Do you have a reliable way to confirm the laser is still working? I built a driver that combines both, using 2 LM’s, the first configured as a variable voltage regulator to feed the one configured as a current regulator. Things New member Mar 14, Cheap, no battery to wear out, easy to use, goes anywhere, can’t break — especially useful for the right IR bands. The circuit of the Laser Driver: Home Questions Tags Users Unanswered.

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Fri Jan 13, 2: Glenn W9IQ 5, 5 Email Required, but never shown. Can I use multiple of them in parallel like this, or should I completely scrap this schematic? If you have a regulated 5 volt supply, you can simply put a ohm, or slightly larger, resistor in laesr with it.

Fri Jan 13, 8: The supply voltage is 5V measured 4. Each of the other seven switches adjusts the output voltage by 1.

Homemade Laser Driver with LM317

To push less current, best to put a shunt resistor across the laser; currents from LM output must be over 5mA, preferably 10mA, for internal bias. I have shorted them as of now.


Just the same way I shown in the previous figurethe source is from a 12V lead acid battery with 7. Jun 6, Posts: Sign up or log in Sign up using Google. Don’t know where it is – maybe in my vacuum tube drawer The total dissipated power will be For a better experience, please enable JavaScript in your browser before proceeding.

Jan 13, Posts: Mon Jan 16, 1: If you use a pot to make it variable like I did, make sure that you include an extra one ohm resistor in series with the pot so that you can’t make km317t value zero, it will always be the pot’s value plus one ohm. Input voltage is pulled directly from the 5V line of the microUSB port.

From wifi llaser, to high spec lab equipment. I expect that regulator would do the right thing, and if it didn’t, that filter cap should cover the difference. When you “connected the laser only momentarily” if that means timed according to human scales, you could have destroyed the laser.

I don’t know much about laser diodes though, so I am not sure what sort of sensitivity they have to any of that. While this circuit may not be as efficient as an LED driver module or a switching solution the LM is cheap and readily available. The set up of my experiment so far: This might not do what you want, anyway. Joined Sep 12, Messages 9, Likes lqser, Points The LM is not an appropriate choice for this function – it is not regulating anything om317t, as earlier comments have stated.


That seems pretty good for something like a laser diode. The LM needs to have the supply voltage 2 to 3 Volts above the output voltage.

Homemade Laser Driver with LM – Blog

Help with LM laser driver. You might have to be careful with this circuit to be sure it can exit the DISABLE state without momentarily applying the whole V3 voltage across the laser. The attached datasheet has a set of curves on page 7 called “dropout voltage” that illustrates this point: IsaacT New member Apr 30, But hey, almost free stuff tumbler.