Clint Jay left a comment on the Poundland GU10 lamp video saying that it glowed on just 12V. I tried it, and it does glow!
Then I tried it on lots of other GU10 LED lamps and just under half of them glowed, with one actually running at a full watt of power!
The ones that didn't work probably contain a variant of the BP3102 style chip that has a built in power supply circuit that only kick-starts at a modestly high voltage, so that probably prevents them from starting on 12V. The others tend to have more discrete circuitry that is capable of running on quite low voltages.
One lamp started quite brightly on 12V but then went out, but still drew a lot of current suggesting that its circuitry had possibly locked up.
A few of the lamps actually put out useful amounts of light at 12V, so they could theoretically be used as deliberately low level lighting with a 12V battery in the event of a long term power outage. (That should thrill the preppers.)
Then I tried it on lots of other GU10 LED lamps and just under half of them glowed, with one actually running at a full watt of power!
The ones that didn't work probably contain a variant of the BP3102 style chip that has a built in power supply circuit that only kick-starts at a modestly high voltage, so that probably prevents them from starting on 12V. The others tend to have more discrete circuitry that is capable of running on quite low voltages.
One lamp started quite brightly on 12V but then went out, but still drew a lot of current suggesting that its circuitry had possibly locked up.
A few of the lamps actually put out useful amounts of light at 12V, so they could theoretically be used as deliberately low level lighting with a 12V battery in the event of a long term power outage. (That should thrill the preppers.)
What the heck?
After seeing lots of LED lamp teardowns – And having gone all LED in my flat a few years back – I've often considered switching my lighting circuit to be fed off my 12v doorbell transformer and removing the inverters from each lamp, powering the LEDs straight off the 12v that my lighting circuit would be supplying. This'd reduce efficiency losses from having separate inverters in each lamp, and presumably improve power efficiency (And reduce consumption) considerably. 🙂
Am I correct in thinking of it in this manner (Let's be honest, there'd be nothing wrong in having a 12v lighting circuit) or is there anything – Beyond finding a new supply for my 230v~ smoke detector (Presently run from the lighting circuit) – That I'm missing here? 🙂
how hard is it to convert a GU10 led lamp to work on 12 v only? I have a 5 led GU10 lamp , took it apart it looks like it is wired in series .
three-LED Monte
I have know about this for a long time they will work on 8v 200ma I got an Asda Led G4 2.5w 240v on a 12v gel battery been running for 5 hours so far makes a good emergency light just take your 240v led and connect to car battery any way round no inverter needed 😀
wait, why does the polarity matter?
I mean, don't these PSUs first go through a first rectifier? so it shouldn't really matter which way you put em in
well… assuming they're not just using half wave single diode rectification
how about lamps with a capacitive dropper on 12V high frequency ac? Would they light as bright as on mains?
So they are AC, but only work on one polarity?
Half wave rectification would make them a seriously distorting power factor, but I suppose with luck, multiple units may end up opposing and balance out
its so cool
it's funny I was looking for 220v lamps that would work on 24v from solar cells as backup on the same wires when the power goes out.
That seems very feasible now thanks.
Nearly 100% failure rate on connecting the leads. DC sucks! 🙂
I won an(listed as) LED 3W 220V bulb for $0.36. When I tested it on my Killawat EZ at 110V here in the USA it read 0.6W. Does that sound like the proper result considering half the rated voltage was used? Should it read 1.5W ? Thanks bigclive, your videos are pretty good.
I'm just learning to have some fun with electronics/LEDs and occasionally building some very basic and crude(but relatively safe ;D ) 12V battery powered lights for fun.
My eBay, alleged 240 VAC 10W RGB floodlight (actually 4 or 5W) will turn on at around 28 VDC and you can then turn the voltage down to around 10V before it goes off.
If most or all the rooms in the house used GU10s, it would make it fairly straight forward (for an electrician) to add a switch to the lighting circuit to toggle between mains power and a 12V battery source. As the LEDs draw a fraction of the power, you wouldn't need an expensive or bulky high capacity battery either, let alone an inverter.