[PSUBS-MAILIST] PWM

Sat Apr 1 15:24:29 EDT 2017

Hi Alan,

I have plenty of time before i need lights so no hurry. I just kinda wanted
to get a complete LED system down so I would know what size to start
fabricating my housings. I still would like to go with LED as they last
longer and are brighter than the incandescent bulbs but I have no concept
of drivers or step up or PWM's so it is a bit frustrating. The guy in
California that I mentioned was an electrical engineer and knows this stuff
inside and out so I'll see if I can pick his brain a bit more and see if he
has any interest in making lights for us Psubs guys

Rick.

On Fri, Mar 31, 2017 at 5:38 PM, Alan via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> Rick,
> how soon do you need to get your lights done?
> I bought a few step up / step down constant current drivers that can
> handle
> a 100W LED. But no pwm dimming on them.
> Looking at them, you can do as Alec suggested & de-solder the trim pots &
> replace with wire to a potentiometer. You could use a certain sized
> resister in
> line to stop you dialling in more current than you need.
> I could play around with one & let you know how it goes if you like.
>    I am using 80W LEDs & get plenty of light from them driving them at 70W.
> My LEDs are the latest flip chip technology, that keep cooler out front.
> They are smaller than other comparable Watt LEDs enabling a smaller housing
> & thinner lens for the same depth.
> Alan
>
>
>
> My lights are having pwm dimming put on an led step driver tailored to my
> voltage. They said it was not that simple to add pwm dimming control.
> There is the
>
>
> Sent from my iPad
>
> On 1/04/2017, at 3:25 PM, Alec Smyth via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> Hi Rick,
>
> Yes, you need to match them and the assortment of drivers is quite
> bewildering. I knew nothing of this myself just a couple of weeks ago, so
> I'll try and summarize my selection logic but if anyone more knowledgeable
> finds me in error, please do jump in. I haven't even received my drivers
> yet, so my choice is untested.
>
> Generally these drivers are either "step up" or "step down" devices,
> meaning that they take the battery bank voltage and adjust it upward or
> downward depending on the voltage required for your specific LED. Not all
> LEDs of the same output have the same voltage requirement, so I can't
> provide a standard voltage for 10K lights and you will need to look that up
> on your LED specs. In most cases it should be clear which of those two
> varieties of drive you need, so deciding whether you need a step up or a
> step down driver I would say is the first cut at narrowing your choices. In
> my case I had an odd situation, because the battery bank voltage was very
> close to the LED voltage, and since the battery voltage will drop under
> load and with discharge, I could find myself crossing the threshold from
> stepping down to stepping up. There are a very few drivers that can step in
> either direction as needed, but I did find a few.
>
> To summarize then... Once narrowed down to step-up or step-down type, the
> next thing is to look at is voltage ranges. Each driver will have an input
> voltage range, which needs to cover your possible battery voltages, and it
> will have an output range, which needs to cover the LED spec voltage. This
> latter voltage is constant.
>
> Then finally, there's a choice of driver current capacity. This is a
> measure of how much power the driver can handle without burning out. Your
> LED will tell you how many amps it consumes. A sub in the tropics is a hot
> and humid environment with minimal ventilation, so I'm inclined to pick a
> driver that is way over-rated to prevent it from heating up much. Bear in
> mind you can also drive multiple lights off one driver if their combined
> current is within the driver's current capacity.
>
> As for dimming capacity, most drivers seem to have two pots, one for
> output voltage and the other for output current. These controls should
> allow you to dim the lights, but from what I saw they are typically small
> components on the board, and not something intended for manipulation by the
> end user on the fly. It may be you could replace a miniature trim pot with
> one on a cable, mounted on the face of your enclosure, but you would also
> need to be careful with the adjustment range. You would not want a knob
> that burns out your lights if you turn it a little too far.
>
> Hope that helps, but realistically you might find it'll take a day or two
> of research to narrow things down.
>
>
> Best,
>
> Alec
>
> On Thu, Mar 30, 2017 at 1:49 PM, Rick Patton via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>> Thanks Jim and Alec,
>>
>> Do i have to be concerned about matching the PWM to the specific LED
>> array I buy as there are so many out there. If so, can someone help me do
>> the match up as I have NO electrical back ground. I do want to be able to
>> dim the lights from 10,000 lumans down as much as I want as there will be
>> times where I won't need that much and it will also be a power savings on
>> my 36 V battery bank for my thrusters.
>>
>> Rick
>>
>> On Thu, Mar 30, 2017 at 1:37 AM, Alec Smyth via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>> Hi Rick,
>>>
>>> LEDs need a driver board to supply them with constant voltage and
>>> current, and Cliff's design includes an on-board PCB, inside the light
>>> itself, that does just that. The heat is dissipated by the housing, which
>>> is aluminum and has cooling grooves. Personally I opted for a larger off
>>> the shelf driver that will go inside the sub, because I didn't have much
>>> ability to solder the surface mount components and didn't have the need to
>>> miniaturize that was one of Cliff's design priorities. There are lots of
>>> drivers available, and I got mine on eBay like so many other components of
>>> the sub. This driver has a heat sink, but I don't expect it to heat up much
>>> at all. See eBay item 302203712954.
>>>
>>> Best,
>>>
>>> Alec
>>>
>>>
>>>
>>> On Thu, Mar 30, 2017 at 7:24 AM, via Personal_Submersibles <
>>> personal_submersibles at psubs.org> wrote:
>>>
>>>> Rick,
>>>> He was referring to a Pulse Width Modulator to adjust the amount of
>>>> power going to the lights.
>>>> Jim
>>>>
>>>> In a message dated 3/29/2017 11:29:44 P.M. Central Daylight Time,
>>>> personal_submersibles at psubs.org writes:
>>>>
>>>> Alec,
>>>>
>>>> I just met a guy in California that made his own underwater housing and
>>>> LED lighting system for doing video and he is using an LED board that is
>>>> about 3" square. He has built a PWM for it so he can dim it down and says
>>>> it's a 10,000 luman 100 watt system that runs on 32 volts.
>>>>  I don't know what a PWM is but he said that I didn't necessarily have
>>>> to have one. I can step my thruster motor supply down from 36V but one of
>>>> my concerns is how to get rid of the heat. He didn't seem to be too
>>>> forthcoming with the system he built. I think the LED array was something
>>>> like $15 each on Amazon. How are you controlling the heat in your housings
>>>> and do you think I would need a PWM for my lite?
>>>>
>>>> Rick
>>>>
>>>>
>>>>
>>>> On Wed, Mar 29, 2017 at 3:34 PM, Alec Smyth via Personal_Submersibles <
>>>> personal_submersibles at psubs.org> wrote:
>>>>
>>>>> My lights are done, I put them on Shackleton earlier today and they
>>>>> are wired through the hull with penetrators. However, the wires end inside
>>>>> the hull because I'm waiting for the drives to arrive, which will be
>>>>> installed inside the sub. I was able to test them with a lab type power
>>>>> supply on a table top, and must say these Bridgelux leds are like a little
>>>>> sun in a can, I love them. These two lights I made are 5K lumens, and I
>>>>> already have 10K lumen Bridgeluxes which I bought by mistake. So I'll test
>>>>> these, and probably make another set with those more powerful ones. If I
>>>>> do, the 10Ks will be the forward lights and the 5Ks will be oriented out to
>>>>> the sides for "peripheral vision". A dimmable driver is sounding like a
>>>>> good idea, or maybe just sunglasses!
>>>>>
>>>>>
>>>>> Best,
>>>>>
>>>>> Alec
>>>>>
>>>>> On Wed, Mar 29, 2017 at 9:10 PM, Alan via Personal_Submersibles <
>>>>> personal_submersibles at psubs.org> wrote:
>>>>>
>>>>>> Thanks Hank,
>>>>>> Alec has been making good progress with Cliff's light.
>>>>>> Last I heard 2 housings were being anodised.
>>>>>> Any update Cliff / Alec ?
>>>>>> Alan
>>>>>>
>>>>>>
>>>>>> Sent from my iPad
>>>>>>
>>>>>> On 30/03/2017, at 1:30 PM, hank pronk via Personal_Submersibles <
>>>>>> personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>> You will be our go to guy for lighting!
>>>>>>
>>>>>>
>>>>>> On Wednesday, March 29, 2017 6:15 PM, Alan via Personal_Submersibles <
>>>>>> personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>>
>>>>>> Still building lights Hank,
>>>>>> have built a couple of housings but are doing a third revision &
>>>>>> hopefully this one will be perfect. I am pretty happy with how it's
>>>>>> going.
>>>>>> Am getting a different LED driver made up with PWM dimming.
>>>>>> Got off the motor project temporarily as my brother wanted one of
>>>>>> the lights for his boat. 😐
>>>>>> Alan
>>>>>>
>>>>>> Sent from my iPad
>>>>>>
>>>>>> On 30/03/2017, at 12:35 PM, hank pronk via Personal_Submersibles <
>>>>>> personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>> Alan,
>>>>>> Are you back to work on your motor?   or are you still building
>>>>>> lights?
>>>>>> Hank
>>>>>>
>>>>>>
>>>>>> On Wednesday, March 29, 2017 4:44 PM, hank pronk via
>>>>>> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>>
>>>>>> Thanks' Greg
>>>>>>
>>>>>> Alan, my answer is who cares if some water gets between the seals.
>>>>>> The important part is to keep the oil inside the motor.  When the motor
>>>>>> starts up at the surface, there is significant centrical force that pushes
>>>>>> the oil out with the seal in its original orientation.  I should actually
>>>>>> remove one of the seals and just have one seal holding oil in, just like a
>>>>>> submersible well pump has.  Those pumps are VERY reliable.  Now having said
>>>>>> all this, I could be wrong ;-)   Stay tuned for test results.
>>>>>> Hank
>>>>>>
>>>>>>
>>>>>> On Wednesday, March 29, 2017 4:31 PM, Alan via Personal_Submersibles <
>>>>>> personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>>
>>>>>> How are you doing that Hank?
>>>>>> Are you compensating the gap between the two seals?
>>>>>> Otherwise you are in the same situation as the Minn kota motors
>>>>>> where one of the two seals will fail when you go beyond it's depth
>>>>>> rating.
>>>>>> Cheers Alan
>>>>>>
>>>>>> Sent from my iPad
>>>>>>
>>>>>> On 30/03/2017, at 10:40 AM, hank pronk via Personal_Submersibles <
>>>>>> personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>> Greg,
>>>>>> Good points, but I personally am not ready to give up on oil
>>>>>> filling.  I have reversed one of the two seals in my new motors for
>>>>>> Elementary.  One seal keeps the oil in and one seal keeps the water out.  I
>>>>>> am confident this in addition to the compensation system will make for a
>>>>>> clean leak proof set up.  The ice is off the lake by my house, so my test
>>>>>> lake should be open in a week or so.  I will know then if my idea works.
>>>>>> Hank
>>>>>>
>>>>>>
>>>>>> On Wednesday, March 29, 2017 7:03 AM, james cottrell via
>>>>>> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>>>>>
>>>>>>
>>>>>> I have to say, I no longer think that WD40 is the best for
>>>>>> compensating things underwater. Over time it causes plastics and rubber to
>>>>>> harden and become brittle.
>>>>>> Silicone oil is better but the other problem with oil compensation in
>>>>>> general is that the smallest drop/leak makes a very visible oil slick
>>>>>> around your sub (not good). Most guys are using trolling motors and they're
>>>>>> not really tight enough to hold thin oil without leaks.
>>>>>> Back in the 90s I was using air compensation- and it actually worked
>>>>>> really well. As far as I know, Karl Stanley has also been using air
>>>>>> compensation for a long time without problems.
>>>>>> It's a clean system that's not hard to set up and a small bottle of
>>>>>> air lasts for many dives.
>>>>>>
>>>>>> Greg C
>>>>>>
>>>>>>
>>>>>> ------------------------------
>>>>>> *From:* "MerlinSub at t-online.de via Personal_Submersibles" <
>>>>>> personal_submersibles at psubs.org>
>>>>>> *To:* Personal Submersibles General Discussion <
>>>>>> personal_submersibles at psubs.org>
>>>>>> *Sent:* Tuesday, March 28, 2017 12:55 PM
>>>>>> *Subject:* Re: [PSUBS-MAILIST] WD - 40
>>>>>>
>>>>>> On a brushless motor it will maybe work with mineral oil.
>>>>>> On motors with brushes I have bad expierence with that.
>>>>>> Mineral oil is a big problem in a lake if a motor is even a little
>>>>>> untight.
>>>>>>
>>>>>>
>>>>>>
>>>>>> -----Original-Nachricht-----
>>>>>> Betreff: Re: [PSUBS-MAILIST] WD - 40
>>>>>> Datum: 2017-03-28T17:15:59+0200
>>>>>> Von: "Brian Cox via Personal_Submersibles" <
>>>>>> personal_submersibles at psubs.org>
>>>>>> An: "Personal Submersibles General Discussion" <
>>>>>> personal_submersibles at psubs.org>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Hi Carsten,
>>>>>>                         I did a small test trying to light the WD40
>>>>>> on fire.  It's not as flammable as I thought it would be.  I think they
>>>>>> have improved it's non-flammability with new formulation. It's still
>>>>>> somewhat flammable however.
>>>>>> I will be using a light mineral oil in my motors.
>>>>>>
>>>>>> Brian
>>>>>>
>>>>>>
>>>>>>
>>>>>> --- personal_submersibles at psubs.org wrote:
>>>>>>
>>>>>> From: "MerlinSub at t-online.de via Personal_Submersibles" <
>>>>>> personal_submersibles at psubs.org>
>>>>>> To: Personal Submersibles General Discussion <
>>>>>> personal_submersibles at psubs.org>
>>>>>> Subject: Re: [PSUBS-MAILIST] WD - 40
>>>>>> Date: Tue, 28 Mar 2017 07:22:02 +0200 (MEST)
>>>>>>
>>>>>> Heat Vapor is may a problem with WD40.
>>>>>> May ensure that the compensating back is big to handle that..
>>>>>> We change to silicon oil for that reason.
>>>>>>
>>>>>> vbr Carsten
>>>>>>
>>>>>>
>>>>>>
>>>>>> -----Original-Nachricht-----
>>>>>> Betreff: [PSUBS-MAILIST] WD - 40
>>>>>> Datum: 2017-03-28T04:56:46+0200
>>>>>> Von: "Brian Cox via Personal_Submersibles" <
>>>>>> personal_submersibles at psubs.org>
>>>>>> An: "PSubs" <personal_submersibles at psubs.org>
>>>>>>
>>>>>>
>>>>>>
>>>>>> I just ran one of my motors filled with the WD40.  It seemed to be
>>>>>> very happy.  I mainly just did it to clean the carbon build up out of the
>>>>>> motor.  I was surprised how sealed the motor was, it is open at one end
>>>>>> where it mates to the gear box.  I was able to fill it up without it
>>>>>> leaking out anywhere.  That could be an issue later when I want the mineral
>>>>>> oil to fill all the voids.  I might need to actually drill some holes to
>>>>>> get some circulation .
>>>>>>
>>>>>>
>>>>>> Brian
>>>>>> _______________________________________________
>>>>>> Personal_Submersibles mailing list Personal_Submersibles at psubs.org
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>>>>>>
>>>>>
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