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300mV is very strange and yes the output cap does provide power through part of the cycle. without the output cap, you would just get a heap of high voltage spikes. the output cap sucks up voltage and provides power in between the spikes. so if you are not using a large enough cap, your...

I would say that Drlava's flexdrive has that soft start feature built into the chip. I don't think it is important to have a soft start of 1s... laser diodes are designed to be pulsed anyway. turning them on in a fraction of a second isn't going to hurt them I find it annoying when a laser...

hmm i would say its the output capacitor. put a 10uF ceramic or tantalum on the output as well. FB voltage should be constant at 0.19V I reckon its struggling to keep it constant because of the output cap

what are you using as a load for your tests? try using a 20ohm resistor as a load, and a 1 ohm resistor as the sense resistor. you should be reading 3.8V across the load. and never power up the circuit without a load

I was joking, damn emoticons. i needed one that winks and raises its eyebrow at the same time... or something

why would someone do such a thing?  :o wait, thats not the emoticon i want to use, try this one :-?

how are you going to secure the aixiz module in the head? machine a ring to fit? that battery contact board, does it fit inside the head section? if it doesn't then when you screw the head on, it should get wedged up against the body, no glue required. otherwise if you have the body of the laser...

it is just a voltage booster, which is designed to regulate current. but you can set it up for constant voltage (I think)

here is the eagle file

sure, here print at 13% (well at least 13% works under linux, but i tried printing with windows the other day, and they came out slightly smaller. so you will need to use trial and error, place the chip on the printout and see if the pins line up. Or just download eagle and print from that)...

yeah definitely take it easy on the paste. i should take some photos next time.

ahh ok 0.4 ohms... yeah i never made a schematic, too lazy  ;D well I made schematic, but for another chip, so i just copied that. a few uF would probably do for the amps cap about physically making these things... i use the direct toner transfer technique, and etch in ammonium persulphate. it...

price would probably be around $15-20

he he. I Did throw a board together a couple of days ago, http://www.laserpointerforums.com/forums/YaBB.pl?num=1212653254/96#103 its pretty much the same but without the pot. and i haven't calculated the resistances. well done, it looks good except you might want to make the 1.4ohm sense...

no the TPS61200 has a max output of 5.5V

do you know what a Voltage divider is? its two resistors. i think you can make them fit ;) see http://en.wikipedia.org/wiki/Voltage_divider you want to set Vin to 7.5V-9V Vout to 0.29V and you want R1 and R2 to be in the order of Kohms

yeah this version is better ;) the link you posted is not current regulated, he has it set up as a 5V supply with a resistor to limit the current. the current changes as the LD heats up etc... its a lot safer to run laser diodes with constant current I am working on it

you could try putting a large cap on the output and using a resistor to set the current.

read the datasheet! it has plenty of examples to make it regulate voltage, just rig up a voltage divider between the output, feedback and gnd the LM3410 is not the most practical of chips if you don't want to keep things really small. there are plenty of through hole or SOT style chips that...

they are not marked in any way. sometimes the bigger ones don't even have a larger value. you can use an educated guess, caps that look like they are on a power line might have a larger value. I just ended up de-soldering heaps of them and measuring them. you could put the board in an oven at...