Any experts on low-voltage LED spa lighting?

[AussieM8]

Hi guys

I recently purchased some LED cabinet lights for my spa (online) and having some issues. They are 5 volt colour-changing LED's and before installing them in the cabinet, I have powered them up but they only light up for around 1 second. Each item has a maximum power rating of 0.6 watt and has three LED's in it. For those not familiar, the colours change by toggling the power on then off quickly.

Here is the item:


For the power source test, I've used a USB plugged into my PC and also a USB power adapter. Would they be drawing too much power and this is why they don't stay on? Looking at the date-stamp on the item, it seems they were manufactured in 2010 so is there a possibility that they are 'too old' and faulty?

Note:
The vendor is refusing to refund stating "Once electrical parts are powered up we are unable to take a return on them".

[Skepticist]

Do they work with the specified power supply/controller combination?

[gordon_s1942]

Firstly, if they eventually prove to be faulty, that crap by the Vendor claiming that once their powered up voids any return is like when I took a set of printer cartridges back as faulty and the moronic salesman said it 'was a pity I had opened the packet', like how the hell could I tell they were faulty UNTIL you try to use them???
I take it they light up briefly each time you connect them to a power source but then go out, if so to me that says the LED's are ok but maybe a capacitor (if any) in the circuit is breaking down?

LED'S as far as I understand them are no different basically to an incandescent globe with a filament, you apply the correct current/voltage and they light up and stay lit until either they fail or the power is removed.

You dont say what Voltage/Current is marked on the strip because the 5v 500 mA from the computer/charger may not be enough to run the strip properly.

[admin]

Note:
The vendor is refusing to refund stating "Once electrical parts are powered up we are unable to take a return on them".

They dont seem to know their own policy.

Its actually : "Any electrical or electronic part that shows signs of having been used or fitted in any way."

You obviously havent fitted them, and staying lit for less than a second does not consitute use in anyones book, let alone the ACCC's.

[AussieM8]

Do they work with the specified power supply/controller combination?

I initially plugged them into my spa wiring (using an existing connector from one of the other LED's) and they started flashing. This is why I was concerned they were faulty and tested with the USB power as I knew it was 5v as well.. I plan to get back into the spa cabinet tomorrow to check the voltage with a multimeter but I suspect it will be 5v as well.

[AussieM8]

Agree completely Admin

The email I received also suggested that I may be at fault if I powered them up at an incorrect voltage, so I suspect they will be trying to get out of it from that angle as well. I'm sure it will be 5v but proving this may be difficult to an online store ... I guess I can video my multimeter reading

[AussieM8]

Firstly, if they eventually prove to be faulty, that crap by the Vendor claiming that once their powered up voids any return is like when I took a set of printer cartridges back as faulty and the moronic salesman said it 'was a pity I had opened the packet', like how the hell could I tell they were faulty UNTIL you try to use them???
I take it they light up briefly each time you connect them to a power source but then go out, if so to me that says the LED's are ok but maybe a capacitor (if any) in the circuit is breaking down?

LED'S as far as I understand them are no different basically to an incandescent globe with a filament, you apply the correct current/voltage and they light up and stay lit until either they fail or the power is removed.

You dont say what Voltage/Current is marked on the strip because the 5v 500 mA from the computer/charger may not be enough to run the strip properly.

Thanks Gordon.

They are 5v - see photo:


Does this mean that the current would be 120mA (0.6W/5v)? If so, then a USB should power it OK

[gordon_s1942]

excuse my maths but wouldnt that 0.6 watts equal about the usual 500 mA which I think is the power output of the USB port and most chargers?

[AussieM8]

Really not sure mate, that's why I started this thread.

I'm going to get back into the spa wiring today and test the actual voltage, etc.

[tristen]

excuse my maths but wouldnt that 0.6 watts equal about the usual 500 mA which I think is the power output of the USB port and most chargers?

No.

W = EI therefore I = W/E

0.6/5 = .125(A) or 125(mA) as the OP has calculated correctly.

That being so, an USB supply is more than adequate to power the device. However, there is "pulsing" and there is "flashing".

It is common practice when wishing to produce increased light output form LED's, to feed them with high current "pulses". This has the effect of increased LED brightness but with a low average current drain. Peak current will vary depending on the duty cycle (on-of ratio of pulses).

It is possible that the LED lights which the OP has purchased, utilise this technique and this is upsetting the USB supply.

My advice is to power them from the correct source as mentioned by Skepticist in his post #2.

[watchdog]

excuse my maths but wouldnt that 0.6 watts equal about the usual 500 mA which I think is the power output of the USB port and most chargers?

There is no excuse for that sort of maths

[AussieM8]

My advice is to power them from the correct source as mentioned by Skepticist in his post #2.

OK, I powered them up using the spa. I also attached my multimeter to the spa light circuit and it's showing a constant voltage of close to 5v (4.93v to be exact).

As I mentioned before, the colour-change is effected by turning them off and on quickly. The existing spa lights cycle through 5 or 6 colours, followed by a gradual colour change and then a flashing colour-change. When I connect the new ones, they act differently than when I connect to USB 5v. The LED's don't fire on any of the single colours, but start to flash/flicker when on white and the steady colour change.

Does this behaviour line up with your theory that the purchased LED's are looking for a pulsing current whereas my spa has a steady 5v?

[Downunder35m]

Each light uses 120mA, so four of them are at the maximum of the USB standard.
You said they worked on your USB supply, so did you check the voltage when connected to the spa?
I assume the lights overload the power supply and won't get enough juice to function properly.
Also I have a great problem understanding the concept of the color change - are you saying every time you switch them on it changes?
A color changing LED is under 3 bucks, suitable resistor(s) are worth peanuts...
No idea why the charge you so much for the plastic around it

[Skepticist]

I'd think the only way to be certain that they are faulty is to test them with the actual power supply specified for them as there could be some means of control sourced from that supply. I wouldn't expect all the units you purchased to be identically faulty, one perhaps but not all.

They're mighty expensive as previously stated for RGB LEDs. I can get 300 of them for $20 so all the value must lie in the plastic case with these units

[AussieM8]

I'd think the only way to be certain that they are faulty is to test them with the actual power supply specified for them as there could be some means of control sourced from that supply. I wouldn't expect all the units you purchased to be identically faulty, one perhaps but not all.

Yeah, I now don't think they are faulty ... I'd say they are just not compatible with the LED lighting controller on my spa. To test this theory, I thought I might go to a spa shop and try them in another brand to see if they work there. I suspect they will unfortunately.

They're mighty expensive as previously stated for RGB LEDs. I can get 300 of them for $20 so all the value must lie in the plastic case with these units

Yeah, they seem to charge a premium for all spa accessories .. eg. for a single pop-up speaker where the parts would be lucky to be $20, you are looking at $150-$200

[AussieM8]

Each light uses 120mA, so four of them are at the maximum of the USB standard.

I was only trying one of them with a USB, so it's well within the USB power limits.

Also I have a great problem understanding the concept of the color change - are you saying every time you switch them on it changes?

Yep, that's correct. As I understand it, each LED has it's own chip so remembers the colour it was set to. If you turn them off and on (quickly), this cycles through the colours. If you turn them off and on slowly, it comes back on at the colour it was set at previously.

A color changing LED is under 3 bucks, suitable resistor(s) are worth peanuts...No idea why the charge you so much for the plastic around it

Totally agree ... If they won't take a return, I think I'll just use the plastic enclosures and buy some standard LED's to replace the ones it came with !!

[tristen]

...Does this behaviour line up with your theory that the purchased LED's are looking for a pulsing current whereas my spa has a steady 5v?

Without further relevant information all is conjecture at this point.

Can you point us to a specification sheet for:

1/. The new LED lights.

2/. The recommended controller for the new LED lights.

3/. The existing spa lights.

4/. The existing controller.

[AussieM8]

Unfortunately, I don't have any of that information Tristen

I'll just have to put this down to experience and in future, not assume that all spa lighting is compatible.

[tristen]

Unfortunately, I don't have any of that information Tristen

Thanks AussieM8.

I have had a look for specifications for the LED light you have bought, but was unsuccessful.

The first rule for successful faultfinding is, proceed from the known to the unknown.

Unfortunately, at this stage, we don't have enough relevant information to enable us to proceed further.

I'll just have to put this down to experience and in future, not assume that all spa lighting is compatible.

Agreed.

[AussieM8]

Thought I would report back ... I contacted the manufacturer (in China) and they have been amazing. They ended up sending me two replacement lights (paying all costs, including DHL delivery) and they work perfectly.

Looks like the ones I ordered originally must have been a bad batch