Way to make "Turbo" button for DIY red burner?

While messign with my DDL circuit with a Senkat diode attached, I found that if I made certain adjustments, the laser could either stay at low current and remain cool, or instantly jump to higher current and get warm by jumping connection points in the circuit. This got me to thinking of hte best way to make a "Turbo" button for my burner that would allow me to keep it at say 160mA, where it would stay cool, but visible for aiming, then push a momentary switch and have it increase the current to say 250 mA, and back down when momentary is released. Would the best way to accomplish this be to put another resisitor in parallel with the 2 10 ohm ones when the button is pushed. For example, have the 2 10 ohm resistors in parallel putting 5ohms there, then when the momentary is pushed, have it add a 3rd 10 ohm resisitor in parallel, dropping the load to 3.33.

Any thoughts? Basically it takes me a while to focus and aim from distance and I would like to keep it cool in that time period, then have the power when needed.

desslok said:

Basically it takes me a while to focus and aim from distance and I would like to keep it cool in that time period, then have the power when needed.

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I too like to drive my LDs a little softer while I am trying to focus or aim them; but I normally just use a potentiometer to adjust the current to the LD.

If you want a simple two-setting (stun or kill?!?!? LOL) driver, get youself two 1/2 Watt 5 Ohm resistors (or four 1/4 Watt 10 ohm resistors), a NO (Normally-Open) momentary switch, and a ceramic or tantalium .01 uF capacitor.

Replace the sense resistor in your LM317 circuit with:
From Vout to one 5 Ohm resistor (or two parallel 10 Ohm resistors)
From the other lead of that resistor to the other three components all three of which are in parallel
from the other leads of those three components in parallel to the Adj pin.

Another way to say it would be:
Make the switch, capacitor, and one resistor into a parallel pack
Add that pack in series with the other resistor
and solder in as the sense resistor in your LM317 circuit.

Now, with the switch open, the sense resistor is 10 ohms giving your LD 125mA assuming that you're supply voltage is higher than 6V when under load. But when you press the switch, the sense resistor quickly becomes 5 Ohms sending 250mA to your LD.

How does that sound?

a_pyro_is said:

[Now, with the switch open, the sense resistor is 10 ohms giving your LD 125mA assuming that you're supply voltage is higher than 6V when under load. But when you press the switch, the sense resistor quickly becomes 5 Ohms sending 250mA to your LD.

How does that sound?

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Yeah, that's exactly what I'm looking for. Cool thanks! I'll give that a shot.

Let us know how it turns out.

a_pyro_is said:

(stun or kill?!?!? LOL)

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Kill what? Probably the diode...

now if I were you, I might want to use 2 switches, one thats push on/ off, and then a momentary switch for the "turbo"

i'm going to try this

jamilm9 said:

i'm going to try this

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When you do, be sure to make a new thread in the Experiments & Modifications board about it.

I think this is a great idea, and it could create opportunity in many DIY laser projects. If your able to successfully make this work just as you were planning, you should make sure to post your results and suggestions! I look forward to hearing about it