LED lighting , mains or LV

[foxhole]

Looking as led strips behind coving for my lounge, was favouring mains as seem simpler with no bulky drivers needed and longer strips can be used but then found mains only comes in complete 1m strips and cannot be cut to suit wall length. Does anyone know if this applies to all mains led strips [have only checked out a couple of web sites selling mains led's].

 

[bernardgreen]

was favouring mains as seem simpler with no bulky drivers

There has to be a driver ( or DC power supply ) somewhere in the system as LED elements require a controlled DC current for proper operation. Many strips use multiple groups of three LED elements and a current limiting resistor fed by 12 volts DC

 

[winston1]

Mains is LV. One assumes you mean ELV, but best to state the voltage.

 

[JohnW2]

Mains is LV. One assumes you mean ELV, but best to state the voltage.

I thought we had established that ELV, as well as 'mains', is LV.

However, as you say, these arbitrary voltage bands are silly, since what one needs to know is the actual voltage.

 

[foxhole]

edit

 

[foxhole]

Mains is LV. One assumes you mean ELV, but best to state the voltage.

220volt as against 12volt. 220v use a rectifier cable, while 12volt required a driver.

 

[JohnW2]

220volt as against 12volt. 220v use a rectifier cable, while 12volt required a driver.

What do you mean by a "rectifier cable"?

For the record, the 'nominal' mains voltage in the UK is 230V (with a 'permitted range' of 216.2V - 253V), although, in practice, the majority of people get around 240V.

Kind Regards, John

 

[foxhole]

What do you mean by a "rectifier cable"?

For the record, the 'nominal' mains voltage in the UK is 230V (with a 'permitted range' of 216.2V - 253V), although, in practice, the majority of people get around 240V.

Kind Regards, John

http://www.ledkia.com/uk/buy-custom...h0bRVLi9-Tz7e22btYoIf2BgFTTdTLBQaAj4yEALw_wcB

 

[JohnW2]

http://www.ledkia.com/uk/buy-custom...h0bRVLi9-Tz7e22btYoIf2BgFTTdTLBQaAj4yEALw_wcB

OK, fair enough. Although they say that use of the "rectifier cable" means that there is "no need for a power supply", it appears that what they are calling a rectifier cable is, in fact, a power supply (with a mains plug on one end of the cable and a connector for the LED strip on the other end)!

Kind Regards, John

 

[ban-all-sheds]

Mains is LV.

So is 12V.

 

[foxhole]

So is 12V.

Thank you but that has been established, would just prefer a simple reply without all the petty squabbling which seems to accompany any post in the electric forum.

 

[ericmark]

A SMD 5050 uses about 20 mA the voltage varies with colour, but it would seem reasonable to have 60 LED's per meter with a resistor all in series and run each meter on the 230 volt supply, which would mean all that is required is a rectifier in the cable as stated, and the strip could likely be cut at each meter.

Not sure I like the idea of using a resistor likely it would get rather hot, most 230 volt units use a capacitor to limit current, I think one has to look at LED's in two separate lights, one as decoration in which case being economic to run does not really matter all they do is look nice, the second is to light an area in which case lumen per watt matters.

Best lumen per watt is around 100 which is typical for tubes to replace fluorescent, have to be good as fluorescent with a HF ballast is around the 95 lumen per watt so unless it uses a proper switch mode driver they will not beat the fluorescent, however the folded tube compact fluorescent used in bulb form to replace the tungsten bulbs were rather poor, they were down to around 45 lumen per watt, so produce a LED bulb at 75 watt per lumen and it is still better than what it replaces and can be dimmed because the driver is so basic.

Now with the stick on strip is can drop as low as 20 lumen per watt, after all in the main only for decoration.

Now with a proper driver you can get the full 100 lumen per watt for LED strips, but care is required.

 

[foxhole]

A SMD 5050 uses about 20 mA the voltage varies with colour, but it would seem reasonable to have 60 LED's per meter with a resistor all in series and run each meter on the 230 volt supply, which would mean all that is required is a rectifier in the cable as stated, and the strip could likely be cut at each meter.

Not sure I like the idea of using a resistor likely it would get rather hot, most 230 volt units use a capacitor to limit current, I think one has to look at LED's in two separate lights, one as decoration in which case being economic to run does not really matter all they do is look nice, the second is to light an area in which case lumen per watt matters.

Best lumen per watt is around 100 which is typical for tubes to replace fluorescent, have to be good as fluorescent with a HF ballast is around the 95 lumen per watt so unless it uses a proper switch mode driver they will not beat the fluorescent, however the folded tube compact fluorescent used in bulb form to replace the tungsten bulbs were rather poor, they were down to around 45 lumen per watt, so produce a LED bulb at 75 watt per lumen and it is still better than what it replaces and can be dimmed because the driver is so basic.

Now with the stick on strip is can drop as low as 20 lumen per watt, after all in the main only for decoration.

Now with a proper driver you can get the full 100 lumen per watt for LED strips, but care is required.

All pretty superfluous to my question.

 

[flameport]

it appears that what they are calling a rectifier cable is, in fact, a power supply

It's accurately named, it's just a bridge rectifier in a plastic box. Output is rectified mains, and each 1m piece of the strip operates at that voltage, containing only resistors and a number of LEDs in series.
The rectified mains is carried on two conductors which run the entire length of the 1m strip, allowing additional strips to be connected at the end, or longer strips to be cut at 1m intervals as required.

 

[winston1]

All pretty superfluous to my question.

The answer to your question is "probably".