One for the electronics experts in the Collective.

[slim_boy_fat]

If a person wanted to instal one [or more, in series I think] of these

https://www.banggood.com/10W-Warm-P...69.html?rmmds=myorder&ID=233&cur_warehouse=CN into this

would a redundant phone charger be up to the job, or are some additional [safety related] gubbins be needed.

I've tested one of the LEDs using 12DC off my electrolysis setup and it shone brightly - as I'd hoped.

I have a number of these small phone/torch/satnav etc chargers kicking about. I just want it to 'glow' from the inside, not act as a 'reading'/task etc lamp.

 

[Hood]

Should be as safe as anything Chinese and Electrical can be

 

[Parm]

Looking at the info on the LED it states forward current of 1050 mAmps, plus LED needs 12v

Most phone chargers are 5v at 1000 - 2000 mAmps

Your better off getting a new power supply, a quick google gives

https://www.amazon.co.uk/Morza-Tran...ocphy=9045888&hvtargid=pla-762948341224&psc=1

Search around John, they can be had for less

edit: plus what @Hood says, I wouldn't trust a phone charger for anything else. not worth the agro for a few quid

 

[Cyberprog]

As long as it's a DC supply, there's no real need for anything further safety wise. Low voltage, low current.

 

[sako243]

OK I'll try to keep this relatively straightforward


LEDs are current controlled devices - the more current the brighter the LED. However they require a minimum voltage in order to work - the Forward Voltage (which is omitted from that "datasheet" - but we can assume that it's 9ish Volts) must be met. So feed that LED anything less than 9V and it won't even light up, even if you have 100A behind it. If you chain multiple LEDs (e.g. 10 of them) then you need 90V from one end to the other.

If you want to control the brightness then you need to regulate the current rather than the voltage - which is usually done via pulse width modulation (PWM), i.e. it chops the voltage on-and-off rapidly (faster than the eye can detect) which will result in a smaller average current passing through the device.

 

[eLuSiVeMiTe]

I never throw old chargers and wall wart psu's away. Always come in handy.


Something like that maybe.

 

[slim_boy_fat]

OK I'll try to keep this relatively straightforward

Exactly what I need when it comes to elektrickery

Thanks lads

@Parm I have a number of chargers similar to those linked by yourself & @eLuSiVeMiTe , even some 'reputable' names - will have a study of their specs tomorrow and see what's might be suitable.

If I wired [say] 2 in series, I assume the power requirement(s) would be the same? As I said, a soft, gentle glow is the aim. It'll also depend on the opacity of the shell and/or the placement of the LEDs inside. Much experimentation ahead.

Be a chance to try my £9.99 Lidl soldering station too - every day a learning experience, eh?

 

[sako243]

If I wired [say] 2 in series, I assume the power requirement(s) would be the same? As I said, a soft, gentle glow is the aim. It'll also depend on the opacity of the shell and/or the placement of the LEDs inside. Much experimentation ahead.

If I understood what you're asking, no.

If your power supply can deliver the current then they'll be maximum brightness. The cheap simple way to regulate brightness is to use a current limiting resistor. This is where we need to know the forward voltage.

If you have one LED with say a 9V forward voltage from a 12V supply then there'll be 3V across the resistor. If you wanted to limit current to 500mA then V=IR rearranged puts R=3/0.5 = 6 Ohms. But you'll want to pay attention to power rating because the power dissipated in the resistor will be P=I*I*R=1.5W.

So you'll have a 1.5W heater wired in series too. Perhaps useful for Scotland but a more efficient manner then use an LED driver / constant current source.

 

[ibrooks]

There's a crate of the things at work that I'm likely to be told to throw in a skip. 9v from memory.

The skip may be MINI or Discovery shaped when the day comes.

 

[eddie49]

A 10 Watt LED that draws 1050mA will have 9.52 volts across it ( 10 / 1.05 ).
I'd suggest finding a 240v -> 12v 2A power supply.
A 10 Watt LED will be very bright - it is equivalent to a 100 watt incandescent bulb - and so you will need a dimmer.
This gadget is a PWM dimmer:

https://www.ebay.co.uk/itm/Brightne...Single-Color-LED-Strip-DC-12V-8A/163783478527

 

[CoValent]

I just want it to 'glow' from the inside, not act as a 'reading'/task etc lamp.

These might be a better option for you in that case: https://www.diy.com/departments/diall-g4-90lm-led-capsule-light-bulb-pack-of-2/1324490_BQ.prd

They have a built in inverter, and seem (from my tests) to be happy to maintain a steady light output at any voltage from 8 to 16V. They don't care whether it's a DC or AC supply, so any old transformer/adapter in the appropriate voltage range will work.

 

[rtcosic]

A 10 Watt LED that draws 1050mA will have 9.52 volts across it ( 10 / 1.05 ).
I'd suggest finding a 240v -> 12v 2A power supply.
A 10 Watt LED will be very bright - it is equivalent to a 100 watt incandescent bulb - and so you will need a dimmer.
This gadget is a PWM dimmer:

https://www.ebay.co.uk/itm/Brightne...Single-Color-LED-Strip-DC-12V-8A/163783478527

Hang on a minute there, am I missing something??

That £2.38 little widget is a PWM that can handle 8 amps at 12 volts??

So I can replace my ugly bulb box (resistance box) current 'controller' on the output of my 240 V AC > 12 V DC 8 amp power supply liberated from an ancient PC that I use for electrocleaning and electroplating??

Edit:

And this one will handle 30 amps for £5.23!

Edit, edit:

or £4.69 even!

Can I put 2 in parallel and manage 60 amps ? (carefully!)

 

[WorkshopChris]

Hang on a minute there, am I missing something??

That £2.38 little widget is a PWM that can handle 8 amps at 12 volts??

So I can replace my ugly bulb box (resistance box) current 'controller' on the output of my 240 V AC > 12 V DC 8 amp power supply liberated from an ancient PC that I use for electrocleaning and electroplating??

################
Can I put 2 in parallel and manage 60 amps ? (carefully!)

Not really as a PWM is just a very fast switch varying the time circuit is either on or off, so won't limit current as such and to link 2 you would need to find a way to synchronize the two and set one as master and one as a slave in basic terms.
https://learn.sparkfun.com/tutorials/pulse-width-modulation/all

 

[rtcosic]

Not really as a PWM is just a very fast switch varying the time circuit is either on or off, so won't limit current as such and to link 2 you would need to find a way to synchronize the two and set one as master and one as a slave in basic terms.
https://learn.sparkfun.com/tutorials/pulse-width-modulation/all

Thank you for that.

Somehow I knew it couldn't be that easy.

I can cope with bulbs and wires but when the invisible imps disappear into their variously shaped hutches I get confused. Can't be doing with AC stuff beyond incandescent bulbs either.

Mental block sets in.

I'll study the link you sent, but I fear brain pain.

Edit. I think I'm getting it. Cycle the LEDs just fast enough for the brain not to notice = dimmest setting. Increase the proportion of the time the LED is on and the brain integrates the light output and sees this as brighter. So it's more a case of exploiting the brain's capabilities/limitations as with film and TVs screens.

 

[Morrisman]

I never throw old chargers and wall wart psu's away. Always come in handy.

Me too, and thus I have about 26 of them, in various boxes around the garage and lofts....all going to be used.... one day....

 

[slim_boy_fat]

These might be a better option for you in that case: https://www.diy.com/departments/diall-g4-90lm-led-capsule-light-bulb-pack-of-2/1324490_BQ.prd

They have a built in inverter, and seem (from my tests) to be happy to maintain a steady light output at any voltage from 8 to 16V. They don't care whether it's a DC or AC supply, so any old transformer/adapter in the appropriate voltage range will work.

Those look to be a good idea/solution, but although they're on offer at £1 for a pair the nearest B&Q is 40 miles away and they're not available to order online. Ah, well.......

 

[gerrymoore]

Slim Boy ..why don't you use 'ordinary' leds that take hardly any currrent (20ma or so) and can be easily controlled for brightness even with a battery supply ... in fact ....just remembered..... I've got some 3 colour leds that change colours automatically and use very little power ...pm me your address and I'll send you a few... Gerry

 

[eSCHEn]

Just seen this slim. I've bought quite a lot of the exact one and similar units you show in the past for various projects.

They're cheap and work bright enough. Being current-driven devices you need to restrict the amps getting in or else they just burn as bright as possible with a really reduced lifespan. I grabbed some fixed 700ma (IIRC) affairs to do the job, also banggood.

I probably have some of both of them about the parish if you want any. You will still need a 12VDC supply though - 1A is more than enough to do one bulb with headroom (W=AV, 10 = ?.12, therefore 10/12 = A = 0.83A).

Edit - actually thinking about it, this is not going to glow. It will be VERY bright. I bought them to use as an upgrade for an Audi A6 reverse light (non-existent) and one of these bulbs is the same as a good level of light for reversing.

I think you might have more luck with a wee SMD LED on the end of a old Nokia wall wart. 3.7V and ~300mA IIRC- that's right in the ballpark of a "raw" LED.

 

[RaceDiagnostics]

It will need a big heatsink on the back or it will burn out quick if run at full power.

 

[daedalusminos]

From your first post you just want some ambient light just to illuminate the inside of the shell...might be quite nice with one (or two) of those flickering candle LEDs

https://www.kitronik.co.uk/3590-yellow-candle-5mm-water-clear-led-30deg-5800mcd.html