Circuit related, thought there might be interest here.

https://www.nature.com/articles/srep40074

 

My city had many bats flying around at sunset eating mosquitos. But there was not enough bats therefore there were still too many mosquitos.
Then my city put some larvicide in all the street drains and caused all the bats and mosquitos to be gone!

 

If I were peer-reviewing that article I would be asking why there is no research on the optimum wavelength, except a two line statement that 395nm LEDs are more efficient than 365nm.
LEDs can me made to emit any almost any wavelength, but previous products relied on a convenient line in the mercury discharge spectrum.
There also seems to be no effort to find the peak frequency, testing only a 6 spot frequencies. Is, for example, 75Hz significantly better or worse than 64Hz, or is the peak below 64Hz; or does it correspond to mains frequency; and, if so, why?
So, Nature, was your peer review panel asleep, or did it consist solely of the best friends of the authors?

 

Insofar as the frequencies tested.. I had the same thought. Those people must not be Amazon shoppers lol.

 

Insofar as the frequencies tested.. I had the same thought. Those people must not be Amazon shoppers lol.

I agree with you. It’s not exactly difficult to produce PWM at any frequency!

 

I happen to have a cheap zapper whose bulb failed. And since I can't find a replacement I think I'll order some leds and see what I can do with that PWM generator

 

I happen to have a cheap zapper whose bulb failed. And since I can't find a replacement I think I'll order some leds and see what I can do with that PWM generator

See if you can find LEDs of different wavelengths and get a paper published in Nature.

 

See if you can find LEDs of different wavelengths and get a paper published in Nature.

lol, yeah Im not gonna do that.

 

I'd like to see a chart in steps of 10's rather than in doubles. 30Hz, 40Hz, 50Hz and so on. Between 64 and 128 hertz there's a wide range of unexplored possibilities. Maybe the optimal frequency might be 96Hz.

Also, the comparison expressed factors in terms of 1.8 times more mosquitos using LED versus FL's. I don't have a bug zapper. If I zap 10 mosquitos in a night then jump up by 1.8 times then I'd expect to see 18 mosquitos captured. In advertisements I see bug zappers that show what appears to be a pile of cat hair from multiple brushings - which doesn't mean a thing to me. Those mosquito balls appear to have hundreds of mosquitos if not a thousand or more. But was that in one night or one month? Year? 10 years? Who knows?!

PWM controls intensity. But aside from the 64Hz comments I'd imagine PWM to be on the order of 2KHz. Is this article suggesting using PWM running at 2KHz or 64Hz?

 

I happen to have a cheap zapper whose bulb failed. And since I can't find a replacement I think I'll order some leds and see what I can do with that PWM generator

Probably it was a mercury vapor bulb UV generation scheme, and because eating mercury light bulbs is unhealthy, they are no longer available.