Halogen Lamp as Power Supply? - Electronic Circuits Projects Diagrams Free

grrr_arrghh · 13th May 2004, 08:14 PM

Hi

I have one of these halogen lamps (or something similar) and was wondering about the power supply. Bassically, there is a power supply in the base (transformer etc) and the bulb in the top is supplied by the two metal 'antenae'. The supply can supply 12v, 20W (which by my calculations is about 1.6A...).

The lamp costs about £3.50. A 12v power supply, that can supply 1.6Amps, for £3.50 seems like quite a good deal to me (wall-wort style PSUs cost around £15-20)

What does anyone think?

Oh, also, I'm not sure whether the 12v output is AC or DC (my multimeter is completely stuffed), but it doesn't make that much difference.

Tim.

ante · 13th May 2004, 08:36 PM

Tim,

The IKEA lamp just contain a transformer, it’s AC feeding the halogen bulb. But it’s a good start for building a PSU. If you have a junkbox containing a bridge rectifier some caps and so on you will soon reach your goal.

Ante :roll:

grrr_arrghh · 13th May 2004, 09:51 PM

seriously? all thats in there is a transformer? £3.50 for a transformer is not such a good deal after all!!

thanks alot for stopping me from wasting my time!

btw, any idea what kind of transformer it would be?

Thanks again

Tim

ante · 14th May 2004, 06:41 AM

Tim,

My guess is it’s a good one that can take continius load. But, you know what; the founder of IKEA Ingvar Kamprad is the only guy in the world richer than Bill Gates!!!!

Ante :roll:

zevon8 · 14th May 2004, 11:42 PM

you can use one, but three things come to mind: 1 ,generally they are pretty poor transformers, very high core losses, they will draw appreciable power with no load, 2 the physical shape is designed around the case they go in, often round, etc, and hard to mount other than in the lamp case and this physical restraint usually contributes to problem # 1, problem 3 is that they are most likely what is called Class 2 - they have a fusing wire built into the primary winding that will open circuit on overload. If you short the output winding or overload it, the link opens and the transformer is a paperweight. i have seen outputs from these devices that are into core saturation, full of harmonics, not good either.

basically they are designed to fulfill their purpose an nothing else.

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13th May 2004, 08:14 PM	(permalink)
grrr_arrghh	Halogen Lamp as Power Supply? Hi I have one of these halogen lamps (or something similar) and was wondering about the power supply. Bassically, there is a power supply in the base (transformer etc) and the bulb in the top is supplied by the two metal 'antenae'. The supply can supply 12v, 20W (which by my calculations is about 1.6A...). The lamp costs about £3.50. A 12v power supply, that can supply 1.6Amps, for £3.50 seems like quite a good deal to me (wall-wort style PSUs cost around £15-20) What does anyone think? Oh, also, I'm not sure whether the 12v output is AC or DC (my multimeter is completely stuffed), but it doesn't make that much difference. Tim.

13th May 2004, 08:36 PM	(permalink)
ante	Tim, The IKEA lamp just contain a transformer, it’s AC feeding the halogen bulb. But it’s a good start for building a PSU. If you have a junkbox containing a bridge rectifier some caps and so on you will soon reach your goal. Ante :roll:

13th May 2004, 09:51 PM	(permalink)
grrr_arrghh	seriously? all thats in there is a transformer? £3.50 for a transformer is not such a good deal after all!! thanks alot for stopping me from wasting my time! btw, any idea what kind of transformer it would be? Thanks again Tim

14th May 2004, 06:41 AM	(permalink)
ante	Tim, My guess is it’s a good one that can take continius load. But, you know what; the founder of IKEA Ingvar Kamprad is the only guy in the world richer than Bill Gates!!!! Ante :roll:

14th May 2004, 11:42 PM	(permalink)
zevon8	you can use one, but three things come to mind: 1 ,generally they are pretty poor transformers, very high core losses, they will draw appreciable power with no load, 2 the physical shape is designed around the case they go in, often round, etc, and hard to mount other than in the lamp case and this physical restraint usually contributes to problem # 1, problem 3 is that they are most likely what is called Class 2 - they have a fusing wire built into the primary winding that will open circuit on overload. If you short the output winding or overload it, the link opens and the transformer is a paperweight. i have seen outputs from these devices that are into core saturation, full of harmonics, not good either. basically they are designed to fulfill their purpose an nothing else.