Noob question on scanners.

[TechJunkie]

Thanks Mop, but I think 20s maybe a little to slow for what I want. But I guess if the price is right we can talk.

[TechJunkie]

No recommendation on some Chinese analog drivers? Or do I have to go FlexMod?

[swamidog]

chinese drivers aren't typically analog.

No recommendation on some Chinese analog drivers? Or do I have to go FlexMod?

[The_Doctor]

No recommendation on some Chinese analog drivers? Or do I have to go FlexMod?

Are you good with soldering through-hole boards, and can make a prototype printed circuit board? Or know someone who is? If so, there's a fast analog mod design in Sam's Laser FAQ. I know this because I put it there. People might think 1MHz is way too fast to be sensible, but it makes a LOT of difference on the kinds of flashing dots Swamidog and Galvonaut like to use, or anythign where a strong bright line must start clean and fast. Things in other drivers may be better these days, I don't know, but I've seen graph plots of earlier versions of at least two designs, that showed a stooped-shoulder response even as low as 100 KHz. A really fast driver means you get very clean and accurate response, and timing. The snag with mine is that so far there is no ready-built one for sale. (And it's probably not as compact as some people want, but on the other hand it can drive 5 amps...).

[Galvonaut]

....... there's a fast analog mod design in Sam's Laser FAQ. I know this because I put it there. People might think 1MHz is way too fast to be sensible, but it makes a LOT of difference on the kinds of flashing dots Swamidog and Galvonaut like to use, or anythign where a strong bright line must start clean and fast. Things in other drivers may be better these days, I don't know, but I've seen graph plots of earlier versions of at least two designs, that showed a stooped-shoulder response even as low as 100 KHz. A really fast driver means you get very clean and accurate response, and timing. The snag with mine is that so far there is no ready-built one for sale. (And it's probably not as compact as some people want, but on the other hand it can drive 5 amps...).

This is very interesting. I was considering getting flexmods, but maybe these would be a better option. Are the boards available unpopulated or is this a ground up build?

Keith

[TechJunkie]

chinese drivers aren't typically analog.

Yeah I've noticed that, thats why I asked. I hate being frugal, its not my style, but the more stuff costs, the longer my project takes to finish. I may have to go TTL.

Are you good with soldering through-hole boards, and can make a prototype printed circuit board? Or know someone who is? If so, there's a fast analog mod design in Sam's Laser FAQ. I know this because I put it there. People might think 1MHz is way too fast to be sensible, but it makes a LOT of difference on the kinds of flashing dots Swamidog and Galvonaut like to use, or anythign where a strong bright line must start clean and fast. Things in other drivers may be better these days, I don't know, but I've seen graph plots of earlier versions of at least two designs, that showed a stooped-shoulder response even as low as 100 KHz. A really fast driver means you get very clean and accurate response, and timing. The snag with mine is that so far there is no ready-built one for sale. (And it's probably not as compact as some people want, but on the other hand it can drive 5 amps...).

I do know someone that can do that. The only trouble is he is super busy, and we'd have to order the PCBs in bulk. I dont know if there would be a high enough demand here to sell them off. Can it be done on a bread board? Also will it work with all the RGB diodes?

Can you send me a schematic?

[swamidog]

a system is only a fast as its slowest laser. if you have any dpss laser in the projector, it won't matter a single bit if you're driving the DI diodes at 1Mhz.

if you like the kinds of shows that galvonaut and i do, you won't be satisfied with TTL.

Yeah I've noticed that, thats why I asked. I hate being frugal, its not my style, but the more stuff costs, the longer my project takes to finish. I may have to go TTL.



I do know someone that can do that. The only trouble is he is super busy, and we'd have to order the PCBs in bulk. I dont know if there would be a high enough demand here to sell them off. Can it be done on a bread board? Also will it work with all the RGB diodes, or just with lower power diodes?

Can you send me a schematic?

[TechJunkie]

No DPSS, all diode.

If I can get these drivers made, maybe we can do a mini group buy to get them cheaper.

[The_Doctor]

No boards so far... Just the post on Sam's FAQ, and some Gerber files of a slight revision. I have some help on this, but it's still work in progress. We wanted a built board but the firm had dedicated software that won't open Gerbers. I think it may be better to get the boards made then sell as kits, with some prebuilt for extra charge, but right now I'm saving money for some laser cases and Buffo, who's been helping me, is busy a lot of the time, so don't hold your breaths.

Swamidog, true for DPSS, their response is lousy. But even there it still makes sense to get the fastest response you can on the other stuff. The reason is as simple as this: You can slow a fast response. You can't speed up a lousy slow one. A lot of people are using timing correction boards, at extra complexity and expense. It's better to get the driver right first time, then slow it in software to match the slowest part of the system. At least that way you get full control wherever possible. Anything else just leaves even more mismatched problems to solve. Another way to look at it is: Suppose an analog driver is to take a square wave at 10 KHz. Doesn't sound like a lot, but how good a square do you want? If you want it clean and sharp you need multi-hundred KHz bandwidth just to do that even if the period is only 10KHz.

EDIT:
Breadboarding won't work. One thing about clean fast edges with no overshoot is precision control of RF performance at least up into SW frequencies. Which means good PCB design. Otherwise the performance might be degraded too much. It's not as demanding as scanner electronics, but it still needs care. Empirical testing of a built board is needed to be sure it's right, which is why I put a full PCB layout in the FAQ with the rest of it.

[TechJunkie]

So you never even tested a completed design? Sorry, I thought you had a proven set up. You got me all excited for a minute, LOL.

Can you point me in the direction of your post? I can run it by my friend. He has connections with a Chinese PCB maker. Maybe he can make up a prototype for testing.