Variable Output Mag-D thanks to JM-SST Special Edition

Hi

JimmyM has just started providing his JM-SST (PWM Soft-Starter with Variable Trim) to the masses ! First two batches Sold Out - More to come . . .

When he started designing these I asked if he could make me a Special Edition version with the facility to add an external Pot for Variable-Output.

My JM-SST (SE) arrived just before Christmas and the 1meg pots arrived Christmas Eve and now I have just managed to get some time to fit it all together - this is how it worked out.

First of all pull out the D-Switch and disassemble



Cut a groove through the middle of the blue bit to fit the 12mm Type 51 Pot (RS #393829 )





Cut down the middle and one of the flat guides of the black bit enough to accomodate the pot



Fit the pot into the Mag-Switch





Cut a channel in the outer case to accomodate the larger pot dimensions





Drill the necessary holes and attach some bits of electric string.

I decided to run a constant live (red) to the normal switch pos and use a tail switch for on/off.

I also mounted the JM-SST(SE) rotated 180 degrees to standard to prevent any conflicts with rear traces and the wires and pins.



Cut a groovey channel for the Earth-Neg Feed and loop into position



Solder on the Neg-PWM wire and feed the Pos Supply wire through



Solder onto the Pos Spring (added magnet for better contact) and assemble fully.




The central post of the pot removes and allows access to the grub screw for fitting. Hopefully I will work out a proper knob for the pot but in the meantime the std. 25mm post works just fine for testing.

Camera batteries flat but switch now assembled into my 5E Mag-D IRC65 (5xE-Moli) and set for full power on the trim giving 40-100% Duty Cycle on the Pot.

It's GREAT.

:twothumbs

BIG Thanks to JimmyM for making these.

Cheers Pete

Nice article you posted. Good job. I still need to hook up my JM-SST. I really wanted an external pot. I wonder if one could be added?

Regards,
Mark

Nevermind. I read more closely about the tailswitch.

Sweet work. That pot is perfect. It has a hole in the middle to get at the grub screw! Dude, awesome. Where did you get that POT?

JetskiMark said:

Nice article you posted. Good job. I still need to hook up my JM-SST. I really wanted an external pot. I wonder if one could be added?

Regards,
Mark

Click to expand...

Hi Mark

I think the 1Meg pot goes where the wiper resistor is
normally fitted to the trim pot ? I don't know if any other components are changed but JimmyM will no doubt let us know the real details. Shouldn't be too difficult apart from the tiny soldering and the little drill holes !

I think Jimmy is working on bigger better things with external pots for your really big mega lamps.

Cheers
Pete

The "special" version has a modified PCB to allow the connection of an external pot in addition to the trim pot on the board. This allows you to set a absolute maximum duty cycle and not exceed that regardless of the position of the external pot.
Of course there's nothing to stop you from removing the pot from an existing "standard" and wiring in an external one.
Actually, I'm going to change the PCB so that if you decide to make this change, it will be easier.

This is great. Thanks, Pete. wow. Quite a scary amount of Dremeling you did there. :green: Amazing switches. They've got their electrical limitations but I think you've just pushed the limit of what can be done with the body. oo: :laughing:

You found a pot with a hole through the middle! :duh2:

I hope I don't need to do this - "need".
I take it the tail switch is what you're doing next?

Meanwhile, I'm getting what components I can, and hoping I can solve the problem of getting a bored 3D to avoid using a 4D or 5D. ...Or 6D, more like it. How do you get 5 Emolis into a 5D? 5 x the extra 8.5mm...that's about 42mm - is the standard spring that long?
I must've spent a lot of the...all night/last night/this morning going between the custom pack thread, the bulb testing thread Excel images, the boring and honing threads...:sigh: I suppose I can get everything except the M*G-Lite and the batteries, and then see what happens.

You've hacked that switch so much already,...I wonder if it wouldn't be possible to fit a rocker on the other side of the body, opposite the pot shaft, instead of going to a tail switch. ...But I suppose the tail switch would be easier.

PS: :laughing: This is definitely the "Thread of The Day." :laughing:

Or a pot with a switch built into it. Full left turn to "click" shut off.

cat said:

This is great. Thanks, Pete. wow. Quite a scary amount of Dremeling you did there. :green: Amazing switches. They've got their electrical limitations but I think you've just pushed the limit of what can be done with the body. oo: :laughing:

You found a pot with a hole through the middle! :duh2:

I hope I don't need to do this - "need".
I take it the tail switch is what you're doing next?

Meanwhile, I'm getting what components I can, and hoping I can solve the problem of getting a bored 3D to avoid using a 4D or 5D. ...Or 6D, more like it. How do you get 5 Emolis into a 5D? 5 x the extra 8.5mm...that's about 42mm - is the standard spring that long?
I must've spent a lot of the...all night/last night/this morning going between the custom pack thread, the bulb testing thread Excel images, the boring and honing threads...:sigh: I suppose I can get everything except the M*G-Lite and the batteries, and then see what happens.

You've hacked that switch so much already,...I wonder if it wouldn't be possible to fit a rocker on the other side of the body, opposite the pot shaft, instead of going to a tail switch. ...But I suppose the tail switch would be easier.

PS: :laughing: This is definitely the "Thread of The Day." :laughing:

Click to expand...

Thanks Cat

12mm Type 51 Modular Carbon 200mW top adjust linear 1MOhm from RS #393829 (RS-AUS Link)

(but their site is down for updating so I can't get the link yet) £3.45 for 5

- Just lucky they're a perfect fit !

Tail Switch from cmacclel.

My 5E Mag is either a 6D or a 4D plus long and short FM Tubes

JimmyM said:

Or a pot with a switch built into it. Full left turn to "click" shut off.

Click to expand...

Thanks Jimmy - Great idea if you can find one to fit - still searching.

Cheers Pete

Wow Pete,

couple of your pics didn't come out. Hope it is just on my end. That is some tutorial.

jimjones3630 said:

Wow Pete,

couple of your pics didn't come out. Hope it is just on my end. That is some tutorial.

Click to expand...

Hi

Just tried refresh and seems OK ?

ImageShack can be a bit temperamental so hope it sorts itself out.

PM me if you want me to e-mail any shots that you just can't get - if you want to.

Cheers Pete

JimmyM said:

Or a pot with a switch built into it. Full left turn to "click" shut off.

Click to expand...

Of course!
But...with the hole through the middle and the dimensions (and electrical specs?)...might be a bit much to hope for. :laughing: ...and I see Pete's put the part number in there now.

cat said:

Of course!
But...with the hole through the middle and the dimensions (and electrical specs?)...might be a bit much to hope for. :laughing: ...and I see Pete's put the part number in there now.

Click to expand...

The only thing you need is to be betwen 750K and 1M. Power is nearly zero. It's like uA.

petrev said:

12mm Type 51 Modular Carbon 200mW top adjust linear 1MOhm from RS

(but their site is down for updating so I can't get the link yet) £3.45 for 5

- Just lucky they're a perfect fit !

Click to expand...

Too good if you found the same thing with on/off.

I didn't know you had RS in England - assuming you don't mean RS Components. (I think I might just search there now.)

petrev said:

My 5E Mag is either a 6D or a 4D plus long and short FM Tubes.

Click to expand...

The Emolis are C diameter, so could one fit into the D tail cap? (On a 5D. The spring length must be pretty close to that extra battery length anyway.)

cat said:

Too good if you found the same thing with on/off.

I didn't know you had RS in England - assuming you don't mean RS Components. (I think I might just search there now.)

The Emolis are C diameter, so could one fit into the D tail cap? (On a 5D. The spring length must be pretty close to that extra battery length anyway.)

Click to expand...

I think RS is short for Radio Spares ? Started in 1937 in London selling spare parts for radios. http://rswww.com but RS Components is one of their names.

Just found the Australian website is working and the link is THIS for the Pot #393829

RS Worldwide Portal

Think 5D is too short even using the tail space but I don't have one to try ! 5xD is 300mm and 5E is 350mm

Good thinking though as it could mean using less of an extension on a 4 or 5 to get the right length ! ! !

Cheers Pete

damn. rs-southafrica.com is redirecting to that offline notification page.

I see now from that picture why it's got a hole in the middle.

Back to the incan testing page and the battery pack page to see what I can do with a 4D.
...5D...the length of a 6D compared to a 5D, hardly matters. :green: None of them are really practical anyway.

cat said:

damn. rs-southafrica.com is redirecting to that offline notification page.

I see now from that picture why it's got a hole in the middle.

Back to the incan testing page and the battery pack page to see what I can do with a 4D.
...5D...the length of a 6D compared to a 5D, hardly matters. :green: None of them are really practical anyway.

Click to expand...

Have Fun

RS back up again 2-Jan !

In the first photo: Is that lock nut / heavy duty switch grub screw the standard one? (I need to re-read the Kiu D instructions, I think - I'm only familiar with the C's so far.)

cat said:

In the first photo: Is that lock nut / heavy duty switch grub screw the standard one? (I need to re-read the Kiu D instructions, I think - I'm only familiar with the C's so far.)

Click to expand...

Yes - Just the standard grub screw/nut. Looks different as I try to remember to always screw it into the nut fully, so that I don't lose while working ! Lost one before as they tend to be right at the limit of the thread when you remove them from the Mag. The grub screw falls out and passes to an alternate quantum universe . . .

Pete

Fantastic job, Petrev. That switch dremel work is about what I did to get the Judco 12A switch that Mac uses in tail to fit in default side Mag switch. Covered with rubber boot, you can't tell its there. I'm trying to decide if I want the adjustable trim like you setup.