Need suggestions for creating blanking from 5V ttl with non-ttl laser module

[michelrietveld]

laser blanking.jpgHello all, new to this forum so first let me introduce myself
Michel Rietveld age 39, been playing with lases since i got my first tube from a optical disc player which needed a cascade power supply.
Now i am currently working on an x-y r,g & b scanner.
Bought myself a PT-Itrust ILDA controller board from Phoenix Technology.
Have 2 x 30K mirror with driver attached and just for the fun a 200mW green laser pen.
I use I-Show software, interfaces through usb to my ilda interface.
Shows run smooth but as my laserpen does not support blanking i would like to create some sort of deflecting mirror to fade/blank the beam from the ttl blanking output of the board. Anyone done this before? I have a spare mirror and driver type G120DT which i would like to hook up to the 5V ttl output.
I have a picture on how to control the beam in combination with a 90 degrees mirror setup. See attachment.
Any suggestions or should i just invest in a laser module that has ttl steering build in?

Michel

[mixedgas]

Depending on the amplifier for your G120, TTL should be just fine for Galvo blanking. See there are a few kinds of TTL used in the laser world. The real TTL switches at 1.6 and 2.4 volts. Fake TTL is high speed CMOS logic and switches from about 100 mv to 4.90 volts.

If you have "fake" TTL you will need a potentiometer to reduce the signal to your blanking galvo amp, and then you will be ready to go.

If you have real TTL, you may need a simple "LEVEL SHIFTER" circuit to develop enough swing for your galvo, but again, there may be enough movement in 0.8 volts of change for your application. There most likely is enough change in .8V for galvo blanking.

Good Luck, Steve

IF, and it is not likely, but IF you need a level shifter, here is a simple one:

[michelrietveld]

Depending on the amplifier for your G120, TTL should be just fine for Galvo blanking.

So i just connect the 2 pin output of my controller card to the 4 ping galvano board, have to figure out which pins to connect.

See there are a few kinds of TTL used in the laser world. The real TTL switches at 1.6 and 2.4 volts. Fake TTL is high speed CMOS logic and switches from about 100 mv to 4.90 volts.

If you have "fake" TTL you will need a potentiometer to reduce the signal to your blanking galvo amp, and then you will be ready to go.

Just checked on my scope, seems to be fake ttl from 0 to aprox 5 v what kind of potentionmeter value do you suggest?

If you have real TTL, you may need a simple "LEVEL SHIFTER" circuit to develop enough swing for your galvo, but again, there may be enough movement in 0.8 volts of change for your application. There most likely is enough change in .8V for galvo blanking.

Good Luck, Steve

IF, and it is not likely, but IF you need a level shifter, here is a simple one:[/QUOTE]

[chad]

As for the pot, really anything will work. 5k , 10k.

chad

[hobbybob]

Hello all, new to this forum so first let me introduce myself
Michel Rietveld age 39, been playing with lases since i got my first tube from a optical disc player which needed a cascade power supply.
Michel

Hi Michel,

Your name suggests that it's very likely you are Dutch (or maybe Belgium) ?
Welcome on the PL forum, change your profile so people can see where you're from, that helps a lot in getting help from "local" people.

In November or December there will be a LEM in Ilpendam, organised by our (i still presume your Dutch) fellow countryman McCarrot. Joining us there, will get you lots of knowledge, you can share ideas and see what other people built/are using/designed etc.

Well... hope to hear more from you ?

Kind regards,
Dimitri

[mixedgas]

Agreed, 5K -10K would be just fine.

Steve

[drlava]

mirror blanking is cool in a nostalgic kind of way, but if you don't mind modding the laser pen you could replace its driver with one that accepts ttl control. I can think of one low-current one (good for pens) that I didn't make that costs about $6.

[michelrietveld]

Good tip, have been thinking about that also, i also have another diode at hand, salvaged from a very cheap laser show projector with stepper motors created figures (duh..) so i would like to give it a try with this one.

the drivers i on found, on ebay, that support ttl seem to be limited to 10K speed, will this be sufficient? and how will i be sure i don't overload the laser, for example, feed it too much current.

Michel

[michelrietveld]

I ordered the FlexMod P3 Laser Driver, why is no green lasorb protector availlable?
I will use this for the red and green diode i salvaged from a stepper motor driven el cheapo lasershow device

Michel

[hobbybob]

Hi Michel,

Until recently green was made from IR (808nm), nowadays you have also direct injected diodes, but most green is still made from IR diodes and crystals.
This IR beam is shot through 2 crystals ND:YVO or ND:KTP where one crystal makes the wavelength 1064nm and one doubles the frequency (so the wavelength is half that, being 532nm ie Green). (very simply said, i am not a physics professor)

So to protect your green you need a RED Lasorb (since the RED lasorb also protects IR diodes).