GDx3 "BigMac" Converter @ 3.3A

Here's something that threw together that I will be using for an upcoming mod. I think it's pretty obvious what I will be driving with it.

Each GD is set to 1111 to give me a total of 3333. I will be potting it with alumina oxide.

I would love to measure the actual current output but I'm afraid. I've already blew a GD previously by the emitter lead falling off accidently when powered up. Is there something I could add to open load protection so I can measure current with confidence? Like a zener diode is it or something?

What kind of drawbacks will I run into using this setup besides the high cost?

Thanks

Re: GDx3 Converter @ 3.3A

Dark...

I don't know the answer to any of your question, but the SandwichShoppe just came out with a GD3000 for $30.... J/K.:nana: We could only wish. Just wondering, are you doing 1 LiIon or 3 NiMh? Good luck!

Re: GDx3 Converter @ 3.3A

Supernam said:

Dark...

I don't know the answer to any of your question, but the SandwichShoppe just came out with a GD3000 for $30.... J/K.:nana: We could only wish. Just wondering, are you doing 1 LiIon or 3 NiMh? Good luck!

Click to expand...

Damn you! Almost had me! :laughing:

I bought GDs from the shoppe at different times & a couple on BST. So I had 7 GD boards on hand when I decided to do this. I'm going to run 1 Li-Ion.

Re: GDx3 Converter @ 3.3A

darkzero said:

Here's something that threw together that I will be using for an upcoming mod. I think it's pretty obvious what I will be driving with it.

Each GD is set to 1111 to give me a total of 3333. I will be potting it with alumina oxide.

I would love to measure the actual current output but I'm afraid. I've already blew a GD previously by the emitter lead falling off accidently when powered up. Is there something I could add to open load protection so I can measure current with confidence? Like a zener diode is it or something?

What kind of drawbacks will I run into using this setup besides the high cost?

Thanks

Click to expand...

If you can wait a day or two I can try this setup and verify the functionality.

I have a lot going on right now, but, I can try to squeeze this in.

Wayne

Re: GDx3 Converter @ 3.3A

dat2zip said:

If you can wait a day or two I can try this setup and verify the functionality.

I have a lot going on right now, but, I can try to squeeze this in.

Wayne

Click to expand...

Sure I can wait. Really appreciate it Wayne.

Data sheet for the IC states 1.2A output max. Not sure what other components that take in effect to the over drive but I figure 1111 each should be ok.

Re: GDx3 Converter @ 3.3A

Re: GDx3 Converter @ 3.3A

Ran some quick tests today.

P7 CSWOI emitter mounted on a LuxI star board & mounted on a finned 45mm x 45mm x 15mm heatsink

1x AW Protected C Li-Ion @ 4.1v

Peak Iin: 5.2a, after 2 min 4.0a continuous.

Iout: 3.35a continuous, vf: 3.2v

Only thing potted on the stack of GDs currently are the inductors but it wasn't for thermal reasons. After 1 min it got warm, after 3 mins if got uncomfortable to hold in the hand clinched tightly.

I feel confident using it & will go ahead with it. I'll be potting the GDs in alumina oxide & into a ecan but not directly to the bottom of the emitter heatsink. The host should be on it's way tomorrow. Should have it all done on the weekend for my birthday!

Re: GDx3 Converter @ 3.3A

Please post some Birthday Pics!!!:thumbsup:

Re: GDx3 Converter @ 3.3A

darkzero said:

Ran some quick tests today.

P7 CSWOI emitter mounted on a LuxI star board & mounted on a finned 45mm x 45mm x 15mm heatsink

1x AW Protected C Li-Ion @ 4.1v

Peak Iin: 5.2a, after 2 min 4.0a continuous.

Iout: 3.35a continuous, vf: 3.2v

Only thing potted on the stack of GDs currently are the inductors but it wasn't for thermal reasons. After 1 min it got warm, after 3 mins if got uncomfortable to hold in the hand clinched tightly.

I feel confident using it & will go ahead with it. I'll be potting the GDs in alumina oxide & into a ecan but not directly to the bottom of the emitter heatsink. The host should be on it's way tomorrow. Should have it all done on the weekend for my birthday!

Click to expand...

Awesome. Reminds me a McD Big Mac.

Wayne

Re: GDx3 Converter @ 3.3A

Now thats thinking outside the Burger Box!
Nice job

Re: GDx3 Converter @ 3.3A

dat2zip said:

Awesome. Reminds me a McD Big Mac.

Wayne

Click to expand...

I like that! That is what I will call it. Bigger burgers are better!

Re: GDx3 Converter @ 3.3A

I always just solder wires when testing the current on converters before potting. I don't trust a clip to not fall off the LED!

I hope that thing has some SERIOUS heatsinking. That's a 500ma over drive and seoul's phosphor is not known for doing well with heat (tint shift). I have a P4 mounted very well and it will shift if pushed much farther than 1amp. but at 1amp it's fine so I don't like to overdrive them.

Re: GDx3 Converter @ 3.3A

IsaacHayes said:

I always just solder wires when testing the current on converters before potting. I don't trust a clip to not fall off the LED!

I hope that thing has some SERIOUS heatsinking. That's a 500ma over drive and seoul's phosphor is not known for doing well with heat (tint shift). I have a P4 mounted very well and it will shift if pushed much farther than 1amp. but at 1amp it's fine so I don't like to overdrive them.

Click to expand...

I always solder my LED & converter connections. I don't have any extra set or DMM leads to solder wires to when testing for current. I've found a solution so I went ahead with testing.

My P4s will tint shift when overdriven in less than a minute. I ran the P7 I have for 5mins+ at 3.3A with no tint shift at all so I think I'm ok. The emitter was not even epoxied, only had Artic Silver 5 thermal grease during testing. I'm still testing different configurations though. I want to see how far I can push it.

Re: GDx3 Converter @ 3.3A

Supernam said:

Dark...

I don't know the answer to any of your question, but the SandwichShoppe just came out with a GD3000 for $30.... J/K.:nana: We could only wish. Just wondering, are you doing 1 LiIon or 3 NiMh? Good luck!

Click to expand...

Where can I find a GD3000?

You can't. Well I could make you one if you really want but it's not practical, way too expensive.