NB. Sortof 12volt question

[jimbouy]

Hi all.

I spent some time on Saturday fitting a 12volt halogen track in the kitchen.... lots of brownie points.

After 2 hours of use the system blew the fuse in its' transformer unit. /forums/images/graemlins/crazy.gif

So today I managed to get a few new 1.6 amp fuses. But they keep blowing. Even if the whole track is disconected.

The transformer unit consisits of a teroidal (spelling) transformer with the fuse in line on its mains supply.

I've checked all my wiring... including the wall switch.

I can only assume a faulty transformer unit.

The fuse holder says 1.6amp.... I got quick blow.... could this be wrong??

Help, my hard earned brownie points are ebbing away.

Jimbouy

 

[VicMallows]

I'd guess your fitting has 4 x 20w Halogen bulbs? ... in which case 1.6a ordinary fuses should be fine. Does sound like you've got a dud 'transformer'. Are you sure it has a torroidal transformer? .... most are 'electronic converters' these days.(which of course for the purists incorporate mini-transformers).

Vic

 

[jimbouy]

hi Vic

Its got 5 x35w bulbs and yes it most definately is a torroidal transformer, nore's the pity. (SWMBO only goes for looks not practicality)

I think a replacement tranny is the answer.


Jimbouy

 

[Evadne]

I would usually put a slow blow (spiral delay) fuse in line with an inductive load, but if it goes first time every time then it sounds like a transformer primary short or a duff smoothing capacitor (if it has one) or something like that. I'd take it back to the shop.

 

[reeac]

I have heard of quite a few cases where these transformers have proved unreliable. A bit late to make the comment, but why use 12 volt lighting in a building that presumably has 240volts? The standard 240 volt equipment is well developed, cheap and reliable.

 

[jimbouy]

I couldn't agree more. But see my previous comment ref SWMBO choosing looks over practicality.

Who am I to argue /forums/images/graemlins/smile.gif

I'm just the handy man!!!

 

[charles_reed]

In fairness to yourself

The 12v systems are far less thirsty than the 230v halogen and they also produce a wider spectrum of light up to a rather longer wavelength.
So for lighting connoisseurs dc is preferable.

 

[jimbouy]

Re: In fairness to yourself

So I'm a connoisseur!

Wow

 

[Anonymous]

Re: In fairness to yourself

I'm just puzzled, maybe you know the answer.....I've often wondered why the 12V halogens are popular in buildings - from first principles I can't think of any reason why a bulb with a 12V coil should be better than a bulb with a 230V coil. Are the builiding systems actually dc, or are they just 12V ac? I can't think that dc would make much difference unless you were trying to avoid the stroboscopic effect with rotating machinery. Any ideas why the manufacturers have gone down this path?

 

[ytd]

Re: In fairness to yourself

12V bulbs "boil" off less of the filament that 230V ones, so they last much longer and can run hotter, improving efficiency and the naturalness of the light produced.

Building lighting is generally 12V ac but they work just as well on dc.

Check there are no shorts on the 12V side. There is a fair bit of manufacturing tolerance in the distance between the pins and i have seen this short out the connectors once the whole thing heats up.

The tansformers are prone to going open circuit on the 230V side especailly if there is any sort of short on the 12V side.

 

[Anonymous]

Re: In fairness to yourself

Thanks, I knew there had to be a reason! They are absolutely brilliant on a yacht - I would not have conventional tungsten or fluorescent for space lighting now that I have experienced halogen.

You can buy adaptors that fit into bulkhead reading lights to convert from conventional to halogen but we find the halogens too harsh in those.

 

[TrueBlue]

incandescent vs fluorescent

Halogen lamps are super when you want a directional light for a specific area. SWMBO has one over the cooker hob so she can see what is burning, gives a sharp focused light, we also use smaller ones for reading lamps,

BUT for general space lighting you can't beat 2-D fluorescent lamps consume little energy and light the whole boat. I use 24v units from Marlec.

FWIW