Is Your Boat Self-Sustaining Electrically?

[haiqu]

Those spiders sound nasty. The breaker should go in series with the Vcc (12v) line, so it switches the whole circuit out. Cheers,

Rob

[Jaxxiam]

One thing to think about is the mounting location of the light sensor. Bird crap, dust, spiders will need to be cleaned off every now and then.

[noelex 77]

Originally Posted by haiqu

A light dependent switch would fix that. As soon as dawn comes along the lights go off. They also turn on automatically at dusk. Good if you aren't aboard, or want to sleep in. :-)

Here's one that uses a 555 timer IC:



Rob

Rob have you any information of the self consumption of the circuit?

The 555IC has quite low consumption but with LED anchor lights it's easy for the consumption of a circuit like this to come significant especially if it's consuming power over 24hours.

Anyone looking for a commercial solution the Bebi owl LED anchor light is very bright has low power consumtion and can be ordered with a light sensor to turn it off/on. All for about $40 plus postage.

LED Anchor Light-Waterproof & Rugged for Marine RV and Offgrid Use

[haiqu]

Originally Posted by noelex 77

Rob have you any information of the self consumption of the circuit?

The 555 consumes about 100mW at 12v and overall consumption will be that plus the power usage of the original LED when it's on. In savings from forgetting to manually switch the thing off, you should be well ahead. IOW there's really no reason not to use this circuit unless soldering up a piece of Veroboard (tm) is beyond you.

The chip itself sells for under $0.50 (20 pcs for $7.99, free postage) on eBay. Light dependent resistors are around $0.35 in 10-off quantities.

Fitting it on a vertical surface should obviate the need for cleaning.

BTW the load can either go from the Output pin to Ground, or to +12V, depending on whether you need to switch something ON or OFF at night. The Output pin can source or sink 200mA, larger loads can be routed through an additional transistor switch or even a relay.

As far as basic electronic building blocks go, the 555 would have to be one of the most useful ICs ever invented. I'm sure you can think of a few other uses for a timer chip aboard as well. A 20-min wake-up buzzer while single-handing, a shower pump timer? Wouldn't leave the dock without 'em.

The 555 book has loads of additional uses listed: http://www.4shared.com/rar/iy3nZYxK/555_book.html

Rob

[noelex 77]

Originally Posted by haiqu

The 555 consumes about 100mW at 12v and overall consumption will be that plus the power usage of the original LED when it's on. In savings from forgetting to manually switch the thing off, you should be well ahead. IOW there's really no reason not to use this circuit unless soldering up a piece of Veroboard (tm) is beyond you.

The chip itself sells for under $0.50 (20 pcs for $7.99, free postage) on eBay. Light dependent resistors are around $0.35 in 10-off quantities.

Fitting it on a vertical surface should obviate the need for cleaning.

BTW the load can either go from the Output pin to Ground, or to +12V, depending on whether you need to switch something ON or OFF at night. Larger loads can be routed through an additional transistor switch, or even a relay.

Rob

So the circuit is consuming about 1/7 of the power of the anchor light (using the Bebi owl as a reference).

Another way of looking at it is you could leave the anchor light on without the automatic circuit for an extra 3.5 hours per day and be even with the power consumption of the LED light with the automatic circuit left to switch itself off and on.

[webejammin]

Originally Posted by noelex 77

So the circuit is consuming about 1/7 of the power of the anchor light (using the Bebi owl as a reference).

Another way of looking at it is you could leave the anchor light on without the automatic circuit for an extra 3.5 hours per day and be even with the power consumption of the LED light with the automatic circuit left to switch itself off and on.

Works for me It ain't broke

[haiqu]

Originally Posted by noelex 77

So the circuit is consuming about 1/7 of the power of the anchor light (using the Bebi owl as a reference).

Another way of looking at it is you could leave the anchor light on without the automatic circuit for an extra 3.5 hours per day and be even with the power consumption of the LED light with the automatic circuit left to switch itself off and on.

Checked their website but could only find the power consumption of the Owl without a light sensor. Since you didn't mention a current figure for that model I can't really comment further. I was impressed with the low power and their use of a PWM regulator. However at $39.25 + $23.65 shipping (to Australia) it's an expensive option.

Regardless, the 555 circuit is also able to turn on other things at the same time such as alarm systems, electric fences (don't laugh, after reading the thread on theft from boats I'm considering one!) and motion sensor lights. And I do like to make my own stuff, finding it far more satisfying than buying off-the-shelf.

Rob

[noelex 77]

If we used the 555 circuit with an LED anchor light the circuit consumtion is in the order of 1/7 of the anchor lights consumption. (The Owl was only used to illustrate the point. I have measured the consumption of this anchor light and can verify its 0.06A in my case)
I agree that building these things is very satisfying, but I think the circuit consumtion needs to considered carefully to determine if the added complexity and potential unreliability is justified.