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555 Timer IC

ShinyThings

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Has anyone tried to incorporate a 555 timer IC into their driver design? :-? I was thinking of trying it with SenKat's GB diodes. I think it would allow me to get a bit more power from the diode without killing the life expectancy.

Any opinions?
 



Hemlock_Mike

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This pulse drive has been discussed before. Try it and let us know how it works. Any experimentation is good for all. Let us know how it works.

Mike
 

ShinyThings

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Well Mike, I've seen discussions about complicated circuits trying to get pulses down to nanoseconds. The 555 can give you a 1ms 50% cycle in astable mode, and is a lot simpler than what I've seen around here. 1ms pulses should give you enough delay to provide cooling and still not have an apparrent flicker.
As soon as I get my GB diodes, I'll start and see what comes of it. I will update this post with photos and circuit diagrams if all goes well.
 

a_pyro_is

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Are you going to try to send the 0.001 Second square wave to the Vin of a LM317?
 

Daedal

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That might not work... ::)

I've toyed around with pulsing LD power... but I honestly wouldn't use it unless the LD is a BluRay. Red LD's are mainly used for burning... and to do that you'd get a much better return with CW ;)

--DDL
 

ShinyThings

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a_pyro_is said:
Are you going to try to send the 0.001 Second square wave to the Vin of a LM317?
I would send the regulated current through the 555. The IC doesn't affect the current. It just chops it up into a square wave. They are reletively easy to use. The diagram shows a sample astable circuit.
 

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ShinyThings

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Daedal said:
I've toyed around with pulsing LD power... but I honestly wouldn't use it unless the LD is a BluRay. Red LD's are mainly used for burning... and to do that you'd get a much better return with CW ;)
I'll be the first to admit that I am way behind the curve on lasers, but from what I've read, the GB diodes are putting out around 80mW on CW. This is to insure that the diodes don't overheat and burn out prematurely. In a pulsed circuit, they can be driven harder. They are rated at around 250mW pulsed. If I drive it at 250mW, even assuming a 50% loss in average output, I would still be 45mW above the CW output, right?

This is my first project after a lot of study, so any input is helpful. It just seems counterintuitive to me. What have you used for pulsing a diode? What kind of results did you get?
 

Daedal

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As a matter of fact, we care not driving the diodes at 80mW. If you looked across the forum, we're powering it with 250mA or more... that already gives a minimum of about 150mW based on the spec sheet ;)

What I used for pulsing before was a comparator (LM139, the LM339 is available in RS) and a simple pulse circuit. The other thread about this has the scope output pictured.

--DDL
 




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