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200mW of green for $125 shipped!!!!!!!!!!!!!

paulzimm

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LOL - I didn't even think of that! I have several PC power supplies sitting in my "bone yard" right now. I will test which of the leads are 5 volt. Thanks for the tip :)
 

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Hello, I just got my 150mW green Analog in the mail today and I am heading over to pick it up after work today. I want to test it out until my RGB rig is complete. Over the weekend I made a 5V (sorta) supply by using 4 x very low AA batteries in series with a 10K Ohm potentiometer. Will this work or do you think I may damage it from too much current?

Also, when I hook it up to a multimeter I see that it starts at about 4V with the pot turned down (max resistance) and peaks at about 5.4 volts with the pot turn up (least resistance). Is there a better circuit I could build that maybe would be a bit more linear?

My primary concern is that I do NOT want to damage the unit. Also, in post #151 (scroll up) the member describes that the TTL/Analog input wires are crossed and that the Black wire is really the positive and that the Red wire is the negative. Is this true with all of these or maybe just a fluke with his unit? Thanks in advance, will be sure to leave REP points :)
I don't think connecting it with reverse voltage damaged it in anyway. Mine's still working great. For the power supply, I used the 5V output from my arduino and created a simple voltage divider with a potentiometer and a resistor to give me a range from 2.0V to 5.0V. As other's have suggested try using a LM317 or other standard voltage regulator if you don't already have a 5V supply. When you get yours working, can you tell us whether the power output is linear compared to the voltage? (see my post above to see what mine does with a difference of only 0.04V)
 
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I see.
It is just that in my world equipment with external control signal will normally come with internal supply for than signal.

The idea of an external signal to a print using external supply sounds risky to me.
It's for laser show safety. Generally you do not want the lasers to come on until you specifically tell them to. The Chinese have yet to implement TTL that is normally off, I think because less people RMA because they think the laser is faulty, but with analog it must be normally off to be compatible with ILDA standard.

The external supply is not risky at all in most cases since the laser driver incorporates limiting to prevent the diode from being pushed too far by the incoming modulation signal, should it exceed 5V.
 

qumefox

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Yeah. What EF said. heh. The modulation input is just a reference voltage. It just sets power from 0% to 100%. Even if you put in more than 5v, your still limited to 100% because that's a laser power supply limitation. The laser RUNS off it's own power supply, it's just CONTROLLED by the modulation input.
 

Toke

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Sorry if I was unclear.
I am used to equipment that power all their signal in channels.
A radar will have two wires with 24V on for log signal, the log unit have a relay shorting them with some frequency.
A PLC will have e.g. a +24V and in connector for each channel.
A fuel centrifuge can be stopped by a relay in the fire alarm system.
A motor controller give it's own supply to an external speed setting potmeter.

It just look a very small saving compared to the additional work for whoever is commissioning it.

As for danger I was thinking of not being certain of ones relative voltages, this makes it even more important to ensure a common ground.
Sloppy!!! :mad:
 
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LOL - I didn't even think of that! I have several PC power supplies sitting in my "bone yard" right now. I will test which of the leads are 5 volt. Thanks for the tip :)
Red & Black
But the output may not be 5V without a sizable load on it. Most switching supplies require a minimum load.

If you have a DC wall wart power supply that is above 5V, you could do a ~1K resistor -> 5V zener + Capacitor as your ref voltage.

Does that Analog version turn on if nothing is connected to the control leads?

I have the TTL version, which is pulled-up so it defaults to ON.
 

Toke

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At least some of those PC supply's require a signal from the motherboard plug to turn on the rest of them. Documentation may not be easy to find.

So if it does nothing, measure for power in the motherboard plug.
 

dnar

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Assuming you have an ATX power supply, here's the pin-out. If it doesn't turn on, connect pin 16 to ground. Older PC power supplies don't have these control signals.


ATX - Wikipedia, the free encyclopedia

Let us know what you find to work with.
LOL, you beat me to it with the same link. 100% correct, tie the green wire to ground (black) and it will switch on.
 

qumefox

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Keep in mind PC power supplies require a decent load on the 5v supply to regulate very well. At least an amp generally.

And Toke, the things your talking about are pretty much standalone pieces of equipment. These modulated lasers are pretty much meant to be components of a larger system. The output bank of your PLC, the antenna in your radar, etc for example. These lasers are meant to be used in projectors, etc. Therefor they generally need other components to function properly.

If you want a standalone laser, you buy one that doesn't have modulation.
 
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And Toke, the things your talking about are pretty much standalone pieces of equipment. These modulated lasers are pretty much meant to be components of a larger system. The output bank of your PLC, the antenna in your radar, etc for example. These lasers are meant to be used in projectors, etc. Therefor they generally need other components to function properly.

If you want a standalone laser, you buy one that doesn't have modulation.
Exactly right. These lasers are designed to be used in ILDA-compatible laser projectors, which is why the modulation input is not self-powered. They are not stand-alone lasers, but they can be if you buy a TTL version or apply 5V to the mod inputs in the case of the analog units.
 

jupiter8

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Mine arrived yesterday - the analog modulated version - packaged thoroughly, exactly as advertised. I have no way of measuring the power output unfortunately but it's significantly brighter than my 95mW CNI pen. I powered it up, using a 5v signal from a computer PSU with two pots between the 5V line and the earth, tuned to 5V. A couple of times it has hopped into another TEM mode, maybe TEM01, I dunno, but then hops back to TEM00. It's pretty damn cold here at the moment, I think it's running too cool. I say this because once it warms up a bit it stays firmly in TEM00... anyone else noticed anything like this?

I've played with the focus a bit and I think I've improved the divergence a smidgen. I'll make a measurement when I get time to compare with what others have reported.

It's a nice little unit, very happy with it for the price.
 
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A couple of times it has hopped into another TEM mode, maybe TEM01, I dunno, but then hops back to TEM00. It's pretty damn cold here at the moment, I think it's running too cool. I say this because once it warms up a bit it stays firmly in TEM00... anyone else noticed anything like this?

That's very common with DPSS lasers. As long as it's stable once it's warmed up you should be all good.
 

Toke

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I have just picked up mine on the post office. :D

It is the TLL version, normally on, switches off the beam and rev down the fan a bit when I short the modulation/signal wires.

What a beautiful beam, and pretty solid, even in daylight. :drool:
 

dnar

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I have just picked up mine on the post office. :D

It is the TLL version, normally on, switches off the beam and rev down the fan a bit when I short the modulation/signal wires.

What a beautiful beam, and pretty solid, even in daylight. :drool:
Just lovely, isn't it.
 




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