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PostPosted: Tue Nov 01, 2011 5:42 pm
by vincen
Undertable wrote:for example and is the wiring OK as mentioned below?

Looks good :)

Vincèn

PostPosted: Tue Nov 01, 2011 8:51 pm
by fma38
I agree.

PostPosted: Wed Nov 02, 2011 12:18 am
by claudevh
The Voltage regulator "first level" (this one becomming hot ...) is capable of supporting 25 V but with some limit in intensity ... I don't remember ...
That this regulator become hot is normal !
Placing a small radiator can help !

Probably, this mixture of cables have conduct to a higher abnormal intensity ...
I don't really understand why you have removed the connectors from the PCB and why you have make direct soldering on the PCB. Those connectors contribute to the global cooling ... and you have placed the Bt module into a "closed" metalic box ... this isn't perfect for cooling !?!
Clearly the PCB (printed circuit board) has been "nearly burned" at some places ... :/
I don't see the small wire "antena" anymore, this can cause limitations in operational distance ...

Hey Oliver, you are a excellent "mecanic" but in domain of electronic .....:D

PostPosted: Wed Nov 02, 2011 7:14 am
by Undertable
Hello Claude
claudevh wrote:...Probably, this mixture of cables have conduct to a higher abnormal intensity

Doesn`t the current intensity depend on the electric consumer? In my case The BT-module is not connected in series to an other (bigger) consumer. Furthermore I measured the complete consumption of current which is similar to measured value of my other (also BT modified) Merlin: with BT 98-100mA, without BT 36,3mA. The difference is 63,7mA. Don`t know if this is normal for You`r module?

claudevh wrote:I don't really understand why you have removed the connectors from the PCB and why you have make direct soldering on the PCB

The connectors otherwise had to be insulated and clip off on the bottom side of the PCB, because I glued it with double faced adhesive tape on a plastics part, which is applied to the cover of my metal housing.

claudevh wrote:Those connectors contribute to the global cooling

hard to believe that cooling would be noticeable better with this connectors/pins.

claudevh wrote:you have placed the Bt module into a "closed" metalic box ... this isn't perfect for cooling !?!

My metallic box isn`t really closed. I milled a notch into the cover and placed a plastics part in it alone because of the radio transmission. As You can see on the photos, the plastics part is also milled and BT-module is placed in the milling groove, with antenna surface externally to the outside. BT module is glued on thin plastics part with double faced adhesive tape, in also the same manner as You do it in the original blue plastics box.

claudevh wrote:metalic box...isn't perfect for cooling

This is an interesting issue. I know nothing about the blue plastics material, perhaps it is optimized for cooling but I know that aluminium is a good heat cunductor, often used as material for cooling parts.
claudevh wrote:Clearly the PCB (printed circuit board) has been "nearly burned" at some places

I`m not proud on that but that`s my fault :/

claudevh wrote:I don't see the small wire "antena" anymore, this can cause limitations in operational distance ...

It`s in original condition. You can`t see it because it`s on the bottom side, which is glued on the plastic part

claudevh wrote:...but in domain of electronic .....:D

You`r right, I agree :) Thank god I don`t have to make money with electronic :)

PostPosted: Wed Nov 02, 2011 8:10 pm
by Undertable
I hope the ordered voltage regulator LM7808 will arrive tomorrow.
Today I found a 78L08 (TO-92) and tried it out.
Instead of BT`s voltage regulator "first level" the 78L08 is getting hot then and the BT`s voltage regulator stays cool.

Compliant with its datasheet recommended operating conditions are
Input voltage 10,5V - 23V (in my case 15,7V)
Output current 100mA max (in my case 66mA)
Operating virtual junction temp 70°C this is hot to the touch but seems to be a normal temperature :/

Oliver

PostPosted: Wed Nov 02, 2011 9:17 pm
by vincen
Undertable wrote:Operating virtual junction temp 70°C this is hot to the touch but seems to be a normal temperature :/

If you have enough room you can install a little piece of aluminium tighten screwed to the regulator, it'll help heat to go away ;)

Vincèn

PostPosted: Wed Nov 02, 2011 11:36 pm
by fma38
Be aware that 70°C is the *junction* maximum temperature. Due to internal thermal resistor, the body should not reach 70°C, or this mean that the junction temperature is higher than that.

PostPosted: Sat Nov 05, 2011 9:25 am
by Undertable
Yesterday the LM7808 arrived. BT`s hot voltage regulator stays cool and the LM7808 is getting warm to the touch first. After a few minutes it`s getting hot, too. Not as hot as the BT`s voltage regulator but hot to the touch, especially its GND-plate. Perhaps I should srew it on the matal-housing for cooling. TO-220 is applicable for this. The housing is GND, too so don`t need a mica plate for insulation

PostPosted: Sat Nov 05, 2011 9:46 am
by vincen
Undertable wrote:Perhaps I should srew it on the matal-housing for cooling. TO-220 is applicabe for this. The housing is GND, too so don`t need a mica plate for insulation

exactly what I advised you to do earlier in discussion :cool:

Vincèn

PostPosted: Sat Nov 05, 2011 10:28 am
by Undertable
So I did and it seems to be the perfect solution
Thank You Vincèn for proposal
...and thanks to all who were interested in my problem, too :)

PostPosted: Sat Nov 05, 2011 11:04 am
by vincen
Undertable wrote:Thank You Vincèn for proposal

you're welcome ;)

Undertable wrote:..and thanks to all who were interested in my problem, too :)

final result is really nice :) and looks very professional finish :)

Vincèn

PostPosted: Sat Nov 05, 2011 11:19 am
by Undertable
Thank You, I feel honoured :)

PostPosted: Mon Nov 07, 2011 7:46 am
by fma38
I agree, this is a really great hack!

Would you share the mechanical drawings?

PostPosted: Mon Nov 07, 2011 1:17 pm
by Undertable
Thank You,

to save time I didn`t design these parts with CAD. Because of this there are no drawings.
There are only a few incomplete freehand sketches on writing pad papers for some of the parts or rather of some areas of some parts.
edit: found one more sketch today

Feel free to have a closer look but please be aware that it is incomplete and barely skilled.
I don`t guarantee for correctness. Similarities to other (maybe protected) works are pure coincidence.
Please appreciate that I can`t give any missing measures because it will be very time-consuming.

Below You can see both footprints in comparison
Conditioned by the gearwheel I think it is not possible to reduce it a lot more.
Many thanks to Josef Graessle, who made a personalized TC-Control software version for my head.

edit: There is an album on my flickr account now which contains more pictures. Please press "L" to view specific ones on black or browse them here on black

Oliver

PostPosted: Wed Aug 21, 2013 5:43 pm
by Undertable
Hello again,

after trying out my Merlin-mod for a while I did some further small changes* and finished now.

*
- covered bullseye levels rearside (sun shined through at edge areas and caused malfunction)
- moved the RRS-rail 10mm. Scale starts with zero in the upper pivot axis now and rail is effectively 10mm longer.
- althogh I didn´t use it so far I insulated wireless trigger`s flash socket and connected it again (caused some trouble with bluetooth connection because of the conductive housing)
- additional LED for "wireless trigger ON"

So this is the final version:

PostPosted: Fri Aug 23, 2013 12:51 pm
by mediavets
Undertable wrote:Hello again,

after trying out my Merlin-mod for a while I did some further small changes* and finished now.

*
- covered bullseye levels rearside (sun shined through at edge areas and caused malfunction)
- moved the RRS-rail 10mm. Scale starts with zero in the upper pivot axis now and rail is effectively 10mm longer.
- althogh I didn´t use it so far I insulated wireless trigger`s flash socket and connected it again (caused some trouble with bluetooth connection because of the conductive housing)
- additional LED for "wireless trigger ON"

So this is the final version:

"small changes"? Is anything left of the orginal Merlin.

The end result looks wonderful - does it wrok well too?

PostPosted: Sat Aug 24, 2013 12:01 am
by Undertable
mediavets wrote:"small changes"? Is anything left of the orginal Merlin

I meant changes since my last posting in this thread. Altogether I modified a lot of course but still Merlin-Parts are the base, gear wheels, bearings, control and electrical drives.

Unfortunately I have no electronic skills so I was dependent on an [h]affordable[/h] complete solution which I wanted to modify.
mediavets wrote:does it wrok well too?

I`m pleased with it.