bug zapper from hot deals, how does it work?

[unclebabar]

I saw this in the hot deals forum: bug zapper post

It's a bug zapper that works by electrocuting bugs from the current of 2 AA batteries (or ripping them appart from electric potential diffential?). It claims to generate 1500 volts (from 3V?). Anybody know how it works? Is it easy to build such a transformer? Or is the item a bunch of hokey?

zapper link

 

[Krakerjak]

Essentially the transformer needs to have about 500 more turns of wire on the secondary coil as the primary and 1500 volts from 3 volts is possible.

Every vertical wirre in that racket is one of the +ve or -ve ends of that 1500v and the bug just needs to complete the circuit and zap.
They are very painful if you tough it, and in my opinion very unsafe......the button stuck on me once without me knowing and ZAP.

All the circuitry consists of is a transformer, some resistors, a fat ass capacitor, a diode, and a regulator.
If you know what you are doing it couldnt be too hard to make at all.

 

[Bozz]

You cannot get more energy out than you put in.

You can increase voltage or current but it will inversely affect the other.

In a perfect world, if you double the voltage, the current will halve and vice versa. This will not happen in a perfect world due to electrical losses etc...

At 1500 volts, you'd have a very small amount of current to harm anything unless it is charged and stored and occasionally discharged....

 

[Santte]

Ah. The sweet smell of burning mosquito
We have had one for couple of years. Very handy for killing the insect flying close to the wall,
no need to worry about leaving a mark.

Would be very easy to make yourself, but for 5 dollars it would be a waste of time.

BTW. It isn't powerfull enough to kill larger insects than small flies and mosquitos, it only stuns
them. Also some of the insect explode on contact and make a nice popping sound...

 

[arcas]

On a similar note, I'm curious how traditional hanging bug zappers actually work. I'm well aware of how they use a step-up transformer to boost the voltage but I'm curious how the grid actually zaps tiny bugs. I'll explain:

I have two hang-type bug zappers stored away that haven't been used in years. One has two presumably oppositely charged cylindrical metal grids such that one cylinder is roughly 1/4 or 1/2 inch inside the other. The other has a ring of rods again spaced maybe 1/2 inch apart with adjacent rods presumably oppositely charged. So the potential on one of the mesh grids or on one of the rods is say +/-2000V. Now, let's say a gnat flies in. How does it get zapped? The gnat is obviously nowhere near large enough to bridge the gap so the circuit isn't closed.

Am I correct in assuming the bug is "zapped" from the sudden increase of potential when it comes sufficiently close to the grid...going from essentially neutral to say -2000V? So that it's similar to the shock you receive from bringing your hand close to a Van de Graff generator even though you're well insulated from ground?

 

[sxr7171]

I got zapped before by the innards of a camera flash unit. It won't kill you (obviously) but it isn't pleasant either. There's just too little current to kill anyone.

 

[unclebabar]

> Am I correct in assuming the bug is "zapped" from the sudden increase of potential when it comes sufficiently close to the grid...going from essentially neutral to say -2000V? So that it's similar to the shock you receive from bringing your hand close to a Van de Graff generator even though you're well insulated from ground?

my guess is that the the gnat doesn't need to touch the oppositely charged pole (if there is one). Just touching a live wire in two places will make it part of the circuit. with 6? legs and two wings, it doesn't look good for the gnat.

I've read that even milliamps are enough to kill some one (of course the voltage has to be high enough to drive the current through you).

 

[Aquinas]

yeah! I too took a camera apart and got the zap! I was only 12 at the time, and I thought I was going to die...electricity is fun! If only I could find a way to zap my neighbor's dog...

 

[Shinj1EVA]

Originally posted by: sxr7171
I got zapped before by the innards of a camera flash unit. It won't kill you (obviously) but it isn't pleasant either. There's just too little current to kill anyone.

You kno, touching the innards of a PSU while it's still plugged in is quite a pleasant experience.. no not really, i'm lying. My hand was numb for a couple of minutes. :/

 

[sxr7171]

I was actually thinking that some of these devices could have a market as safe pain/pleasure toys. But, I'm sure someone else is already selling stuff like this for the purpose. I remember touching a 240v line once, and it hurt for a second, but it was kind of cool when your hand goes numb.

 

[unclebabar]

if was a 30 amp line, it's a miracle you're not dead.

 

[gritz]

nevermind

 

[jwo7777777]

Bug Zappers:

UV light in middle with 2 cylindrical metal grids surrounding.

The kill zone is between the two grids. The trick to design is to control the voltage and the inter-grid spacing so that a bug in between the grids will provide an electrical path of low enough resistance while humid air will not. Remember: air and water are conductors of electricity, its just that dry air really sucks at it. So does perfectly pure water....but that's for another thread.

There are of course multitudes of variations on the idea but the basics are described above.