Presale: The Ben Boost

[Blord]

Thanks for the pictures. They are looking good. Which side needs to be heatsinked when running at the max ?

 

[rhd]

pictures added! check first post for the pictures.

You will notice the two empty pads. This is where the set resistors go, and will be added when I fill the orders.

Total side-note (because I saw the Mohgasm PCB in that photo):

- How much run time can you get from a TO-252 based 1.8A Mohgasm WITH and WITHOUT heatsinking the top of the IC?

 

[tsteele93]

Question,

What would be your most common current settings? I can see around 500mA for several builds like 405 12x and 826 reds, maybe ~200-300 for osram single mode blues.

I guess a couple of ~800's to parallel for 1.8 (why not just use a mohgasm at 1.8?)

Anything else obvious?

In my noobophyte ignorance im just not seeing what all of these currents would be used for...

 

[Blord]

- How much run time can you get from a TO-252 based 1.8A Mohgasm WITH and WITHOUT heatsinking the top of the IC?

I wouldn't run any of the lineair driver without heatsinking them. The 1.8A Mohgash will run to melting point in few seconds. These drivers are hot.

The biggest advantage of the Ben boost will be the single battery configuration. You can build much smaller lasers with these drivers.

 

[rhd]

Question,

What would be your most common current settings? I can see around 500mA for several builds like 405 12x and 826 reds, maybe ~200-300 for osram single mode blues.

I guess a couple of ~800's to parallel for 1.8 (why not just use a mohgasm at 1.8?)

Anything else obvious?

In my noobophyte ignorance im just not seeing what all of these currents would be used for...

I can't see using these for 826 reds. What would you need to boost? Doesn't make sense to me.

But ~500mA for 12xs are good. 800s to parallel for ~1.6 or 1.7, etc. You'd use this instead of a mohgasm because perhaps you have a host well suited for a 26650, and there's no obvious 2x cell alternate to use that form factor.

I also like ~1.1 or 1.2A for (heatsinked driver) 445 builds.

And it's nice to have a 200mA on hand for single mode blues, and one day, greens.

I wouldn't run any of the lineair driver without heatsinking them. The 1.8A Mohgash will run to melting point in few seconds. These drivers are hot.

Ok, but what about heatsinked. I really want to know how (or IF) people are getting 1.8A sustained from a TO-252 package driver for more than ~45 seconds. When just heatsinking the TOP of the TO-252 IC, I haven't seen any decent run times AT ALL. What's the secret?

 

[Mohrenberg]

I know 1.6 and 1.8 will only last about 10-15 seconds before the thermal protection kicks I'm if its not heatsink.

 

[Mohrenberg]

Question,

What would be your most common current settings? I can see around 500mA for several builds like 405 12x and 826 reds, maybe ~200-300 for osram single mode blues.

I guess a couple of ~800's to parallel for 1.8 (why not just use a mohgasm at 1.8?)

Anything else obvious?

In my noobophyte ignorance im just not seeing what all of these currents would be used for...

I just listed all the possible combinations based on the 6 or 7 resistors I bought

 

[Mohrenberg]

I'll try one out tonight. The round ones seem to work pretty good with the top heatsink and them pressed against the pill, plus the solder mound on the positive input sits right underneath it.
It transfers heat well as I can feel the host heating up when I test the kits.

Now this driver, I ran that first one at 850mA and it got warm, but it never got hot. I held it the whole time for about 2 minutes.

 

[Mohrenberg]

I'll try one out tonight. The round ones seem to work pretty good with the top heatsink and them pressed against the pill, plus the solder mound on the positive input sits right underneath it.
It transfers heat well as I can feel the host heating up when I test the kits.

Now this driver, I ran that first one at 850mA and it got warm, but it never got hot. I held it the whole time for about 2 minutes.

 

[tsteele93]

I can't see using these for 826 reds. What would you need to boost? Doesn't make sense to me.

But ~500mA for 12xs are good. 800s to parallel for ~1.6 or 1.7, etc. You'd use this instead of a mohgasm because perhaps you have a host well suited for a 26650, and there's no obvious 2x cell alternate to use that form factor.

I also like ~1.1 or 1.2A for (heatsinked driver) 445 builds.

Yeah, I guess on the reds I was just thinking how cheap these are, didn't really think about them not needing the boost.

Why do 1.1A blue builds? Honest question, I just don't see why not go as close to 1.8 as you dare? Or say at least ~1.5A for longer life and still some serious power?

And it's nice to have a 200mA on hand for single mode blues, and one day, greens.

I like how you think!

 

[yobresal]

So that you can have LONG duty cycles without having to worry about the diode and driver getting too hot.

 

[benmwv]

Yeah, I guess on the reds I was just thinking how cheap these are, didn't really think about them not needing the boost.

Why do 1.1A blue builds? Honest question, I just don't see why not go as close to 1.8 as you dare? Or say at least ~1.5A for longer life and still some serious power?



I like how you think!

You dont have to run a laser to the max on every one you make. It isn't ALL about power

Plus many hosts just don't have enough heatsinking for 1.8A, and can't fit the batteries required to supply it.

 

[rhd]

I'll try one out tonight. The round ones seem to work pretty good with the top heatsink and them pressed against the pill, plus the solder mound on the positive input sits right underneath it.
It transfers heat well as I can feel the host heating up when I test the kits.

I would actually REALLY like to know if there's anyway to get a TO-252 based 1085 linear to hang in (even heatsinked) at 1.8A for more than 45 seconds or 1 minute. When the TO-252 is on a driver PCB, you can't directly heatsink the metal tab of the IC to the host. Without that ability, I haven't found any way to get such a driver to live past the 1 minute mark.

Why do 1.1A blue builds? Honest question, I just don't see why not go as close to 1.8 as you dare? Or say at least ~1.5A for longer life and still some serious power?

Hosts and batteries. If you're building a tiny host with a single CR2 or 10440 cell, there's no wisdom in shooting for 1.8. You won't be able to draw nearly enough current to boost up to 1.8A of output. Probably not even enough to boost up to 1.1A.

 

[tsteele93]

You dont have to run a laser to the max on every one you make. It isn't ALL about power

I agree, but I was thinking 1.5A was a nice safe, lower powered number!

Plus many hosts just don't have enough heatsinking for 1.8A, and can't fit the batteries required to supply it.

Very good point. I've been searching for copper sinks and larger hosts and I am stuck in that mindset right now.

EDIT: P.S. Moh, you have an order.

 

[Kizdawg]

These look truely awesome. Cant wait to start playing!

Did I hear you right saying you can parallel drivers of different amps?

 

[rhd]

These look truely awesome. Cant wait to start playing!

Did I hear you right saying you can parallel drivers of different amps?

Yes and no.

Yes, you can parallel drivers set to different output currents.

No, you will not actually end up with drivers delivering different output currents.

When you parallel two of these drivers, you're effectively putting their set resistors in parallel with each other. Lets say you've got two, with 0.22 and 0.35 ohm set resistors, creating currents of:

0.22 -> 863mA
0.35 -> 542mA

Two drivers, two currents set. When you parallel them, those resistors end up in parallel with each other, creating a total resistance of 0.135088 ohms.

Based on 0.19 / 0.135088, your total output current will be 1406 mA. This figure still represents the total of both currents added together, but the amount each driver contributes to that current will probably be closer to 1406 / 2 = 703mA.

Even though I didn't in my Saik build, I'd probably consider using 0.05 ohm balancing resistors on the output of each driver.