[PSUBS-MAILIST] LED Lights

[David Colombo via Personal_Submersibles]

Hi Alan, one thing that I have observed so far is that without a heat sink,
the led will heat up in about 15 seconds and then start to flash on and
off.

On Mon, Jul 27, 2015, 12:29 PM Alan James via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> Hi David,
> you can get really simple with these LEDs & run the emitter straight from
> the power source. The light intensity fluctuates with the heat, but with
> the
> light intensity we are talking about, it might not be noticable. The trick
> would
> be picking a voltage low enough so that it didn't get too bright & burn
> out the
> emitter when it warmed up.
> Next step up in simplicity is to just stick a resistor in series, & there
> are
> calculators for this on line. I am wondering if a thermister instead of a
> resister
> would be a good idea, as this would restrict the current as the unit
> heated up.
> It may be a good option for running out of water if the thermister values
> were right.
> The beauty of this system would be that you would only have 2 components
> that you could damage by heating. The down side is a reduction in
> efficiency
> over a buck driver type system.
> Cheers Alan
>
>   ------------------------------
>  *From:* Seaquestor via Personal_Submersibles <
> personal_submersibles at psubs.org>
>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Tuesday, July 28, 2015 3:10 AM
>
> *Subject:* Re: [PSUBS-MAILIST] LED Lights
>
> Hi Cliff, maybe Phil could chime in on his led he demonstrated at his shop
> for use on the deep workers. It had only a flexible membrane over the oil
> compensated led housing. I think his design is about as compact as you can
> get, and I recall it had now fins, but run a voltage up to around 200+
> volts. Seems to me that simpler the better, is the idea here. For me I will
> testing my design hopefully next week. with 4 leds, wired for high and low.
> Based upon alum cost, machining, leds and  subconscious connector I'm
> coming in around $500 for each light. Cost may drop with multiple units.
> But one off is always more expensive.
>
> Best Regards,
> David Colombo
>
>
>
> Sent from my Verizon Wireless 4G LTE smartphone
>
>
> -------- Original message --------
> From: Cliff Redus via Personal_Submersibles <
> personal_submersibles at psubs.org>
> Date: 2015/07/26 1:28 PM (GMT-08:00)
> To: Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] LED Lights
>
>
>
> For anyone that has a large LED or halogens on their boat, can you share
> your experience on narrow beam vs flood lights.   Building a LED housing to
> be low profile to fit in a FRP recess is going to be difficult with a
> reflector to get a narrow beam.  As an example, a typical reflector size
> for a Vero 29 is 110mm (4.33") diameter and 67mm (2.64") deep.  This is
> massive and you still need housing and heat sink fins.
>
> I am wonder if we really need a focused light or is a flood light adequate?
>
> Cliff
>
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