KL6 Driver in MRV with MC-E

[nein166]

So I decided to revisit the old MRV and change out the XR-E with a Nuetral MC-E.
I used a 650MCPCB from the Sandwich Shoppe to mount the MC-E on since 20mm stars don’t fit.
I put 2 pieces of Kapton tape down over contact pads to keep 4 of the legs from making contact.
I also lifted those legs slightly so the MC-E sits flat. Then I heated it to solder it in place.

I happened to have a KL6 driver in the parts bin.
The MC-E is wired up to 2s2p just like the old LuxV was internally.
But the MC-E will not see 700ma per die. From what I’ve read its around 300ma per die
I’m willing to risk the driver and bump up the current to see if the driver can handle more current.
I’ll be running it off 3*RCR123 or 4 CR123 and a spacer so its got head room in the buck to keep current draw lower.
I’d like some help identifying the sense resistor I should change to raise the current to about 1A to 1.4A

Is it A or B - Any suggestions as to values?

Pictures of the L.E.D. mounting and beamshots will follow after this gets sorted out.
And I’ll need to bore the smooth reflector to get the donut hole under control.

 

[TorchBoy]

Resistor A seems to be connected between two pins on the controller, which isn't how a sense resistor is normally connected. Resistor B appears to be connected between LED negative (the black wire) and ground, which is how sense resistors are often connected.

So I guess B. And it makes sense that if you halve the value of that resistor the output current will double... if the driver can actually take it.

Surely there are very inexpensive drivers that you could use instead. Why risk killing this one?

 

[Justin Case]

What are the markings on the ICs, esp the 8-pin IC and the 6-pin IC? Is the 6-pin marked "ACM"?

 

[nein166]

Resistor A seems to be connected between two pins on the controller, which isn't how a sense resistor is normally connected. Resistor B appears to be connected between LED negative (the black wire) and ground, which is how sense resistors are often connected.

So I guess B. And it makes sense that if you halve the value of that resistor the output current will double... if the driver can actually take it.

Yes B does look normal, I will try a R270 or the like in its place and see how the driver fares

Surely there are very inexpensive drivers that you could use instead. Why risk killing this one?

Well because it has sat for a while in a draw and it fits inside well.
And SF drivers don't have all the annoying strobe and SOS modes

 

[nein166]

What are the markings on the ICs, esp the 8-pin IC and the 6-pin IC? Is the 6-pin marked "ACM"?

Well its all in the light at the moment but I'll check that when I open it back up later to change the sense resistor.

 

[nein166]

Well I've salvage 2 R510 smd resistors and plan to put them in parallel in place of the R330.
I'm thinking this will get me to 0.26 Ohms of resistance. Not double but enough to see if the driver can handle the increase in output current.
I'm off to open the light back up.

 

[nein166]

What are the markings on the ICs, esp the 8-pin IC and the 6-pin IC? Is the 6-pin marked "ACM"?

8 pin: IOR (International Rectifier)
407M
2E2U
F7314
Maybe datasheet here

6PIN:?
LT1M

 

[nein166]

So I've changed out the sense resistor and it is brighter than before but I forgot to take a current draw reading at the tailcap before. But its brighter.
I don't have a clamp amp meter :sigh: no idea what the actual drive to the LED is. But its brighter so I'm happy.

Removed the resistor with a butane lighter, I need a heat gun so I stop singeing boards

2 R510 piggybacked for 0.26 ohm
SF coats the boards with a high heat resistant plastic coat,
Scrape it off of contacts or scratch your head wondering why your iron is not working

Kapton tape to isolate the pads connected to jumper wire

Positive contact spring, I got rid of the 2 stage system
and the battery tube bulkhead

 

[TorchBoy]

Removed the resistor with a butane lighter, I need a heat gun so I stop singeing boards

That sounds like a particularly bad idea to me because of the risk of lead poisoning.

 

[SirJMD]

"Removed the resistor with a butane lighter" - You did.. what?

It looks dreadful.. I could probably have made it better using a hammer. No offence, but go buy a d*mn soldering iron. Its $10 ...

 

[nein166]

That sounds like a particularly bad idea to me because of the risk of lead poisoning.

You should try it some time works great, less filling

 

[nein166]

"Removed the resistor with a butane lighter" - You did.. what?

It looks dreadful.. I could probably have made it better using a hammer. No offence, but go buy a d*mn soldering iron. Its $10 ...

Spent $70 on one and it works great just cant put the tip in 2 places at once like on both sides of a resistor thats why I say I need a heat gun.

 

[Justin Case]

The 3-terminal SOT23 IC is an LM431. The buck IC is an LT1772. The Linear datasheet discusses how the Vfb pin affects load current on P. 5.

 

[TorchBoy]

You should try it some time works great, less filling

But I don't want to try poisoning you, even if it fills you less full than other methods. :shakehead