it on!!!

[Range Rover Blues]

Mental note though. Dont forget to leave it on!!!

I could be a smart arse and work out how long it will take to flatten your battery, but how about I suggest some sort of foolproof switching system that will prevent such an error from happening?

[BrumLee]

When you want to calculate energy its simple to draw a triangle and then draw a T inside the triangle, giving you one section at the top and two sections below. Then write a W in the top section, then A in the lower left and V in the lower right.

When you need to find out problems like the one in this topic you substitute W for Watts, V for Volts and A for Amps. Then look at the figures you have like a maths question i.e. W/V = A (24w/12v = 2A)

Using this simple tool you can calculate fuse rating, current draw etc.

HTH  

[muddyjames]

Mental note though. Dont forget to leave it on!!!

I could be a smart arse and work out how long it will take to flatten your battery, but how about I suggest some sort of foolproof switching system that will prevent such an error from happening?

I am thinking about trying to buy a timer so it only stays on for 5 minutes for example like the interior lights on the disco already do.

[muddyjames]

When you want to calculate energy its simple to draw a triangle and then draw a T inside the triangle, giving you one section at the top and two sections below. Then write a W in the top section, then A in the lower left and V in the lower right.

When you need to find out problems like the one in this topic you substitute W for Watts, V for Volts and A for Amps. Then look at the figures you have like a maths question i.e. W/V = A (24w/12v = 2A)

Using this simple tool you can calculate fuse rating, current draw etc.

HTH  

this triangle is really useful as I got taught it at school. I can just never remember which letter goes in which part of the triangle  :oops:  :roll:

[BrumLee]

For timer circuits this LM555 site may help.

[muddyjames]

:shock:  :o  :shock:  :o

I am mega baffled with that site Lee.  It goes on about flip flop timers.  :shock:  :o It has multi colour arrow things and all sorts.

Anyone know of any web sites that do a simple timer that once the current flows through it, it sets the timer off and shuts off after about 5 mins. What about the disco interior timer? Would that be up to the job if I could get hold of a second hand one? There are enough guys breaking disco on here these days!

[BrumLee]

The LM555 semiconductor is the timer part of the circuit, you can google LM555 and see if you can find something. The timer for interior lights etc are built into relays. You can find old relays in breakers and a FORD timer relay was yellow (well it was when I did their advanced electrics & electronics course)

[muddyjames]

I like going around breakers yards :D This could be a good esxcuse to leave wallet at home and only take coins that are in pocket and visit them :D :lol:

[Evilgoat]

I like going around breakers yards :D This could be a good esxcuse to leave wallet at home and only take coins that are in pocket and visit them :D :lol:

I have a timed relay I can bash up for you that behaves like a normal courtesy lamp but will stay on for a minute or two/goes out when you turn the igniton comes on. PM me if you want one.

[muddyjames]

Thanks for the offer. I am hoping for about 5 minutes as if I am unloading my disco then I would like it to be on for about 5minutes.

thanks for the offer.

James

[Evilgoat]

Will calculate out all the timing values tonight and knock one up if you like.

[muddyjames]

pm sent.

[clbarclay]

When you want to calculate energy its simple to draw a triangle and then draw a T inside the triangle, giving you one section at the top and two sections below. Then write a W in the top section, then A in the lower left and V in the lower right.

Sorry to be a bore, but....

Energy is the wrong word, watts is a measure of power.

Power = Energy/Time

or to put it another way power is the rate of energy transphere.

[gtomo2]

Or you could just connect the -ve side of the light to the door swicth for the interior lights that way it wil go off when you close the door

[mark.yellow.series.3]

dont forfget guys that an electrical system on a car is 13.8 vdc. you will get 12.5vdc out of a good car battery, and upto 14 vdc when when the engine is running.

and 555 timers are as old as the hills and subsequntly not that good and with standing surges, so i filter circuit is required.