YAPPy lights?

prv

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As I was making my way home from the cricket yesterday in the falling light, I pressed the lightbulb button to illuminate my Seatalk instruments - of course they all lit up with the press of one button, but equally obviously the non-seatalk instruments in the cockpit (compass, engine RPM, etc) didn't. And this gave me an idea - a small board which would listen to the Seatalk bus and close a relay when a "lights on" command went past. Then you could wire all your "dumb" instruments' lighting supplies via the relay.

I thought this was quite clever, but then today I realised there was a further refinement possible. On Kindred Spirit (where all the instrument lights just used a simple 12v supply) I had them wired to the nav light circuit. I never even needed to think about illuminating the instruments; by the time it got too dark to read them, the nav lights had already been on for an hour and the dials were lit up ready. So in fact, the interface board wants to be the other way round - a terminal which senses 12v, emits a seatalk "lights on" command when it first sees it, and a "lights off" when the 12v goes away again.

Obviously it's a completely unnecessary refinement and I could just use a manual switch - but I think it would be quite swish, and isn't one of the Ps in YAPP supposed to stand for "pointless"? :)

Pete
 
On a slightly related subject. Airliners have a switch in the cockpit called "storm lights" This sets all instrument lights on to full brilliance with one switch. The theory being that lights should be very dim for best night vision but if there is lightning about you don't want to have your night vision completely blinded by a lightning flash. So you have full brightness in cockpit. Not really applicable to boats though. good luck olewill
 
. So in fact, the interface board wants to be the other way round - a terminal which senses 12v, emits a seatalk "lights on" command when it first sees it, and a "lights off" when the 12v goes away again.
The circuitry to do this is in my latest fuel gauge, but I haven't got round to finishing it yet. It's a winter project, from two winters ago :)
 
There is a case when under sail in not having the engine instrument lights on so I guess a refinement would be to have some control, a relay, that isolated engine panel lights when the ignition key was off.
 
There is a case when under sail in not having the engine instrument lights on

Yep - I believe my panel only lights up when you switch it on. It's all-electronic, so its behaviour is a little mysterious, but I believe the "light" wire is merely a control signal to inform it that the other panel lights are on, not a direct supply to a lightbulb as on an older analogue gauge.

Pete
 
Seatalk have 3 light settings would you want the compass light dimmed as well

I wouldn't, no. That's taking things too far :). Compass lights usually seem to have about the right level of illumination anyway.

In any case, the question doesn't make any sense in my preferred approach (second paragraph in my original post). That is, the non-seatalk lights are all wired up and switched traditionally, and it's the seatalk that follows their lead rather than vice versa. I assume that having sent a "lights on" command when the YAPP first detected 12v on the lighting circuit, you'd then be able to adjust light intensity on seatalk from the instruments in the normal way.

I guess a useful refinement in the area of dimming would be the ability to specify (via jumpers or DIP switches on the board) the level you want it to request at initial lights-on. Pressing the button on the instruments brings up level 3 by default, and that's too bright for me.

Pete
 
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