what diode for running anchor light switch

[Outobie]

Hello

I'm rewiring my helm switches and need to figure out:

1 what size / type of diode I need

to jump my DPDT light switch so that;

- my front mast light comes on with my Stern when running

but so that;

- my stern does NOT come on with my front mast when anchored.

2 and where to purchase this diode.


I have a DPDT switch with 8 terminals (two of them Terminals 2 & 7 are for the switch lights though)

positions are

..........................left circuit ..........................right circuit


Position 1 ..............(Stern) 1 / .....2 -- ....3 \ (prt & stbd running lights)

Position 2 ..............(Bat +) 4 | ................5 | (Bat +)

Position 3 .......(front mast) 6 \ ....7 -- ....8 / (aft mast)


Position 1 = Running Lights - connects:
* stern (Terminal 1) to power (terminal 4)
* Front Mast (Terminal 6) via a jumper wire NEED DIODE HERE to Stern (terminal 1)
* Port & Stbd running lights (terminal 3) to power (terminal 5)

Position 2 = all off

Position 3: = Anchor Lights - connects:
* Front mast (terminal 6) to power (terminal 4)
* aft mast (terminal 8) to power (terminal 5)
* also connects stern light (terminal 1) jumped to front mast (terminal 6)

 

[alldodge]

This one does not need a diode and uses a Cole Hersee M-532 or similar

Most cases a diode is used with a SPDT switch and no mast head

 

[Outobie]

the top diagram is exactly what I have with my switch...stern light is on with both anchor and running lights...a diode is needed to keep the stern light off with anchor...or is the stern light supposed to be on with the anchor light? (that's how mine was wired from the factory) but I didn't think it was correct.


that bottom diagram references the diode series but now which one...

I just ordered a 1N4001 which has

• Body Diameter : 2.5mm
• Case Style : Axial D0-41
• Lead Length : 25mm
• Length : 5.2mm
• Operating Temperature Range : -55°C to +125°C
• Max Forward Current : 1A
• Forward Voltage : 1V
• Max Reverse Voltage : 50V,

no idea if the forward current, forward voltage and reverse voltage are correct or not...the other ones in that series were the same except they have higher reverse voltage ratings...I picked the one with the lowest...can't imagine I'd need more than 50 volts...but I don't know...thoughts?

 

[alldodge]

The big issue is the forward current and that's 1 amp for the diode selected. The regular incandescent 12V lamp can be more then 1 amp. If your using LED then its much less. Look at the bulbs watt rating. A 15W bulb pulls 1.25 amps.

Formula P=E x I
P=watts
E=volts
I=amps

I = P/E or 15/12 = 1.25 watts

So far as the mast head and stern light depends on the mast head light. When anchored at night your required to have 1 all around white light. This also depends on which kind and size boat you have

Mast head lights are for under power use

 

[Outobie]

boat is a 27' Tiara cabin cruiser. lighting is factory incandescent. no LED's. I'm calling it a mast head but its' the light mounted on a pole on top of the windshield. it has two bulbs one forward and one aft. it also has a separate stern light.

all of the diodes in that series have the same forward current rating of 1A

 

[alldodge]

OK, then its under 40 feet so you can have a stern and mast head light to make an all around light for anchor.

light mounted on a pole on top of the windshield. it has two bulbs one forward and one aft

OK with this you can turn off the stern light and turn on the rear white light for anchor.

If you use the diagram above with the Mast head forward/rear, you connect the lights in the pole with those connects. So when you turn off Nav lights the stern light goes out and the poles rear light comes ON, no diode needed

 

[Outobie]

ah you have it.! no diode needed....to translate to my switch...

Position 1 ……….....…...(front mast) 1 / .....2 -- ...3 \ (prt, stbd & Stern lights)

Position 2 .............................(Bat +) 4 | ................5 | (Bat +)

Position 3......( jumper to terminal 1) 6 \ ....7 -- ....8 / (aft mast)


Position 1 = Running Lights - connects:
* Front Mast (Terminal 1) to power (terminal 4)
* Port, Stbd & stern light (terminal 3) to power (terminal 5)

Position 2 = all off

Position 3: = Anchor Lights - connects:
* Front mast (terminal 1) via jumper to terminal 6 to power (terminal 4)
* aft mast (terminal 8) to power (terminal 5)

thanks for walking me through it!