Search results

Drat! I don't have an LM1117 in my parts bin. I can't reproduce this surge with an LM317. I've got to pick up some parts in the next day or two though. I'll pick up an LM1117 or 2 and try to reproduce the problem. (Now that I'm all curious...) I want to see this on an oscilloscope. cheers...

You are right. It's C2 causing a time lag in the response of the driver.  I'd remove C2 completely and use a smaller C3 (1 microFarad perhaps) Try it on a test load first of course. And always remember- Free advice is worth what you pay for it ;) Cheers, kernelpanic

I wasn't suggesting altering the input cap. I was saying remove the sense cap and reduce the output cap. Scr*w the datasheet. Breadboard it then rip on me... cheers, kernelpanic

Normal mosfets like the 2sk1112 will work. But a logic level mosfet (like an IRL-510) will work better for battery powered circuits. Also I recommend NOT using a pot to adjust power on the fly. Better to use fixed resistors and a momentary SPDT push-button to activate 'burn mode'. (Schematic...

Hello All, I can think of a couple that haven't been mentioned: 1. Optical Trapping- This is one of the coolest things to do with a handheld burner. It works with every wavelength I've tried. One basically focuses the laser very close-in (FP in inch or two from the lens) burn something and...

Don't actually expect shipping to be cheap for this! There's no way they'll be able to honor that shipping price. Either the shipping calculator is broken or the seller did not correctly state the size/weight of the item. I've watched a few of these go by and shipping is more like $300 than...

Oops! I just didn't want it going to a reseller or (gasp) someone who might actually use it to sequence DNA... :-? Good Luck! kernelpanic

I posted not because of what it does (sequence DNA), but what it contains-> An Argon laser. ;) cheers, kernelpanic

Anyone around Berkeley, CA there's a sequencer on ebay that looks promising... http://cgi.ebay.com/ABI-Prism-377-DNA-Sequencer_W0QQitemZ380099054812QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380099054812 cheers, kernelpanic

Re: Simple Adjustable Laser driver (V. 2) It Works Andrea87 posted one here- http://www.laserpointerforums.com/forums/YaBB.pl?num=1231275597 cheers, kernelpanic

I've used both Radio Shack RCR123's and Ultrafire 16340s (both protected) in my dorcy jr. builds, they fit fine and work well with the flexdrive. (Not to mention they are far more cost-effective.) cheers, kernelpanic

I agree. The driver I posted was from the first laser I built. I was unhappy with the dropout of the LM317. I knew I could do better with a mosfet and an op-amp. (BTW it's still running strong at 135mA after 100+ hours :) ) But I don't think a home-made boost driver would be much larger or...

Very nice. I like! I even have a spare diode to try it. I had always meant to switch the Vref to a zener. Been too busy playing with vacuum tubes lately... +1 4 U for sure. ;D Cheers, kernelpanic

Hello All, Mostly these days I play mandolin. But I have played guitar, bass guitar and fiddle. Lately though I'm designing/building a theremin. (of the vacuum tube variety...) Kinda on a steampunk kick. ;) cheers, kernelpanic

In the past 5 months I've built 10 lasers, gave 3 away, sold one, still own 6. (Gotta have a spare for each color in case I lose a diode/module ;) ) Oh, and also I built 2 spirographs. As to value, IDK. Depending on the host/color/driver they cost about $80 each to build, time not included. But...

O.K. Now you're beyond the LM317. It's meant to be a voltage regulator. If you're only talking about hundreds of cycles per second PWM (i.e. using PWN to turn colors on or off) you can get away with it. But if you want to smoothly blend or modulate beam strength, I'd try something different. Dr...

That's doable too if your brave enough to de-solder your 808nM diode. (I'm not...) Otherwise either option I suggested above will work. The first will go a little higher than 6V with the trimpot at 100 ohms. The second maxes out at 6v exactly to prevent overdriving the module. cheers...

That'll work. Make sure you use 1/4 watt parts as you've got around 1/8 watt going through constantly at 6v. If you've got only the 300 ohm pot, then do- resistor- 47 ohms trimmer- 100 ohms pot- 300 ohms. That'll get you close with the trimmer centered while still giving you linear response...

Niko is right but there's one caveat- If linearity isn't important then the 300/1200 combo will work best. If it is, then just use the 300 and don't turn it past 4/5. Here's why- Wiper Position Linear 300/1200 500/470 0 0 0 0 1/4 60 71...

on rodents?!  --> http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17960752 http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=DetailsSearch&Term=17374099 Rodent placebos- Rats of NIMH indeed! No one is saying sunlight doesn't have the same...