Disconnecting CFL bulb from powered circuit can cause damage?

I have a mosquito trap with a circline 10W UV fluorescent bulb and a fan, t he bulb went bad and it proved difficult to get a replacement. Now I would like to run the bulb only at night to extend its life and I tought to add a n LDR, some transistors and a relay to run the bulb only at night.

Problem is the same inverter runs the bulb (CFL like circuit) and the fan, and the fan must never stop. The inverter has separate transformers for the bulb and fan but the drive circuit seems shared.

My concern is if I can place the relay in series with one of the four bulb wires to turn it on and off safely. The inverter ran for several months wit h a blown bulb so it has no problem to run without a load. But can it be da maged if the bulb is disconnected while powered?

Reply to
Jeroni Paul
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How complex would you like this?

I'd separate things and run the fan from it's own power supply that also supports a circuit that

1) switches the fan off after the lamp has cooled, 2) doesn't allow the inverter to turn on if the fan is not running

A bit of simple logic, or a micro....

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Adrian C
Reply to
Adrian Caspersz

the bulb went bad and it proved difficult to get a replacement. Now I woul d like to run the bulb only at night to extend its life and I tought to add an LDR, some transistors and a relay to run the bulb only at night.

, and the fan must never stop. The inverter has separate transformers for t he bulb and fan but the drive circuit seems shared.

b wires to turn it on and off safely. The inverter ran for several months w ith a blown bulb so it has no problem to run without a load. But can it be damaged if the bulb is disconnected while powered?

a small halogen bulb also works to attract bugs.

NT

Reply to
tabbypurr

The fan is not for cooling. It is a mosquito trap and the fan sucks mosquitoes attracted by a chemical compound, heat and UV light. The fan must not stop or the mosquitoes will escape.

I forgot to mention it is a Jata MT8.

Reply to
Jeroni Paul

the bulb went bad and it proved difficult to get a replacement. Now I woul d like to run the bulb only at night to extend its life and I tought to add an LDR, some transistors and a relay to run the bulb only at night.

, and the fan must never stop. The inverter has separate transformers for t he bulb and fan but the drive circuit seems shared.

b wires to turn it on and off safely. The inverter ran for several months w ith a blown bulb so it has no problem to run without a load. But can it be damaged if the bulb is disconnected while powered?

Is there room to add a supply just to power the fan? If so, you can arrang e to power down the CFL inverter (even directly at the processing chip whic h usually has an enable line) when not needed instead of suddenly disconnec ting the load. This way, you would probably not even need the relay; use y our photocell and transistor to shut down the inverter directly.

I don't know if mechanically switching your lamp on and off will damage the lamp or supply, but my gut instinct is no.

Switching power at the processor IC will be safe for both.

Reply to
John-Del

As long as you understand that so-called "mosquito traps" based only on lig ht do not actually attract mosquitoes, you will find that any light will do .

The shocking trap has been demonstrated to attract primarily beneficial ins ects. From:

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Do Bug-Zappers work? Black light insect electrocution devices (Bug Zappers, etc.) are purchased in huge quantities by homeowners due to their demonstrated ability to attra ct and kill thousands of insects over a 24 hr. period. One industry represe ntative estimates that over 1.75 million of these devices are purchased ann ually in the U.S. But do they really control pest insects? Bug zappers do i ndeed kill some mosquitoes. However, the only two controlled studies conduc ted to date by independent investigators at the University of Notre Dame sh owed that mosquitoes comprised merely 4.1% and 6.4% respectively of the dai ly catch over an entire season. Even more important was the finding in both studies that there was no significant difference in the number of mosquito es found in yards with or without bug zappers. What is particularly disconc erting, however, is the number of non-pest insects that comprise the vast m ajority of trap catch. Many of these insects are beneficial predators on ot her insect pests. They in turn constitute a major part of the diet of many songbirds. Indeed, reduced numbers of moth and beetle prey species have con tributed significantly to the decline of songbird populations in many afflu ent suburbs. Insect electrocution devices undoubtedly bear some responsibil ity for this phenomenon. Mosquitoes continue to be more attracted to humans than to the devices. One study conducted in homeowners' backyards showed t hat of the insects killed by these devices, only 0.13% were female mosquito es. An estimated 71 billion to 350 billion beneficial insects may be killed annually in the United States by these electrocuting devices.

Let your conscience be your guide.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

On 18/03/2019 11:43, snipped-for-privacy@aol.com wrote: An estimated 71 billion to 350 billion beneficial insects may be killed annually in the United States by these electrocuting devices.

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Adrian C
Reply to
Adrian Caspersz

On 2019/03/18 4:43 a.m., snipped-for-privacy@aol.com wrote:

g as you understand that so-called "mosquito traps" ba sed only on light do not actually attract mosquitoes, you will find that any light will do..

king trap has been demonstrated to attract primarily b eneficial insects. From:

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e/faq

t electrocution devices (Bug Zappers, etc.) are purcha sed in huge quantities by homeowners due to their demo nstrated ability to attract and kill thousands of inse cts over a 24 hr. period. One industry representative estimates that over 1.75 million of these devices are purchased annually in the U.S. But do they really cont rol pest insects? Bug zappers do indeed kill some mosq uitoes. However, the only two controlled studies condu cted to date by independent investigators at the Unive rsity of Notre Dame showed that mosquitoes comprised m erely 4.1% and 6.4% respectively of the daily catch ov er an entire season. Even more important was the findi ng in both studies that there was no significant diffe rence in the number of mosquitoes found in yards with or without bug zappers. What is particularly disconcer ting, however, is the number of non-pest insects that comprise the vast majority of trap catch. Many of thes e insects are beneficial predators on other insect pes ts. They in turn constitute a major part of the diet o f many songbirds. Indeed, reduced numbers of moth and beetle prey species have contributed significantly to the decline of songbird populations in many affluent s uburbs. Insect electrocution devices undoubtedly bear some responsibility for this phenomenon. Mosquitoes co ntinue to be more attracted to humans than to the devi ces. One study conducted in homeowners' backyards show ed that of the insects killed by these devices, only 0 .13% were female mosquitoes. An estimated 71 billion t o 350 billion beneficial insects may be killed annuall y in the United States by these electrocuting devices.

r Wieck

Thanks again Peter.

One has to be careful of assumptions - I assumed t hese things were effective because the advertising s aid they were...

Age Of Persuasion indeed!

Gah! When will I ever learn?

John :-#(#

Reply to
John Robertson

On Monday, 18 March 2019 11:43:34 UTC, snipped-for-privacy@aol.com wrote:

ight do not actually attract mosquitoes, you will find that any light will do.

nsects. From:

formatting link

d in huge quantities by homeowners due to their demonstrated ability to att ract and kill thousands of insects over a 24 hr. period. One industry repre sentative estimates that over 1.75 million of these devices are purchased a nnually in the U.S. But do they really control pest insects? Bug zappers do indeed kill some mosquitoes. However, the only two controlled studies cond ucted to date by independent investigators at the University of Notre Dame showed that mosquitoes comprised merely 4.1% and 6.4% respectively of the d aily catch over an entire season. Even more important was the finding in bo th studies that there was no significant difference in the number of mosqui toes found in yards with or without bug zappers. What is particularly disco ncerting, however, is the number of non-pest insects that comprise the vast majority of trap catch. Many of these insects are beneficial predators on other insect pests. They in turn constitute a major part of the diet of man y songbirds. Indeed, reduced numbers of moth and beetle prey species have c ontributed significantly to the decline of songbird populations in many aff luent suburbs. Insect electrocution devices undoubtedly bear some responsib ility for this phenomenon. Mosquitoes continue to be more attracted to huma ns than to the devices. One study conducted in homeowners' backyards showed that of the insects killed by these devices, only 0.13% were female mosqui toes. An estimated 71 billion to 350 billion beneficial insects may be kill ed annually in the United States by these electrocuting devices.

Interesting. That's at odds with my limited experience of them. Both uv tub e with kilovolts & halogen lamp with hot bit removed the majority of flying insects indoors when I used them. What percentage were mozzies I don't kno w, houseflies were the main issue & catch.

I'm puzzled too by the talk of yards. Surely they weren't using them outdoo rs? If so no wonder they didn't achieve anything.

NT

Reply to
tabbypurr

Insects are attracted by warmth, not light. So any gadget won't win.

Reply to
Look165

Yeah, but insects like mosquitoes "see" heat, and most light sources emit light in the infrared band.

Reply to
John-Del

It seems that mosquitoes initially follow CO2-rich airflows to find food sources, switching to warmth/moisture/odour vectors as they home in, and finally using eyesight to find the best place for tapping into the victim's blood supply.

Several information sources say this: none say they use long-range optical or IR methods of finding their next meal.

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Martin    | martin at 
Gregorie  | gregorie dot org
Reply to
Martin Gregorie

I am going to get a bit snarky here, as there is an entire class of the pop ulation that are so confused by actual facts that they *MUST* believe the o pposite, or they will die.

a) Mosquitoes are poor flyers - generally as little as a 5 mph wind will gi ve them difficulties. A breeze/fan is your best local defense. b) Mosquitoes follow CO2, various scents and such in searching for their pr ey. Although they prefer warm-blooded prey, they will readily bite reptiles and amphibians should nothing else be available. c) Some individuals attract mosquitoes more than others. But anything that breaths with lungs is fair game.

Mosquitoes ARE NOT attracted to light. FULL STOP. If they get caught in a z apper-type trap, it will be mostly males (which feed on sap and nectar) or females caught simply passing through, not heading to a destination.

Zappers may be entertaining, but they are a plague on the insect population , doing far more harm than good - excepting those indoors, in kitchens and such, that kill mostly flies. The brute fact of the matter is that these de vices should be banned to the general public, and used only by license. As, clearly, the general public is far too stupid to understand the issue - re quiring a nanny-government to protect them.

No Bumblebees - no vine squash or melons. No Bees - not much of anything. No hummingbirds (protein source: Fruitflies, spiders and other small bugs, mostly), many fruits with tubular flowers would fail. Moths, butterflies, midges, beetles - by the way, no midges (often mistaken for mosquitoes), no chocolate.

Insects are at the bottom of the food chain - and the base of the pyramid o n which much other life is based.

It is interesting to note that the mosquito, while widespread and perniciou s, is one of the few insects that does not seem to occupy an important plac e in the food chain. Really. And, one of the few that is also immune to mos t conventional attractants. Go figure.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

... which is precisely where they are used.

NT

Reply to
tabbypurr

opulation that are so confused by actual facts that they *MUST* believe the opposite, or they will die.

give them difficulties. A breeze/fan is your best local defense.

prey. Although they prefer warm-blooded prey, they will readily bite reptil es and amphibians should nothing else be available.

This is very old data, it's what the grad student working on his dissertati on on mosquitos told me in college, and that was 1971. So there may be new er info, or he may have been wrong. There is as usual no chance I've remem bered wrong!

But he said mosquitos were not attracted to CO2, but activated by it. CO2 just increased their random flying speed, causing them to be more likely to come into proximity to a warm blooded critter. He also said repellents di dn't repel, but just made it harder for them to find you, so if the density was such they would bump into you anyway you were toast. (that was certai nly true on a camping trip to Canada.)

Reply to
Tim R

tion on mosquitos told me in college, and that was 1971. So there may be n ewer info, or he may have been wrong.

That the data is old does not make it inaccurate. What has changed is how r efined modern mosquito traps operate - which is by a combination of CO2 and heat - just like warm-blooded prey; and how repellents have also been ref ined.

DEET (N,N-Diethyl-meta-toluamide) does, in fact, confuse the mosquito such that it has a hard time landing in order to bite. And in sufficient concent ration (actual contact) it will kill them. But, it and many other oils such as eucalyptus, pennyroyal and similar do have actual repellent properties

- mosquitoes do actually hate the smell. As the non-DEET materials do not c ause confusion, they are poor substitutes in actual practice.

By the way, all the modern traps do is act like a REALLY BIG and attractive lure - and so should be placed some considerable distance, and slightly do wnwind of the area to be protected. Otherwise, they will act as an invitati on to the party.

And, we have Metofluthrin these days, which is a pyrethroid (plant-based) neurotoxin that is a specialized repellent pretty much only for mosquitoes.

Point being that none of this makes bug zappers any more benign.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

tation on mosquitos told me in college, and that was 1971. So there may be newer info, or he may have been wrong.

refined modern mosquito traps operate - which is by a combination of CO2 a nd heat - just like warm-blooded prey; and how repellents have also been r efined.

h that it has a hard time landing in order to bite. And in sufficient conce ntration (actual contact) it will kill them. But, it and many other oils su ch as eucalyptus, pennyroyal and similar do have actual repellent propertie s - mosquitoes do actually hate the smell. As the non-DEET materials do not cause confusion, they are poor substitutes in actual practice.

ve lure - and so should be placed some considerable distance, and slightly downwind of the area to be protected. Otherwise, they will act as an invita tion to the party.

) neurotoxin that is a specialized repellent pretty much only for mosquitoe s.

Using bug zappers outdoors makes about as much sense as having a gas heater outdoors. Even so they could only catch a tiny percentage of the world's i nsects that way.

NT

Reply to
tabbypurr

Actually, they, together with habitat change and such things as lawn services (Chemlawn and such) are threatening entire local ecosystems.

Reply to
peterwieck33

Cat zappers, on the other hand.......................

Reply to
Tim R

True story:

We had a very large, fearless, but gentle Maine Coon named Boswell, who mad e it to age 16, and to 18 pounds before succumbing to cancer. In any case, he was a bit of a wandered, even when neutered. As we had an electronic fe nce for the dogs, we got a collar for him. The first day he wore it, he wal ked up to the edge of the property - we could see him twitch - carefully wa lked through the zap area, turned around and walked back. We went to the fe nce supplier and got the "super max" collar. Next day, he did the same thin g.

Some cats....

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

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