What is a Duty Cycle

[Chainsaw574]

My laser is from dragon lasers and on the website they have a chart and my laser has a 3 minute duty cycle. after i turn it on it starts to feel warm after about 30 seconds. I saw online that it refers to how long the laser can be on without being turned off. So does this mean that for example I turn the laser on for 3 minutes then turn it off. How long should I wait before turning the laser back on? Also if the laser gets hot after a minute is that bad? (I always have the laser attached to a stand)
Thank you!

 

[GSS]

Yes it's basicly how long you should run your laser before turning it off for some cool down time.
Iv'e seen mentions of,
10 seconds on 5 seconds off
30 seconds on 10 seconds off
1 minute on 10 seconds off
I believe it better to equal the on and off time, such as 1 minute on and 1 minute off etc..
There have been some post's of Dragon lasers Duty Cycle claims, and the claimed 3 minutes they post seems very very high, unless it has a internal power shutdown in the driver..
If yours is getting warm/hot at 1 minute, than limit it to that 1 minute and give it a 1 minute rest at least.

 

[kecked]

For a cheap pointer it’s a measure of how cheap it was made. You should be able to run a 5mw laser essentially forever.
If it’s more than 5mw....it isn’t a pointer.

 

[Alaskan]

When I first became interested in this hobby, I was asking CNI for a high power 532 nm green pointer with 800 mw or higher output with a constant duty cycle, to my disappointment, they didn't make one. There is only one manufacturer of high power pointers I know of with a 100 percent duty cycle, Laserglow. They however were shut down from selling pointers to US citizens by the government, sadly. It's a convoluted thing going on with laser pointer companies, the FDA goes after some, and leaves others alone due to politics. Jetlasers has been able to send lasers to us, Sanwu too. In the case of Sanwu, probably because they haven't grown too big yet, JL remaining untouched is pure politics due to an individual with connections associated with that company.

Sanwu and JL are not in the US, while Laserglow is, easier to regulate them, but WickedLasers was outside of the USA and they were able to be shut down by our govt. by pulling everything in transit from their address.

 

[kecked]

that's why I said it isn't a pointer....in the USA it isn't a pointer if it puts out more than 5mw.
There is a limit to how much power you put in a handheld device both in terms of power supplied and power dissipated.
That wasted driver heat has to go somewhere. A more massive housing means more ability to thermally regulate for a longer time period
also if you ont couple the diode to the mass, it can't shed its heat effectively.

 

[Alaskan]

Understood, not a pointer. Laserglow had a lot of heat sink on their 100% duty cycle high power "pointers", but I shouldn't call it that, not at that power level, it is far too much to be used as a simple pointer and dangerous for that use for more than one reason.

 

[kecked]

really I'm being a USA snob dick. There is more to the world than the USA.

you make a good point however. If you drive the laser with a pulse it will be able to remain on longer and your eye will not likely see the dots
provide the driver doesn't stay on in class A all the time. In that case the heat is just duped instead of being used. try a pwm over 60hz

 

[Alaskan]

I know the yellow 589 nm pointers from CNI are pulsed to increase the apparent power to the eye and while having less heat to deal with.

 

[kecked]

don't start me on yellow. it's my obsession. I want to see a 10W 577nm laser. Will look like a beam of sunlight in the middle of the daylight.
Blend with 445nm to make a solid white laser stick!.....provide the air has the right particle dust moisture scattering....

 

[BowtieGuy]

Sanwu and JL are not in the US, while Laserglow is, easier to regulate them, but WickedLasers was outside of the USA and they were able to be shut down by our govt. by pulling everything in transit from their address.

Chris, If I'm not mistaken, think Laserglow is a Canadian Company.

Another US seller/reseller of "pointer" style lasers is Optotronics, they sell a lot of >5mW pointers that seem to do well with decent duty cycle times, but they are very expensive for what you get.

 

[Alaskan]

Jeff, I stand corrected, I believe they are indeed Canadian. I've been eyeing those Optotronics lasers for years due to the price.

That's my next hope, high power yellow, I might have hope springing eternal for one. I've been considering buying a 1319 nm YAG and combining with 1064 nm, but easier to make faux yellow combining two colors.

https://imageevent.com/qdf_files/te...randlightwavecommunications/589nmyellowlasers

 

[kecked]

Nope. Real yellow just has that something and for lumia athere is no other way. What are you considering 1319 1064
An lbo of some kind 1064 idler? Something like this? https://www.researchgate.net/publication/245464068_Diode-pumped_Nd_YAGLBO_CW_yellow_laser_at_5889_nm

 

[Cyparagon]

I'm nearly certain all these duty cycle ratings are made up.

The alternative is that the heat sinking is CONSISTENTLY between a mere 10% and 30% undersized, and not a single one of the designers ever thought to increase it that little bit.

1 minute on and 5 seconds off for instance is a duty cycle of 93%. If that extra 7% rise in heat is enough to destroy the device, you've made a shit device.