Handling Blanking or Modulation For maXYZmodules

[marconi]

Hi All

This post is for the request of circuits using different on hand parts
for assembling a circuit for driving the Opto blanking on the maXYZmodule.

As most of you that have bought a maXYZmodule RED have found out , we use inverted blanking.

This was done on purpose for the buyers that didnt need blanking , about 75percent. And to make it more universal.

But for those that do not have the ability to (invert) blanking in the software they are using ., I have came up with a few circuits to help you out.

The First is my favorite.. The 74hct14 Hex Schmitt Trigger Inverter , also a 74hct04 Hex Inverter may also work here..
come to think of it .. 7404, 7414 ... LS , HC,HCT, ALS or just about any in this family will work.
It is a sensitive circuit and works the best. It uses a 7805 5volt regulator for the chip and a few filter caps.. and a reverse polarity diode. a 1N4002.


First off we are driving a opto-isolator.. it is basically a LED and a photo transistor inside of a chip.
It needs about 10 to 15 ma of drive to saturate the photodiode..
The output from your computers parallel port will NOT drive these directly., But will drive this circuit.
Some Servo driver boards that have drivers for blanking or operating soleniods
have this driver - on board.... my board is a Lasermedia and has these .

So basically what we are doing is providing more current to drive the opto .
We are also paralleling two inverters in the chip. There are 6 inverters in the chip total. all are NOT used.
We could also add another inverter in front of the parallel pair "IF" we
do not want or need to invert..By inverting twice we end up non-inverted with more drive for the Opto-coupler.
By using pin 5 as the input and pin 6 would tie to pin 1 and 3 instead.
I realize now that I should have posted this a long time ago as this would have helped out so many.
(I was assuming most "knew" how to use basic logic chips)..
My Bad...

*^_^*

[marconi]

Here's another circuit ...

Altho simple but effective stand alone . it will work in a pinch



Or, You could clean-up the input by using this circuit

[marconi]

Here's one using an Op-Amp

NE532n

of course you could use the 74hct14 or 04 in front of this too!!!

Remember ... these circuits are only good for the maXYZmodules lasers only!
Using these on other lasers may cause unpredictable behaviour and may
damage your laser...So dont try this at home , kiddies

Should you need help with any of these , please feel free to contact me or the_kcar for help...

Also., If you want analog modulation ,
Just remember to take advantage of the voltage knee of the input of the Opto ., It shouldn't take much thought there I would hope..@!!!


*^_^*

[MechEng3]

Thanks for the diagram !!!! I will build today. One question is that I am assuming the two capacitors in the first circuit are 1uF and 22uF values. I have used the LM358P for blanking with good success in conjunction with a LM 317 and similar cap setup close to the 532n op-amp circuit.
I just did'nt have the knowledge to use the 74 series logics safely.....besides these are your designs. Not wanting to kill it, I did the best thing....ASK !!!!!!!! Thanks again and will post a good scanned image without trace lines in red soon. 8)

[marconi]

Hi MechEng3

Yes , By all means use whatever you have to get the job done is
my motto...

I dont see any problem using 358's , experimentation...
Just try not to exceed 30 or 40 ma on the drive to the Opto
altho it does have a 100 ohm resistor inside for current limiting
I dont think it'l go that far.. if it starts too, just add another 100 or so
in series is all..
Yes, 1uf and 22 uf. at 16 volt caps
altho not critical values, a little more wont hurt..
LM317's are kewl devices too..

Glad to be of help...
Post your circuit when your done..hehehe

Have Fun

*^_^*

[marconi]

Hi All.

Starting Nov 1 all maXYZmodules will arrive with Positive Blanking.
I have found a way to get it all inside the module.. Hooray
And the circuit only draws 1ma if that from the TTL driver.

NOW., It truly is TTL without any add-ons
(I know...Its about time) ..but that was it..I didnt have the time to do
more research as between the day job and this has kept me too busy
to dig deeper..and with the help of all of you here it is now complete.

You can still order them with reverse blanking if you wish...For Analog
or for the simpler control systems..

If you recieved your module already , It may still need the options
in the above post.

Thanks everyone for being patient..

[marconi]

Ok.. Ive had a few requests for driving these with a Analog signal

This is only for the Style 1 units or units made before NoV 1 2005
If you want this style please request it or you will get a TTL model.

Use this to drive it with 0 to +5 volts from your board

It will still be inverted tho... ie , 0 volts for full on ,.+5 for full off


If you want to do Audio or some other A/C signal do this

This circuit will have backwards modulation so as it sits will not forward modulate to 90 percent.. but it will give you an idea what to do.
its something I need to finish when I get more time.
Adding a transistor to the output to invert it... stay tuned


Use your imagination !!!

[marconi]

If you need a cheap reciever or detector for the voice data
try a small photocell from RadShack or a detector from an old VCR
or a CD laser photocell ,. even a red led will work.
add an audio amp
and/or add an op-amp between the photocell/dector
and amp for more gain.

mount the photocell in a tube (keep it dark inside)...
use shielded wire the the op-amp/audio amp
add a telescope lens (old binocs work).
and presto... Laser audio

I may draw up something for those that need more here...ask

Again, use your imagination!!!