beratung/ advice on parts

  • entschuldigung. meine deutsch ist slecht. aber Sie können im deutsch antworten.


    I am trying to upgrade a (dive) light from halogen to LED.
    In first I just replaced the 2 halogen (20+35w) bulbs for 2 (2,5w) LED bulbs but the output of light was not satisfactory. The burn time was way beyond expectation.
    Talking to various persons about this the outcome was that this kind of modification does not work well. We even talked about just modify just the bulb but with the new high power LED the heat must be taken care of.
    To make it work I designed a heatsink that fits in the housing and will be sealed by x-rings (the way it was originally designed).
    So now I need to find someone to fabricate this for me.


    However, I still have some questions (I am handy but I don’t have the expertise of choosing/combining the right electrical parts).
    I am thinking of putting 2x 10w HP leds (high Lumen), which I can (thermo)glue to the heatsink.
    Enclose the proper driver or drivers (if needed also (thermo)glued to the heatsink on the other side of the LED. The height can be max. 22 mm
    The grayhill rotary switch has 4 connections (OFF, LIGHT 1, LIGHT 1+2, LIGHT 2) but if possible (depending choice of driver) I want to change this in: OFF, LIGHT 1/50%, LIGHT 1+2/50%, LIGHT 1+2/100%.
    The battery pack has 13.2 v 4500mah. (11 cells).
    If Can you help me with which parts to choose? And a wiring diagram, costs.


    I can send the drawing of the heatsink so you can have an idea of what the plan is.
    Thank you very much. Paul

  • Hey Paul! I think the success of your endeavour will greatly depend on how well you/your heatsink will be able to get the heat to the surrounding water. That means firstly you need a thermally conductive lamp host and secondly a good thermal connection from heat sink to host. If either of the two is not provided I'm afraid your LEDs will die a quick death. The heat sink may be great but as long as it is unable to unload it's heat to the surroundings it's just a life extender for a couple of minutes. So maybe you ought to give some more detail on your host, the heat sink an its thermal connection to the host in order for anyone to assess your options.
    best,J

  • Hi L4M4, Juisoo,


    Thanks for the answers.
    I already put a request on that form and will see what will come out of that.


    I already understood that the LED and driver need to be heatsinked (if this word exists). Therefor the heatsink is design to have contact with the water (or air).
    Trying to add a pdf file with (auto cad) drawing but I don't see how to do that here. But i keep trying.


    The old case holds 2 halogen bulbs 20-35 w which produced also a lot of heat. What I want to do is add a aluminium plate covering the old sealings and place the cover the same way as it was originally designed to cover the lights.
    A pic will explain all.. but...
    so housing...seal.... aluminium 15mm (20 if counted all) with some fins.... cover.


    As i told before: I miss the expertise but seeing/studying a lot of designs i think this may do it job.


    Paul

  • If Can you help me with which parts to choose? And a wiring diagram, costs.


    Ok, to get this straight. You need recommendations on
    1) the LEDs
    2) the driver
    3) how to connect it all to get your preferred switch settings


    is that correct, does the list lack anything?


    As for 1) I'd recommend the Cree XM-L2 in combination with a step down converter like https://pcb-components.de/led-…2800ma-5v-28v-detail.html. Number 3) is the most challenging I guess and I don't have a good Idea atm.

  • Thanks,


    I saw the driver can be connect to a dimmer...... The battery pack has a dimmer. can this be used????


    Edit
    About the settings: It is just a wish
    if it is just on or off.... ok
    but i like to turn on each light individually or both. this will leave me to choose spot or flood it i can find the reflectors.


    Reading about the dimmer will not work as the less will be turn on off and this will show on photo or video.

  • ok
    I did some reading and beside i got more confused I also learned something.


    To run a led in a good way you need a driver (a Buck or boost buck).
    And a good heatsink of course.


    As i don't want to change to much on the housing, I think i can make a heatsink and extent the heatsink connecting the LED and driver there.


    Basics:
    Battery pack is 11 cells 13,2V 4500mah, I can modify this but that means I need a new charger
    Battery pack has no room for buck or other electrical components (with 11 cells)
    case, with the designed heatsink I have room for 2 drivers max diameter 30mm by height 20 mm
    the case has a grayhill rotary switch and "no" i don't want to change that. I want to use this for turning on/off and when possible for high low beam/ 1 or 2 lights. There are 4 stands original: OFF / LIGHT 1 / Light 1+2 / Light 2
    LEDS: as there is 13.2V powering 2x XM-L2 is no problem. i even think i can power 2 x MT-G2 which have a good CRI rating!


    I am lost on what to choose, is possible and what combines yes or know.


    What is a good combination and give the best results?
    There are so may buck drivers. I don't know which to choose


    Some come with 5 modes (low strobe mid high etc) and i tried to understand how it works but i can not find how to switch between the levels..... Yes a button but how is it connected?
    Will I loose a lot of power/Run time from the battery using the xm-l2?


    Thanks for the help
    Paul

  • 2x XM-L2 is no problem. i even think i can power 2 x MT-G2 which have a good CRI rating!


    Actually the CRI doesn't depend on the Chip or LED-Housing but on the so-called Phosphor. You'll find a High-CRI VErsion of the XM-L2 as well:
    http://www.mouser.de/Optoelect…d=LED+Cree+XMLBWT&FS=True


    I would not recommend a multichip-LED such as the MT-G or XHP50 (which I would prefer of the two) for the reason that your power-pack outputs 13,2V and two 6V MT-G or XHP in a row would already amount up to 12V. Most buckdrivers need more than 1V voltage overhead to function properly and if your battery pack drops a little in voltage over time, you might cut it a little too close.
    Therefore I recommended a LED that has a Vf of ~3V. If you're after decent color rendering you simply have to look for the high-CRI bins of the desired package.


    If you prefer a 6V LED then you might want to consider a Lowdrop linear CC driver (such as e.g. the instructables-KSQ). That might work well.
    EDIT: Uh, no. If you switch to single LED than you would have to burn all the excess voltage, so forget that.

  • In my opinion its a good idea to use those MT-G2 Emitters.
    They are small enough to do that spot and flood thing and they are powerful (up to 20 watts). You could use the 6V or maybe also 9V Chip depending on the lowest voltage at low battery (must be higher that the LED Voltage, as already mentioned).
    For the driver you may use any 3 amp buck/step-down driver which is also suitable for XM-L LEDs. One driver for every LED. This allows you to switch on and off both lamps independently.

  • Thanks for the information. I am getting the hang of it.


    As you all suggested the case is this.
    I need to get the LED voltage as close to the total voltage input. In my case 13.2V.
    I have 2 battery packs and 2x 2 light cases so we are flexible.


    So let me get it straight...

    • the choice of running just one LED 3V in a case with a battery pack 13.2V means I have to burn about 9V to heat. That looks no good! :/
    • running 2 LEDS 3V (total 6V) i have to burn about 6V to heat.
    • I can run 2 LEDS on one driver right? do I loose potential or whatever?
    • Running 2 lightcases 2x 3V LEDS (total12V) on a pack 13.2V. I am going to running it short? ?( ......this option would be great for me! :rolleyes:
    • see 3 but with dimmer; see parts list
    • can I combine LEDS XM-L2 and a MT-G2? Don't think it is wise but?!?!?


    I said i don't want to change much on the housing but I could put in a "drehpoti" in the place of the grayhill switch and a PWM board. Will this help me? point 4


    parts of choice so far: (I can only find some driver 3A till 12.6 V and they don't serve)
    https://pcb-components.de/led-…2800ma-5v-28v-detail.html
    https://pcb-components.de/led-dimmer-module/nano-dim-v2-mini-pwm-dimmer-3-5v-30v-12-53-detail.html
    https://pcb-components.de/zube…0k-ohm-detail.htm</a><br>
    with the dimmers it will be a bit more costly but at least i can control the light they way I want.


    If you would be so kind to give your opinion, I will thank you with all my 1.83m :whistling:


    paul

  • I need to get the LED voltage as close to the total voltage input. In my case 13.2V.
    I have 2 battery packs and 2x 2 light cases so we are flexible.


    So let me get it straight...

    • the choice of running just one LED 3V in a case with a battery pack 13.2V means I have to burn about 9V to heat. That looks no good! :/
    • running 2 LEDS 3V (total 6V) i have to burn about 6V to heat.
    • I can run 2 LEDS on one driver right? do I loose potential or whatever?
    • Running 2 lightcases 2x 3V LEDS (total12V) on a pack 13.2V. I am going to running it short? ?( ......this option would be great for me! :rolleyes:


    You got that wrong :)
    You can use a buck-driver and then you dont have to burn the voltage, it regulates it (but there has to be at least 1V, most of the time it needs about 1.2V between Vf_LED and V_battery).
    If you want to use a simple linear-constant current driver (with PWM for example) you need to get as close to the batteryvoltage as possible, cause linear-drivers burn the voltage (buck converters/drivers dont)
    You can run as many LEDs as you like, as long as both voltage and current are below what the battery can provide

  • In my opinion its a good idea to use those MT-G2 Emitters.
    They are small enough to do that spot and flood thing and they are powerful (up to 20 watts). You could use the 6V or maybe also 9V Chip depending on the lowest voltage at low battery (must be higher that the LED Voltage, as already mentioned).
    For the driver you may use any 3 amp buck/step-down driver which is also suitable for XM-L LEDs. One driver for every LED. This allows you to switch on and off both lamps independently.


    If you use 2 Drivers you may of course use 6V LEDs. However I would still run the thing with 1 driver where the switch will decide where in the circuit it feeds the voltage, such that you have either one or both LEDs in a row. With two in a row and the necessary overhead voltage the 6V version is cutting it too close.

  • Juisoo, you didn't pay attention to the fact, that you must not put a switch on secondary side of the LED driver, because it will break either those LEDs or driver :!:


    Paul does want to use the original mechanical switch of his light, so in my opinion we have to use one driver for each LED to comply with his requirements (LED1/LED2/different brightness).


    Furthermore we will get some kind of redundancy with two different drivers. As all of us know every electronic circuitry may fail sometimes.

  • Another possibility (if you dont wanna use two drivers or dont have the space for them) is to use the switch to change the sense-resistor of the driver and thus dim the output - no switching on one or two LEDs, but always use two and just set them at different brightness

  • Who Stop halt ...... getting ?(


    First I want to thank you for answering in English but I can read and understand German. Just writing and speaking will make my mind go crazy. Speaking 3 languages daily already let me mix up words... 1 extra will .... :wacko: me.


    "FaKrae" made me happy with his answer not burning voltage so I was thinking like "Juisoo"...... see attachment (electrical).... but as "Derschwert" says this is not possible...... ????? it seemed logical.


    2 drivers (1x 1500 and 1x 3000 with different LEDs crossed my mind (but i am trying to reduce the costs if possible)... and yes there is space enough to put in. Here i can choose with the switch led1 / led 2 / or both... easy


    I have no problem if the 2 leds are lit all the time but it would be fine to reduce them then.
    "fakrae" How do you see this? I understood that the original switch could not select modes! even so I have difficulties finding 3A driver for the bat pack so i sticked to the PCM driver mentioned earlier. what kind of driver do you have in mind?


    Thanks guys ( for making it more complicated as it was ;) )


    Paul

  • I dont see it on this one, but others that are like it switch modes with the push of a button. Push once: mode1, push another time: mode2... push n-th time: off, starting with mode1 again.


    Constant-current drivers use a sense resistor to measure the current and adjust the voltage. If you put in another resistor the output-current changes.
    You can now remove the resistor from the pcb, connect your knob to where it was and use it to switch between resistors, thus virtually putting them in as needed.



    Your scheme wont work, because if the desired current can't flow (your switch is in the wrong position) voltage goes up as far as the battery can go, then you switch on a LED, it gets a lot of power and dies before the driver can weaken the voltage. Same goes from switching between one led and the other (there is a time in between where none is on)

  • ok understand,


    so the option is this:
    1 driver and removing a resistor from the board, solder wires an where the resistor was, buy another one and put the resistors connected to the switch so i can switch from low to high resistor.
    question: do i have the nerve to do it?
    question: can i select the switch in not selecting any resistor or must there be one always selected? ooo wait i can put in 3 or 4 as there are 4 switch positions.


    To do this I need gooooooood advise and courage


    thanks paul