Power supply for multiple lasers

[zxn474l]

First let me say thank you for all those people that have given me genuine good advice on this site, but like any blog or any forum there will be those that only think the same way every single time ...like inside a box afraid to try something new, becuase it hasn't become commomn yet...WHY? I know I ask for info on here alot but I am willing to learn something new and try something new..."NOTHING VENTURED...NOTHING GAINED!" So with that said, if I have multiple diodes to spare say 10 each capable of 250mw + how can I cluster all these together to produce a 2.5 watt red laser using a single battery instead of taking 10 drivers and 10 9volt batteries and 10 switches because that is to cluttered up and waste space and I think it could be solved using resistors in a parallel circuit each giving same voltage and limiting current and having just one momentary switch to turn off and on. This will be a "pulsed" laser at 1-5 seconds not for use as a laser pointer. My goal is to get the diodes powered effectively and once that is achieved put the diodes in mini brass housings with glass lenes fixed to "infinity" in a cirular pattern so the beams are collimated and then use different convex lenses to achieve different focal points for burning...not a single beam here just ALOT of photons in a tiny spot that is adjustable! So if you can help with the POWER SUPPLY AND WIRING please give some advice on how to do this and what kind of battery to try and use, I would like a strong rechargeable battery like a 9.6 volt cordless drill battery so I don't have to keep replacing batteries...that would get expensive quick.

 

[lasersbee]

The safest and most reliable way would be to use a driver per Laser Diode...
(we all know that no 2 LDs are identical in characteristics).. This would assure
that each LD would be adjusted to your requirements...
You could build the DDL Driver circuits quite inexpensively... rather than buying
pre-fabricated drivers.. to keep the costs down.

Then You could power all the LD Driver inputs from one DC Power Source..
(ie. your 9.6V cordless drill battery)

BTW... you will have one heck of a time aligning 10 laser beams to one spot.


Jerry

 

[Jimmymcjimthejim]

You can use one battery to power multiple lasers. Although you can use one driver for all the lasers, it really isn't recommended because one diode could take 500mA and the other might be taking 200mA.
My suggestion would be to use two lithium batteries in series, for 7.4V. Then build ten DDL circuits. Order the parts online and you can get the parts for the drivers for like $2 each. All you need is the LM317, a resistor, and a capacitor.
Since you're using the same positive/negative ground for each driver, you can just put a SPST switch (make sure it is rated for a few amps!) right off the positive or negative end of the battery.

 

[dr-ebert]

Since you'd normally set all diodes to the same current anyway, you can just wire them all in series and use a single driver - that way they're guaranteed identical currents. Due to variations between diodes, they would all output slightly different amounts of power, but again, it'd be the same if they each had their own driver set at the same current.

One problem is that you'd need a pretty high voltage - the input to the driver (assuming a LM317 type linear driver) would need to be at around 38V. An advantage to having one driver supply several diodes is that the whole setup would be more efficient, as each driver converts a certain amount of power into heat. Fewer drivers = less loss.

For 9.6V batteries, you could use 5 drivers powering two diodes in series each.

For your 10x 250mW project, you'd need around 15W of input power, so you'll need pretty big batteries - power drill batteries sound ok.