L.E.D lights - UK Vintage Radio Repair and Restoration Discussion Forum

vinrads · 3rd Apr 2015, 12:46 pm

I am thinking of installing some blue LED lamps , 12 volt type, my question is do the lamps have a built in bridge rectifier / what supply to use , Mick.

3rd Apr 2015, 3:26 pm

Why not plump for 240V ones, no need to select a PSU then. For example https://www.tlc-direct.co.uk/Products/MLGL8101.html

winston_1 · 3rd Apr 2015, 4:14 pm

The 12v GU5.3 types usually have rectifiers. You can run them off a transformer (but not an electronic switch mode supply used for halogens) or a DC supply.

The sticky strips do not have rectifiers and can only be run off DC.

vinrads · 3rd Apr 2015, 5:10 pm

I opted for the 12v ones , because have you heard the racket produced from the mains ones.

Herald1360 · 3rd Apr 2015, 7:00 pm

I'm sure the racket will depend on the make. Ones from Philips, Osram and the like will probably be reasonable. (Noise wise, that is.)

3rd Apr 2015, 7:04 pm

My TLC ones are very quiet, it is something I do look at when selecting stuff being a radio user. OK they where 30 quid each (I have the white ones), worth it. I do ask when buying stuff 'can I return it if it interferes with my radio'.

vinrads · 4th Apr 2015, 8:56 am

Thanks Winston. I suspected they must have a built in rect because they can be fitted either way round . so it's the 12v ones for me, Mick.

Mods. this thread can be closed thank's

Radio Wrangler · 4th Apr 2015, 10:50 am

Remember that even the 12v ones probably have a switcher in them to regulate the diode currents.

And the 'transformers' sold to power 12v lighting are usually switchers in disguise.

I've got a mix of Tesco 12v halogen replacements fed from real iron transformers, and Osram 240v bulb replacement lights and HF radio seems OK. Someone else not too close by is the problem.

David

broadgage · 4th Apr 2015, 11:18 am

If your proposed 12 volt blue LED lamps are in the standard MR16 2 pin format as used for 12 volt halogen lamps, then yes all common types do incorporate a full wave bridge rectifier and may therefore be used on DC of either polarity, or on 12 volts AC at line frequency from a copper iron transformer.

Most types wont work on the high frequency 12 volts AC that is produced by electronic "transformers" that are widely used for 12 volt halogen lamps.

The internal circuitry of these 12 volt LED lamps varies. The relatively high powered lamps intended for room lighting use a switched mode or pulse width modulation circuit so as to drive the LEDs at constant power despite variations in the supply voltage.
The lower powered lamps intended primarily for decoration often use a simple resistance dropper.

3rd Apr 2015, 12:46 pm	#1
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,764	L.E.D lights I am thinking of installing some blue LED lamps , 12 volt type, my question is do the lamps have a built in bridge rectifier / what supply to use , Mick.

3rd Apr 2015, 3:26 pm	#2
Guest Guest Posts: n/a	Re: L.E.D lights Why not plump for 240V ones, no need to select a PSU then. For example https://www.tlc-direct.co.uk/Products/MLGL8101.html

3rd Apr 2015, 4:14 pm	#3
winston_1 Hexode Join Date: Oct 2012 Location: London, UK. Posts: 499	Re: L.E.D lights The 12v GU5.3 types usually have rectifiers. You can run them off a transformer (but not an electronic switch mode supply used for halogens) or a DC supply. The sticky strips do not have rectifiers and can only be run off DC.

3rd Apr 2015, 5:10 pm	#4
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,764	Re: L.E.D lights I opted for the 12v ones , because have you heard the racket produced from the mains ones.

3rd Apr 2015, 7:00 pm	#5
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: L.E.D lights I'm sure the racket will depend on the make. Ones from Philips, Osram and the like will probably be reasonable. (Noise wise, that is.) __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

3rd Apr 2015, 7:04 pm	#6
Guest Guest Posts: n/a	Re: L.E.D lights My TLC ones are very quiet, it is something I do look at when selecting stuff being a radio user. OK they where 30 quid each (I have the white ones), worth it. I do ask when buying stuff 'can I return it if it interferes with my radio'.

4th Apr 2015, 8:56 am	#7
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,764	Re: L.E.D lights Thanks Winston. I suspected they must have a built in rect because they can be fitted either way round . so it's the 12v ones for me, Mick. Mods. this thread can be closed thank's

4th Apr 2015, 10:50 am	#8
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,901	Re: L.E.D lights Remember that even the 12v ones probably have a switcher in them to regulate the diode currents. And the 'transformers' sold to power 12v lighting are usually switchers in disguise. I've got a mix of Tesco 12v halogen replacements fed from real iron transformers, and Osram 240v bulb replacement lights and HF radio seems OK. Someone else not too close by is the problem. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

4th Apr 2015, 11:18 am	#9
broadgage Nonode Join Date: Jan 2010 Location: North Somerset, UK. Posts: 2,130	Re: L.E.D lights If your proposed 12 volt blue LED lamps are in the standard MR16 2 pin format as used for 12 volt halogen lamps, then yes all common types do incorporate a full wave bridge rectifier and may therefore be used on DC of either polarity, or on 12 volts AC at line frequency from a copper iron transformer. Most types wont work on the high frequency 12 volts AC that is produced by electronic "transformers" that are widely used for 12 volt halogen lamps. The internal circuitry of these 12 volt LED lamps varies. The relatively high powered lamps intended for room lighting use a switched mode or pulse width modulation circuit so as to drive the LEDs at constant power despite variations in the supply voltage. The lower powered lamps intended primarily for decoration often use a simple resistance dropper.