My daughter has some under cupboard lights - about 3inch diameter reflectors with a G4 bulb.
They fail frequently and I would like your advice on LED replacements.
LED Bulbs?
New fittings that would work of existing transformer????
Replace the lot with LED Tape? (However, this would take 3 separate lengths)?
The general impression I get is that G4 are too small to allow LEDs to cool properly, so they would fail frequently too ...
I have recently second fixed a kitchens electrics and the customer supplied the lights. They were led 230V (so you can bin the transformer) and I guess very similar in style to the ones your daughter has.
I am sure that they were called Robus Captain.
Where are you buying your spares from? I've found shed bought lamps seem to be of pretty poor quality life wise, so only buy from TLC these days.
IIRC, G4 is one of those very small lamps that can't be replaced with LED successfully. So might be better to find a complete LED fitting.
I assume you mean a G4 capsule used sideways, and not a reflector lamp. They do exist but are not easy to find. Kosnic produced them for a year and stopped because too little demand. Then Verbatin produced them for a year and stopped because too little demand.
CPC have a no-name one now:
Check they will fit. Note you might be able to remove any reflector because these LEDs don't need it.
If it's an old magnetic transformer, yes. If it's an electronic transformer, probably no because they won't draw enough power to keep the transformer running. If you have several of them, you might find they will work if all run from a single transformer to generate enough load for it.
I have been very impressed with LED tape for under cupboard lights... If you buy a long length it can be cut into shorter sections.
I guess my purpose would need 3 drivers.
I had one of those desk lights with the transformer in the base which used a G4. Because it was heavily used, lamps seem to needed replacement frequently. Found an LED G4 replacement on Ebay - no idea of brand, but wasn't cheap. Light from it was pathetic. So went back to halogen.
Couple of years ago, Lidl had LED desk lamps of about the same sort of size. Multiple warm white LEDs. That's been just fine - and also barely gets warm.
I bought something similar from Aldi about a year or so ago. It uses a
20vdc wallwart to power its 4 watt's worth of LEDs in the lamp head mounted on a couple of re-purposed telescopic aerials (same idea as the 12v 20W halogen bedside table lamp my wife uses). The base contains a dense lump of concrete ballast with cut-outs for the DC jack socket and the push-button on/off switch.One night, I noticed that I could get a dim glow from the LED array by touching one of the telescopic arms, the power most obviously, was coming from the leakage current of the wallwart's EMI filter capacitor circuit treating the DC 0v rail as a 'ground rail' despite the complete lack of a metallic 'Earth Pin' (ie, the hi-Z half mains supply source of 'tingle current' was providing just enough illumination to allow me to tell the time from a Casio analogue display bedside alarm clock).
This gave me the idea of extending the lamp's function by wiring a 100K resistor across the switch contacts so that it could also act as a very dim 'night light' (just a little bit brighter than it was whilst lit by leakage current alone) when switched off whilst still connected to its wallwart power source[1] thus rather neatly capitalising on a key benefit of LED over incandescent filament lamp technology, that of producing very low levels of illumination with virtually no colour shift at current levels so insanely low that not even the lowest wattage filament lamps could produce light in the visible spectrum (infra-red, yes; Visible light? No chance!).
[1] As is my usual practice with anything supplied with a wallwart PSU (and mains voltage LED lamps), I check its operating consumption and, more importantly for stuff that places its on/off switch *after* the output of its wallwart PSU, its no-load power consumption.I use a venerable Metrawatt analogue wattmeter for these tests since, with the aid of a jeweler's loupe and the mirror backed 100W scale, I can reliably interpolate down to quarter of a watt on sub 10 watt loads and detect standby power drain levels down to a tenth of a watt or less[2].
In this case, the standby idle consumption proved to be undetectable, meaning it was very likely less than 50mW. Improvements in standby consumption efficiencies for modern smpsu wallwarts are showing up even in those 5v 1A USB wallwarts that you can now purchase from Poundland.
[2] TBH, this just an educated guesstimate. I have yet to fabricate the high voltage 576K ohm 100mW test load resistor required to see the actual effect on the displacement of the needle from its zero set point with such a low load.Since it's a given that I'll see a definite twitch[3] when plugging a wallwart in to the test socket due to the inrush charging current of the HT rectifier pack smoothing cap or caps, I have to look for a deflection from a steady state idle consumption reading that drops back down to the zero point on the scale when I switch the wallwart off at (or unplug it from) the mains socket.
[3] This is where an analogue wattmeter scores over the cheap 'n' cheerful digital 'energy consumption meter'. It can do what no fancy digital wattmeter can; it can show transient readings such as even the most modest of inrush currents exhibited by low power DC voltage output wallwarts as well as variations too small to be resolved on a digital display limited to a resolution of a tenth of a watt at best. :-)HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.