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Controlling a cheap TTL RGB module.

FishBulb32

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Hello again.

I’m thinking of getting a cheap RGB module to play with. At first I was tempted to get my hands on a cheap 505 as my next laser as the colour has always drew me in. But then I noticed various cheap RGB modules too. And looking closer at them I found that this one uses 505 for the green anyway:


So I figured this would be a good way to get both 505 and something that I will enjoy working with more and hopefully learn something from.

At first I figured I’d be happy with the simple 7 colours you get from this type of module. But looking into it more, I’ve come across a few comments on here where people have mentioned PWM. Now I don’t know much about this subject yet. But I wanted to clarify if the module I’ve posted will work if I built something using PWM to control each colour. Could I get more control of the colours. I understand this won’t be true analogue control, only pulses of on and off. And even if it gives off a stobe effect as it moves around might be a fun thing to control. If indeed that’s what will happen.

Another thing I spotted somebody mention was a search on eBay for “5V PWM generator”. From what I’ve seen I am thinking of having one for each colour with a dial to turn each one up and down.

Am I anywhere in the right ball park with this stuff? If not, is there any easy way I could get better control from this module?

Thanks for any help.
 



paul1598419

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I built a control unit for these type of RGB lasers. It used a separate pulse width modulator for each color at 2.4 kHz. At that frequency or even a higher frequency you won't see any flicker. I looked at each of the three RGB lasers in the link you provided and the 800 mW looks to be the same as the 1000 mW one. The difference is the current setting on the driver board for each laser. If you bought the 800 mW one you should be able to increase the current to each laser and have the 1000 mW for the cost of the less expensive one.
 

hakzaw1

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OR.. buy one w/ a driver for analog modulation.. 0 to 5 vdc for each color- millions of shades. --But looks like you have yet to see 7 colors.

.'' A while back I could never get my head around having a device that could produce such cool looking light then paying for glasses to block it all out. Personally I’d love to... ''

^^^^ read that again.. the glasses are NOT for 'enjoying a laser' (like at a show or concert)-- only the 'workers'(operators) wear eye protection-- for your purposes there are only few times when you MUST be protecting your eyes. Like placing the laser dot on the LPM SENSOR (use lowest power until aimed right) or measuring the beam for the numbers you need to find divergence.

IF you get a RGB there will be times when you must wear protection for your eyes-but not all the time..-they hardly ever arrive well stacked. not a perfect white dot at all.. so you adjust to make the a 'tighter stack' and to do that you must look closely at the 'dot' with glasses..
wrap yer head around that.
hope this helps..

could you please add your general location into your profile? thanx


hak

in Texas
 

FishBulb32

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Thanks for the confirmation, Paul. And what you’ve said about the 800mw and 1000mw is very interesting. Unfortunately cost is a huge factor here due to saving this year. I really dont have much of a budget this year, that’s why I’m looking for something cheap but different enough to keep things interesting. So I’m only really considering the 300mw one for now.

RedCowboy, that’s exactly the kind of thing I’ve come across. So again, thanks for the confirmation.

And hakzaw1, I should’ve put more emphasis on the cost of these things. I figured somebody would suggest analogue. From what I’ve seen of the cost of those things, they are just way outside my budget. I’m really looking for the cheapest options here.

And my previous comment about needing glasses was just really to give an insight to how I used to think and why I never bought a high power laser years ago. Of cause, over the years I’ve learned loads about lasers and safety. I now know how to respect and enjoy lasers. I have green and blue safety glasses already. Oh, and location updated!

One last question. If I were to get three adjustable PWM generators. Is there anything I can do to cause any damage to the lasers? Or would I be free to just mess about with the frequencies to see what happens to the light? Anything I need to be avoiding?

Thanks again!
 

ArcticDude

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If you want simple FX control for that 300mW RGB unit, I recommend to get one Big Clive RGB controller.
I can PM you modification instructions for that Big Clive PCB..
Here is same sort of El Cheapo RGB unit in action with Clives controller with HDD XY scanner

 

FishBulb32

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Wow, that’s a blast from the past. One of my first ever LED projects was Big Clive’s RGB floodlight. Learned a lot from that many moons ago. In fact, I might even still have it somewhere. Maybe I already have what I need, I’m sure it was based on that controller. I remember his patterns being very robust.

I would very much be interested in learning how to make use of one of those controllers. Being able to reproduce the effect from that video would be perfect. I’m physically capable when it comes to electronics but I’m not the best when it comes to the technical side. So reading schematics etc isn’t my bag, so hopefully what you have in mind isnt too advanced.

Love your photography by the way. One of the main reasons I’m doing this is to be able to mix landscape night photography with lasers.
 

ArcticDude

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Ok, give me shout when you receive the RGB unit.. Need to see driver board first :)
 

FishBulb32

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Quick update. I’ve gone and ordered the 300mw module. I’m actually really looking forward to it. I’ve noticed that the red laser is 638nm. I’ve only had 650nm reds in the past. So I’m actually going to see two new wavelengths and the ability to mix RGB too. Bargain if you ask me!

I’ve also found my old Big Clive RGB controller too. So I’m all ready for some help once it arrives. 👍
 

paul1598419

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When you get your RGB laser could you take a photo of the inside. I want to see if Laserland has changed the way they align the three beams. The one I got uses one mirror for each of two of the colors, but you are only given the rotation of the mirror for alignment purposes. It made it difficult to get the beams perfectly aligned.
 

FishBulb32

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Yeah, I’ll get some photos for you. I’m interested to see how these things look anyway. I’ve never seen dichroic mirrors in action.
 

FishBulb32

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It’s arrived. Very fast shipping!

I was under the impression that just giving it 12v would give me a white laser. Is that not the case with this unit? I’ve got nothing once giving it 12v.


EDIT:

Its working fine. I tried a different power supply with lower amps and it’s running great. Am able to turn all the colours on and off.

I’ve got a 3 channel PWM controller turning up in a day or two to play with. And hopefully be able to get Big Clive’s controller working with it too.

I’m gonna go back to testing it out. I’ll try and get some photos and do a little review when I get time.
 
Last edited:

paul1598419

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If you bought an off the shelf PWM make sure you only use it with a +5 volt supply. Otherwise you will get pulses that are too high. TTL is a +5 volt switch.
 

GSS

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Paul, this brings up a little bit off the cuff question..
I'm using a Wall Wart 12V at 1.88A to run the 505 mini labby I got a couple months ago..
Silly question, if I were to run a lower amp wall wart would there be laser power difference?
 




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