Thry are diodes. Diodes only pass current in one direction. They will, of course, have a maximum reverse voltage which they can accommodate. They also have a maximum current rating, beyond which they will overheat and thermally run away.

Does that help?

Edited By not done it yet on 04/03/2022 10:34:54

Get an AAA or AA battery and briefly touch the LED ring leads onto the battery, red one end, white on the other.

Whichever way round the LED lights, the lead on the top of the battery is the positive, the lead on the flat bottom of the battery the negative.

With a 1.5V AA/AAA battery, you will not do any harm connecting it the wrong way round for a few seconds.

Edit: oh, hang on, just noticed the bit about the black in-line regulators. You won't get 1.5V through those, so will need to desolder or piggyback directly onto the LED rings from your AA/AAA battery with some spare wire.

The in-line regulators are very odd, not seen that before. Unless you have test gear, and not knowing anything about the white brick's quality or provenance, you should probably keep the black regulators in circuit in the final build.

I notice that the white brick's 12V output has a black lead on the +ve and a red lead on the -ve, so you are wise to be cautious. 

Edited By John Doe 2 on 04/03/2022 11:27:40

Don't assume anything …. Why not use a Multi-Meter to measure the voltage on the LED contacts …. It will read positive one way (The Red +ve lead will be on the positive LED terminal) and negative the other

Forward drop for white LEDs is generally 3-4V, plus a drop across a series resistor, makes 6V about right.

Andrew

The Angel Eyes are marked (although not too clearly) + & –

Robert Butler

LED’s in the ring must be connected in series, therefore required voltage is higher than, let’s say, 3.3 Volts.

You read 12V on the output of the “power supply”.

Be careful and stay save. I would place the tiny white box with that tiny PCB and CE-mark on it in an earthed box and still then you can not be sure that 230V will never escape from that. Primary and secondary tracks on that tiny PCB are not far away from each other I expect.

That may depend on the particular white LED. I routinely test them with a 3 volt lithium coin cell, and I have a string of battery operated white LEDs (from Ikea) which run off 3 volts.

George

Sorry to confuse John.

The device in the black box that hangs off the ring light is a switching regulator. It chops the incoming DC from the car electrics and transforms it down to the voltage required by the ring. Being a switching regulator it is more efficient and there is less heat created than there would be using a linear regulator.

Here is a link to my blog showing the design. which shows the Fusion model and the offset nature. The trough is for the wiring connection to the ring. The ring gets hot glued in place and the trough filled to act as a cable clamp.

The three tapped holes are for nylon mounting screws. These holes and threads are modelled in the 3D print.

I usually stick aluminium foil on the lower surface using double sided tape. This increases the reflectivity.

I also replace the supplied black box with a 3D printed larger size version which has a 2.1mm DC socket for the external supply. I also glue a magnet to this box so it can be latched onto adjacent metalwork.

I hope that gives you some help.

Kind regards

Alan

My angel eyes appear to consist of lots of sets of 3 LEDs each set with its own resistor, so you'd need quite a bit more than a AA battery. However mine doesn't look exactly the same as the OP's

Been following this with interest John, looking forward to the first trial!