Angel Eyes.

I have just fitted a set of angel eyes to my mill, in a similar set up to the article in MEW287. The required power supply is 12 volts DC. I have 4 power supplies claiming to be 12 volt DC x 450 milliamp left over from replaced kit. All of them show 18 volts on my meter when checked without any load. I also have a multi voltage DC regulated power supply that does show the correct voltage when tested in a similar way.

I have 2 questions for the experts. 1 ,why do they show 18 volts when the label says 12 volts? 2,am I going to blow the light if I use one at the 18 voltage. I also have one marked 6 volts that shows 10 volts on the meter, but when connected to the light it is dim and flashing like a tube with a dud starter..

Keith

They are possibly built as battery chargers? Try a car flasher bulb (it wont care about 18V) as load then measure the volts.

Very common to have small DC power supplies having a much higher voltage with no load. At their rated maximum current then the voltage will drop to the specified value. They are simple cheap unregulated supplies.

Work out (or measure) the operating current for your ring light and if it is somewhere near the maximum current stated on the power supply, then you have no problem. If it is much lower, then use a dropping resistor to reduce the voltage. LEDs are not too fussy about the supply voltage.

Andrew.

I am told that the light draws 250 milliamps, so over half way to max. . I will probably light it up for a hour to test. The lights come in pairs, so I have a spare if this one blows.

Thank for your comments.

Keith

Hi all I have just purchased an Axminster ZX30M mill to replace my old 1982 Alpine although it is a lot beefier and bigger, I am hoping to find a right angled head to fit this machine can anyone point to one ? or plans to make one, really looking forward to its arrival in two days time I got a real deal of just over £1000.000 my local Axminster store decided to have a clear out of slow moving equipment, I believe it is a Sieg variant.

Peter G0KOK

There are some very cheap stabilised power supplies available from China. This one seems perfect for you application.

**LINK**

All of the ring lights I have used have had a small enclosure containing a switch mode power supply in series with the power lead. Although specified for 12V operation the ring LEDs are powered from 5V derived from this PSU and this makes them very tolerant to the input voltage from around 10V to 18V.

I repackage the SMPU in a small enclosure with a standard plug top connector to allow easy connection to standard PSUs.

It is also important to choose the largest diameter light you can source to reduce 'chuck shadowing'.

See **LINK** for more details on my versions.

Alan

Thanks for that link Mike. I have just checked with my original advertisment and it says voltage is range 12-24, so I probably do not have a problem. I will get a small regulated supply though, just in case.

Keith

Can we have a picture of your angel eyes?

I will take a picture tomorow. The lights I have do in fact have a small tubed item wired in which I now presume is a Switch Mode Power Supply. The lights are 100mm diameter.

Keith

Good luck with your LEDs. Even though low wattage, if the installation can run hot (mdf is quite a good insulator) the lifespan of the LEDs can be reduced - they like to run cool.

Have a look at LINK and LINK .

I don’t know how (or whether) yours may be affected, but I think I would have used a metal reflector rather than a wooden one.

Edited By not done it yet on 04/02/2021 19:28:24

Years ago I got hold of some BMW 'angel eyes' which were 'pre' LED and needed a driver to light them up. They woe really bright compared to LED's at the time.

Battery charger power supplies always run above stated voltages but drop closer to stated voltage when connected to their original battery with 'correct' internal resistance. The exception will be chargers for lead acid batteries which will always run closer to 14v

The old un-regulated transformer type would always develop root two x the voltage (at rated current), when no load is connected. Fact of life with a sinusoidal grid supply

I built one of these devices some years ago but found, on mine, that the business end of the cutter was always in shadow.

I added one to my mill as per the MEW article and found it OK, but even after playing about with small shades & reflectors etc found it still tended to leave the business end in shadow. Ordinary work lights tend to get in the way a bit, Some time back I found some 'goose neck' fine spotlights with a clamp, the head being quite small (say 2cm in dia and 4cm long) and a flexible stem about 250mm long - which proved perfect for getting sharp light right onto the cutter. I got these from Chas Ohlson the Swedish hardware store which has unfortunately now stopped trading in the UK, but I think their products are available now through Amazon

Regards