adgmeijin said:
thanks for the suggestion, i use circular plastic ON/OFF switch that actualy perfectly fit on the aluminum tube ive use. on the battery, can i use a rechargeable 3.6v AAA size battery, like others using in their DX host? here in my country its hard to find parts to make a boost driver, so im using only compressed DDL driver at size of 15mm x 20mm using double sided PCB board. if you have an idea on how to make a simple boost circuit, please guide me, cuz now i dont have yet enough money to order finished boost driver. i hope you or somebody can give me some idea on this boost circuit, thanks.
Of course you can use 3.6V rechargable batteries with a 317 driver. You need two of them for red lasers and three of them for blue rays. Their size doesn't really matter, only the voltage and the capacity. You select the size depending on what you have place for and how long you want it to work.
The 317 driver needs 6V OR MORE. It doesn't really work from two 3V batteries. Batteries drop in voltage as they slowly discharge, so with two 3V batteries, the driver would drop out of regulation almost from the start, and would not really provide a constant current. (Maybe you know that, and were only asking about the size)
The boost driver can be hard to make, because to make it small you would need SMD components. Sometimes the boost IC has no legs, and is next to impossible to solder by hand. I work with electronics, and i still managed to kill one when soldering a legless IC by hand.. Another problem is, that you can't really buy SMD components one by one. You'd have to order samples of the IC and the inductors, and then you would have to scavange through old electronic devices for SMD resistors and capacitors. The SMD capacitors have no markings, so you would need a multimeter, that can measure them. In the end, you would have to etch your own boards, and solder everything together.
Honestly, buying Dr_Lava's buck/boost driver is the best thing you can do. He is selling it for $20 and $2 for shipping anywhere, regardless of the number ordered. I think $20 is a VERY good price for what it can do. Just the components could cost you more, unless you ordered in really large amounts. And if you compare this to the fact, that some people are selling parts for a 317 driver for $15, Dr_Lava's drive is almost free for what it can do.
Only a buck/boost driver can drive ANY diode from a single Li-Ion cell. So you can use a slightly larger battery with more capacity, but the final laser will still be smaller, simply because you only need one battery. And compared to linear regulators, the buck/boost driver drives diodes at a VERY high efficiency, while a 317 is complatelly wasting more than half the batteries and turning their capacity into heat (not really a bad thing, just how it works).
