Checking LED Anchor Light

[guyrj33]

Originally Posted by SteveSails

YES, a diode conducts current in one direction only, BUT, your meter is not connected directly to the LED diode. There are other things in there that the diode that emits light needs to work and not burn out in a single flash of glory. See my previous post.

Capt. Don Good call on the light sensor, had the same issue once and it took awhile for the head slap to kick in.

SteveSails gets my vote for best answer.
A LED bulb is a complex solid state circuit.

[SteveSails]

OK you asked for it.

Two transistors are in a bar enjoying their beer (bet you didn't know transistors like beer), anyway, one says to the other "How was that date you had last night?" the other says "Not going to work out, I think she's bipolar."

A week later the same transistors were in the bar, "So how was that date last night?" "Much better, her father met me at the gate with a Schottcky barrier but I had the potential to get over that. She has a real hard luck story, grew up in an integrated circuit, her brother lost a leg in the war but found work as a diode, and her sister went into thermal runaway with an IGBT group. All in all though she's a real darlington although I must admit to being positively biased."

Yes, there are some bad puns in there. Drum thump please.

[P3sailor]

To simplify things a diode is basically an electrical check valve, i.e., open in one direction closed in the other. Now, I've installed some LED lighting in a vessel that included a warning that stated if wired "backwards" damage to the diode could or may occur. Food for Thought

[Montanan]

Useful Wiki reference:
https://en.wikipedia.org/wiki/LED_circuit


Snipet there of:

"Most LEDs have low reverse breakdown voltage ratings, so they will also be damaged by an applied reverse voltage above this threshold. The cause of damage is overcurrent resulting from the diode breakdown, not the voltage itself. LEDs driven directly from an AC supply of more than the reverse breakdown voltage may be protected by placing a diode (or another LED) in inverse parallel.

The manufacturer will normally advise how to determine the polarity of the LED in the product datasheet."

[sailorboy1]

People I know what diode is (it’s an electrical check valve)

I tested the circuit with my diode meter and got an open regardless of which probes I put where. Guess I’ll just reverse the wires and see what happens

[hamburking]

Try testing it at night, when its dark.

[kmacdonald]

Originally Posted by sailorboy1

People I know what diode is (it’s an electrical check valve)

I tested the circuit with my diode meter and got an open regardless of which probes I put where. Guess I’ll just reverse the wires and see what happens

Good idea!

[kmacdonald]

Originally Posted by hamburking

Try testing it at night, when its dark.

So he can see the sparks?

[P3sailor]

That should pretty much answer the question. If the diode check indicates an open regardless of polarity I would have to say the light is bad, unless, of course you have an open somewhere in the circuit. Still, as some have suggested, try reversing the wiring to see if the light works, can't hurt.

[billgewater]

I have a similar problem and may have to climb the stick and do something intelligent (to make up for previous non testing idiocy).
I have noted that the LED sectored light which is now an LED causes my TV antenna to go spasmo and stop working.
So, unless I have another brain storm, I am going to install the original filament bulb back into the assembly.
It means I can watch TV at mooring. I just can't watch TV with the sectored LED light on.
The theory being that I should not be sailing at night and watching TV at the same time!

LED lights are not as smart as we think. Plus they are expensive. Electrickery.
Here is a trick my grandfather showed me. Given a fused filament bulb, see if the tungsten wires inside are still hanging. With power connected, move the bulb around until the hanging wires touch. They may actually fuse at contact, giving the bulb a possible second life. It may be short, it probably won't work as air may have entered the bulb, but my grandfather was Scottish so he took great pleasure with any such success.

[SV Bacchus]

I had a similar issue with an LED in the Red/Green bow light. Whew, much simpler than climbing the mast.

Turns out when I inserted the new bulb it apparently didn't make good contact with the contacts. I took it out, a little sandpaper on the contacts and BOOM, it works like a champ! The seal seems to be "going" on the housing so I probably need to replace the fixture. I have a temp fix of taping the seam where the halves of the housing join, not gonna last.

[sailalibi]

My tricolor led photo cell must have failed. While the anchor light switch is always on I must cycle it after dark to turn on the anchor light! Thoughts?

[skipmac]

Originally Posted by guyrj33

A LED bulb is a complex solid state circuit.

Actually a diode or LED is perhaps the simplest solid state circuit. Essentially a P-N junction with wire connections (anode and cathode) that emits light from the P region. So essentially a single, simple device.

This of course is a very simplistic description of a diode but that's the basics.

Sorry I couldn't resist dredging up the details of my long ago courses in solid state design and fabrication.

[skipmac]

Originally Posted by sailorboy1

People I know what diode is (it’s an electrical check valve)

I tested the circuit with my diode meter and got an open regardless of which probes I put where. Guess I’ll just reverse the wires and see what happens

If you got an open in both directions with the diode test function on a meter then I'm guessing one of two problems.

1. Bad connection. In the process of moving stuff around a wire or something came loose.

2. Diode fried. Since diodes are pretty reliable I'm guessing #1 is more likely.

But a question, does your light have an auto on photo cell in the circuit?

[Montanan]

Originally Posted by billgewater

I have a similar problem and may have to climb the stick and do something intelligent (to make up for previous non testing idiocy).
I have noted that the LED sectored light which is now an LED causes my TV antenna to go spasmo and stop working.
So, unless I have another brain storm, I am going to install the original filament bulb back into the assembly.
It means I can watch TV at mooring. I just can't watch TV with the sectored LED light on.
The theory being that I should not be sailing at night and watching TV at the same time!

LED lights are not as smart as we think. Plus they are expensive. Electrickery.
Here is a trick my grandfather showed me. Given a fused filament bulb, see if the tungsten wires inside are still hanging. With power connected, move the bulb around until the hanging wires touch. They may actually fuse at contact, giving the bulb a possible second life. It may be short, it probably won't work as air may have entered the bulb, but my grandfather was Scottish so he took great pleasure with any such success.

Indeed LED lights commonly interfere with television and radio reception. The devices are often not well shielded. Utilizing coaxial shielded wire can help reduce interference. Adding EMI filters also can improve results, perhaps as simple as the snap on ferrite core chokes. An example, there being many such devices of various types. https://www.amazon.com/VSKEY-Anti-In...9PZXG2ABQGHDA6