# Electronics laser diode

Discussion in 'Modding' started by zer0_c00l, 1 Mar 2005.

1. ### zer0_c00lWhat's a Dremel?

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hey i want to know how will i get this to run off the psu of my comp
and which leg goes where heres a link to the datasheet (.pdf)
laser_data_sheet

2. ### Bandit_zoraKWhat's a Dremel?

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where'd you get it and how much? Neways, I think that is too much amperage for your psu, unless you have super beefy one.

3. ### zer0_c00lWhat's a Dremel?

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its millamps is it not and 19.95aus\$ from www1.jaycar.com and then laser doides
what parts do i need to pull do the voltage and to get the ampage right???

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wts @ amperage

your power led uses about as much current that diode uses

5. ### Bandit_zoraKWhat's a Dremel?

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yeah I suppose it looks like it helps to actually look and what he circled (ie units).

6. ### zer0_c00lWhat's a Dremel?

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so guys what do i need

7. ### infernisWhat's a Dremel?

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Let's see, 2.3 volts at 45 mA. We can treat the diode as a resistor, but the value changes as we change voltage or current. Anyways, at 2.3 volts and 45 mA, we use Ohm's Law to determine the effective resistance at these parameters:

R = V / I = 51 ohms

Now we must add another resistor to form a voltage divider that will provide the desired voltage of 2.3 volts. Assuming we use a 5 volt DC supply, we need a resistor division ratio of

2.3 / 5 = 0.46

Now we assign an unknown variable R1 to the series resistor connected to our diode, and we consider the diode's effective resistance to be R2.

0.46 = R2 / (R1 + R2)

We know R2, so we solve for R1 and get R1 = 59.87 ohms. The closest available value would probably be 62 ohms for R1. Again, R1 is placed in series with the diode, so it would go

Code:
+5 V ----/\/\/----|>|----- GND
R1	   D1
Correct me if I'm wrong, I am a bit sleep-deprived.

8. ### zer0_c00lWhat's a Dremel?

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and which legs do i use cause wtf is the photo bit???

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10. ### zer0_c00lWhat's a Dremel?

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wtf what are the values of the resistors and where do they go sry for the bluntness but yea

11. ### SteveyGElectromodder

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(5-2.3)/0.045 = 60 Ohms. -> 68 ohm, 1/4 watt resistor.

Connect a resistor in series with one of the legs of the diode. Then connect the whole lot to the 5V supply in your PC.

12. ### SmilodonThe Antagonist

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I think that driving a laser diode is a bit different from normal LEDs... I think they need some cind of regulator circuit. That's what the photodiode leg is for.

I also believe that you will need a lens for that...

Please correct if i'm wrong

13. ### cpemmaEcky thump

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Try substituting 'please' for 'wtf'. Remember, you're the one asking for help.

The diode is the type used in cd players with a laser transmitter diode and a photo pick-up diode for the reflected signal.

14. ### SteveyGElectromodder

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A resistor is sufficient for limiting current to the laser diode.

The photodiode leg is for the built-in photo diode

15. ### zer0_c00lWhat's a Dremel?

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sry for being rude so all ineed is a resistor and that will lower the voltage and the current to 45mA and 2.3V

16. ### DarkInfernoMinimodder

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you got it eventually

17. ### zer0_c00lWhat's a Dremel?

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yay all ineed is a 62omh resistor this is one long thread for all that sorry again guys i am a bit thick

18. ### foxxWhat's a Dremel?

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On the pinout you nead to connect the resister to the five volt then the other end of the resister to the middle pin then have ground on the bottom pin. But what are you doing with this baby, she could put an eye or at least cause some damage.

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