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If it's got a pot, it's on the other side of the circuit board, next to the battery-contact/spring. The adjustment is 'backwards'. Counter-clockwise is more power, clockwise is less. But don't expect too much. These modules are usually set at the factory for maximum brightness. Turning it up...

Re: FS: lpc815 sleds(long open can diode)---13$ Payment sent for 2 sleds and shipping. Thanks again Drew. Cheers, kernelpanic

Hello All, There are suitable dichro's available in the sleds we get our diodes from. The phr803t sleds have a dichro that will pass green but reflect blu-ray. The DVD burners also have dichro's that may work to mix colors in a scanner... I'd put the green in straight through, then mix the...

For me, not so much as- 1) A good UV flashlight/forensic light costs as much/more than my laser cost to build. 2) My lasers use rechargeable batteries. 3) I've got several cheap UV flashlights. None of them light things up like the 405nm does. 3) Anyway, my pockets are taxed enough with all the...

Nice catch. The LM385 isn't truly a zener diode. So it might not act like one if reversed. But if it did, the voltage difference would be much less bringing the power down... I'd +1 your rep if I had 50 posts ;) cheers, kp p.s. I'm glad I came across this thread. I'm now looking into...

To troubleshoot, with the circuit on, check the voltage between Vout and Vref of the TLV1117, if it's not 1.25v, then it may be blown. Then check the difference between the anode/cathode of the lm385. If it's not 1.2v then it might be blown... Otherwise, check for solder bridges and the...

Hello All, I use my lasers as tools a lot. The 405nm is good for rockhounding as it lights up flourescent minerals. It also works for verification of currency and IDs. The green is useful for line-of-sight stuff like triangulation, distance and height calculations. (i.e.- point the laser at the...

FYI- The easiest place to find aluminum washers it the auto parts store. They are sold as oil-pan drain plug washers. I think Toyota generally uses 12mm... cheers, kernelpanic

o.k. that makes sense then... Your math is correct. Instead of measuring amperage, just measure the voltage across the 1 ohm resistor. Since Ohm's law is E=I/R and R=1 ohm, then E=I. means that measuring the voltage across that resistor gives you a direct current reading. (So if you see 0.2v...

drew, Payment sent for one in module. Thanks, kernelpanic

Here's how I calculated it- The 2.7k/100k resistor and the pot are a voltage divider in series across the LM385 which is a 1.2 volt voltage reference. The LM1117 will supply voltage until the Vref is 1.25v. So with the wioer of the pot turned all the way down, the difference(0.05v) presents...

z000z, The LM385 simply gives a voltage reference (either 1.2 or 2.5V depending on model) anode to cathode. The TLV1117 always presents 1.25v between out and adj terminals. So assuming that this circuit uses the 1.2v LM385, that leaves 0.05v across the 1 ohm resistor at the minimum POT...

Actually at 125mA, per diode, that's 625mA at ~5v for over 3 watts! cheers, kernelpanic

Indeed, Good Luck! kernelpanic

tw15t3r, You may just be running into the dropout of the LM317. At the low current used to drive the mosfet, there is probably 1.5-2.0V dropout. Meaning that with a 4.5V supply you can give 2.5-3.0V max to the gate of the mosfet. This may not be enough to open the gate all the way... (Even if...

Re: Simple Adjustable Laser driver (V. 2) It Works The resistor will work. But I think that C8 could cause oscillation. I totally understand what you're thinking. (op-amp filter) But that's for signals. A filter by definition will block some frequencies but pass others. Our 'signal' is the...

Got mine yesterday, everything shiny ;) Thanks Drew. cheers, kernelpanic

Re: Simple Adjustable Laser driver (V. 2) It Works You are correct. The voltage drop across the diode increases with current. Using a zener voltage reference would correct this... cheers, kernelpanic p.s.- Zom-B, Which resistor are you referring to? You say R11, but then you say 22k in the...

Re: Simple Adjustable Laser driver (V. 2) It Works Hello All, At this point I've tweaked the power settings, gone few 2 sets of batteries, then broke down and bought RCR123's.. The current supplied does change depending on supply voltage. But not as much a it would without the diode across the...

tw15t3r, The IRF510 was the first mosfet I used (for the same reason...). I also ran into the same problem. The logic level mosfets solved it... Just look for IRL instead of IRF on your part numbers... cheers, kernelpanic p.s. - I've got some logic-level mosfets (N-channel) surface mount), I...