Simple cheap lab bluray

[random person]

Hey... my first laser. Woohoo... Know I know its ugly... but it was cheap-ish =P

Driven with 150mA. Optical output = 110mW.

Anyhow, wanted something very stable and wall powered. Now if your a cheapskate you will be very careful on what companies and people around you throw out =)

Part list

power switch (dumpster dived)
pcb board (dumpster dived)
2uF ceramic output cap (dumpster dived)
47uf elec input cap (dumpster dived)
12V, 1A wallwart power supply (dumpster dived)
all wires (dumpster dived)
1/2in (12.7mm) brass pipe hose output (1.59 usd)
2in pipe extender used for extra mass to add to copper heatsink (2.09usd)
100ohm pot (.65 usd) Digi-Key - CT6EP101-ND (Manufacturer - CT6EP101)
5ohm sense resistors (.62 usd) Digi-Key - CWC-5.0RCT-ND (Manufacturer - CW02B5R000JE70)
lm317 (.85 usd) Digi-Key - 296-13869-5-ND (Manufacturer - LM317KCS)
heatsink for lm317 (1.5usd) Digi-Key - HS403-ND (Manufacturer - 513002B02500G) (this was a poor choice.. there better ones out there)
laser diode (14.25 usd) HighTechDealZ - 405nm SFAW210 Blu Ray Laser Sled
^^^ very good choice cause it comes with a high powered red also

im to lasy to add that all up or include everything such as the tape... =P Should be close to 20-25 usd total...?

Anyhow, thanks for looking.

 

[lasersbee]

Nice first Laser...
That Cast Iron pipe fitting must really keep things cool...


Jerry

 

[random person]

Nice first Laser...
That Cast Iron pipe fitting must really keep thinks cool...


Jerry

I assume thats fun ole sarcasm?

yup, it keeps me thinking pretty cool. =P Cast iron is meant to absorb heat from the brass pipe extender. The iron doesn't touch the laser module. Meant to couple heat from pipe bushing. Brass pipe bushing is 12.7mm in diameter so the module fits nice and snug in that. Combine that with thermal grease and a small bit of adhesive and I would think that makes a decent heatsink? Not sure how much 405nms heat up but this thing isn't getting very hot. Would have been better to have picked copper but it runs decently fine.

One thing I noticed on LPF is you guys don't rate your heatsinks? (not that i've noticed). I'd be interesting to test it. To test it I would throw a resistor in there at say 3 watts, jack it full of thermal grease so it has good connection to the heatsink. Then thermal couple the heatsink, find its rise above ambient, and then divide that number by 3 to find its rise per W? Am I thinking right there?

 

[Wolfman29]

I don't think you're right when it comes to rating the heatsink. Or maybe you are. When it comes to resistors being rated for power, it's how much power they can handle before they stop functioning.

So I guess you are right, because that power is being "stored" in the resistor. But, at the same time, you could just use a 3W resistor and then throw 1W of power into it and see how much the temperature rises above ambient, that way there is no division. That means, just load one volt through a one Ohm resistor. That way, it is transferring 1W of power into heat which is then what you can use to figure out how effective a heatsink is.

 

[lasersbee]

I assume thats fun ole sarcasm?

Man.... you seem to have a problem understanding what you
read...:undecided:

It was a genuine Kudos for your 1st Laser build and I stated
that the thermal mass of that Cast Iron pipe fitting should
keep the Laser's temperate low...

What do you see sarcastic in that....:thinking:
Or are you trying to troll me on your own Thread....:thinking:


Jerry

 

[random person]

Wolf, yes I would ensure to not exceed the max power rating of the resistor or supply. I would use umm 2ohm, 5W resistor then a 6V supply thats rated for more then 3Amps... that should do it. Assuming I thermally connect that resistor well enough to the heat sink I would be transferring 3Ws of power to the heatsink. Then taking the temp rise of the part (raise - ambient)/3W would give me a rating for the heatsink.

Man.... you seem to have a problem understanding what you
read...:undecided:

It was a genuine Kudos for your 1st Laser build and I stated
that the thermal mass of that Cast Iron pipe fitting should
keep the Laser's temperate low...

What do you see sarcastic in that....:thinking:
Or are you trying to troll me on your own Thread....:thinking:


Jerry

Sorry mate, my bad. Iron isn't exactly a very good heatsinking method (nor is brass but I believe its better then iron?) so I assumed you were pointing to that. Will try not to jump to quick conclusions in the future.

 

[divindavid]

Hey... my first laser. Woohoo... Know I know its ugly... but it was cheap-ish =P

Driven with 150mA. Optical output = 110mW.


Anyhow, wanted something very stable and wall powered. Now if your a cheapskate you will be very careful on what companies and people around you throw out =)

*snip*

im to lasy to add that all up or include everything such as the tape... =P Should be close to 20-25 usd total...?

Anyhow, thanks for looking.

What are you using the two HD44780 displays for?