diodes for lighting

[ghostlymoron]

I want to arrange my compass light to be on when either the motoring lights or the sailing lights are on. I believe this can be done without a separate switch using diodes to prevent backfeeding. What sort of diodes do I need, where can I buy them, how should I wire them?

 

[Rigger Mortice]

Something like an IN4001 will do it. Get them from Maplin or Ebay (cheaper, but they are only a few pence) Wire them in the positive line on both circuits with the band facing the compass light.

 

[ghostlymoron]

To make it even clearer, do you think you could draw me a diagram?

 

[Rigger Mortice]

Sorry but I'm using an ipad and I have no idea how to do that. Sorry.

 

[nigelmercier]

To make it even clearer, do you think you could draw me a diagram?

Will a diagram really help? The diodes RM suggested look like this:

Connect both ends with the silver bands to the compass light, and the other ends to the two switch outputs. If that still doesn't make sense, call in an electrician.

 

[cimo]

a "schematic"? haven't used mspaint in ages.

The bars on the diode symbols correspond to the silver band on the actual component.

 

[ghostlymoron]

So i can connect them at the panel. That's good. I don't think i need an electrician.

 

[GHA]

What a good idea :thumb:

Think I'll do the same, free up a circuit breaker.

Cheers.

 

[GHA]

Sorry but I'm using an ipad and I have no idea how to do that. Sorry.

Fred Rift but you can share the same scribbles here....

https://awwapp.com

https://awwapp.com/draw.html#1e8bb6f5

 

[ghostlymoron]

If i connect the diodes to the switch, i then need some kind of terminal block to connect compass wires to. Obviously not choc blocks, but what?

 

[cimo]

So i can connect them at the panel. That's good. I don't think i need an electrician.

neat and tidy behind the switch panel.
Insulate the diode leads well, of course.

(i'd use choc blocks)

 

[VicS]

Choc blocks but make sure they are all brass. Not brass with steel screws.

 

[nigelmercier]

If i connect the diodes to the switch, i then need some kind of terminal block to connect compass wires to. Obviously not choc blocks, but what?

Obviously not choc blocks, as you say (sorry Vic, I hate them).

If you already have FastOn crimp terminals, then get some piggy-back terminals (with a combined plug and socket) to double up the connections on the two switches...

Solder the diodes to short lengths of wire, and encase in heat-shrink, then just crimp both wires to the diode common ends together in another FastOn. If you want one made up, say what wire length and size and gender terminal you want on the common end and I'll send you one for an RNLI donation.

 

[ghostlymoron]

I've got soldered connections on my 3 way switch panel (very basic electrics)

 

[nigelmercier]

I've got soldered connections on my 3 way switch panel (very basic electrics)

In that case it is simple, just solder the two extra wires to the switches, and use a crimped connection for the diodes to the disconnected compass wire. You could solder it, but it will need heat-shrink to protect it.

 

[ghostlymoron]

If i were to use choc blocks should i use crimped on ends. I don't like just putting the stranded ends under a screw.

Choc blocks but make sure they are all brass. Not brass with steel screws.

 

[AntarcticPilot]

Just a thought, but an LED is, of course, a diode! So, would using an LED (with the correct polarity) work instead of using discrete diodes?

 

[alahol2]

Just a thought, but an LED is, of course, a diode! So, would using an LED (with the correct polarity) work instead of using discrete diodes?

No, because you would have to connect both (potential) positives to the same leg of the LED. Switch one on and you make the other live. I'm sure you realised that 5mins after posting, which is what I usually do.

 

[AntarcticPilot]

No, because you would have to connect both (potential) positives to the same leg of the LED. Switch one on and you make the other live. I'm sure you realised that 5mins after posting, which is what I usually do.

Duh!

 

[Rigger Mortice]

I've got soldered connections on my 3 way switch panel (very basic electrics)

Do you have a tricolour or "conventional" nav lights?