Diode for Anchor/Steaming Light???

[stormalong]

Originally Posted by sailinglegend

The only time you really needs diodes is when a compass light needs to be fed from the Running lights or the Tricolour lights.

My new boat compass light was initially wired from the Running lights so when we started sailing and switched to the Tricolour the compass light failed. Rewiring the compass light via diodes from both lighting circuits is a simply solution.

This is almost exactly the same as your use of diodes. Two possible sources of power to one light. Only difference is which light is being driven.

[mvweebles]

Wow, leave a thread for a couple days.....Not sure what the chatter is. Diodes have been used for a very long time to control current direction. My questions was on sizing.

Goal here was indeed to make it so when the switch labeled "Running Lights" was activated, the all-around and the side lights illuminated. When the switch labeled "Anchor Light" is activated, only the all-around light is activated. What I want to avoid is "hey honey, flip the two switches that say "anchor light" and "side lights." I know that will work, but it's a bit of a kluge to me. In a perfect world, would be a rotary switch labeled Off-Anchor-Steam (plus Sail if applicable).

[goboatingnow]

I said at the start anything from the 1N5xxx series diodes will likely do.

[williampagano]

Perco has a push pull switching from nav to anchor lights. Not too complicated.

[EngNate]

What you want is an industry standard part# 1N5400. Unfortunately, local electronics stores are about extinct, and shipping is going to be 10X the part price, which is well under $1. I suggest www.allelectronics.com because they have low shipping, no minimum, and they sell a lot of surplus/hobbyist/experimenter parts and supplies and you'll likely find other useful items.

Also, you can use a DPDT switch and not need a diode.

[betwys1]

Originally Posted by mvweebles

I have a 36-foot powerboat with 12-volt systems. Note, regulations permit a single all-around steaming light for vessels under power below 12-meters (39-feet).

I would like to use a single all-around light as both anchor and steaming light. Occurs to me a diode of some sort will permit this - see the attached diagram.

QUESTIONS:

1. Am I missing anything here?
2. Assuming I'm on right track, any specific recommendations for Diode (URL would be great)?

Thanks in advance -

Attachment 257826

There is an embarrassment of diodes at 25 cents on up past $5. You have not specified max current, so I looked up a 10 amp, 1000 Volt reverse volts diode. Here one suitable to the task - $6 but you get ten of them
https://tinyurl.com/4jdzw4v5
...or how about a super hardened version like this one:
https://tinyurl.com/52z7t3xy
In a can, with four diodes connected as a bridge, so you need to know what you are doing (slightly) : of the four terminals, identify a ~ (AC) and a + (plus) : the plus is the cathode (where the band usually is) or if it fails choose the OTHER ~ to the same plus. Or if THAT fails connect ~ and - (minus) The minus is the anode, the ~ (AC) is the cathode, or if THAT fails connect the OTHER ~ and the electrode marked minus, the ~ (AC) electrode is the Cathode.

Now putting my engineer hat back on, you probably realise that a one pole center off, change over switch can be arranged to select either three lights together, or one light, or no lights on just one switch. The wiring for it is trivial, but I won't draw it unless you like the idea.