On Fri, 6 May 2022 16:43:06 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:
John Walliker wrote:
On Friday, 6 May 2022 at 19:44:05 UTC+1, John Larkin wrote:
On Fri, 06 May 2022 17:40:45 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
On Fri, 06 May 2022 17:06:28 +0100, <jla...@highlandsniptechnology.com> wrote:
On Fri, 06 May 2022 13:44:03 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
I\'m talking about the bug zappers. I have a mains one which makes 2000V. I have a USB one which makes 1700V. I can and have measured those. The mains one is very effective, I see it frying wasps. I haven\'t had the opportunity to see the USB one in action yet and I\'m wondering if it will do anything useful. How much current is required to kill the insect? I know 80mA+ is needed to kill a human through the heart, but I get the feeling with insects the death requires evaporation, not just stopping the heart. I could connect a milliammeter across the USB one\'s output, but I don\'t want to break the meter if there\'s a strong pulse to start with. The USB one states 1A 5V input, so the output couldn\'t continuously exceed only 3mA, unless it drops to 100V and gives out 50mA, and the output drops from 1700V to 0V immediately I turn it off (with an antique electrostatic voltmeter connected which may draw a bit).
It\'s energy, from a capacitor, not current that kills bugs.
The cap charging current is likely microamps.
Since when I unplug the USB cord, the voltage drops to 0 instantly, I doubt there\'s a cap in it.
It wouldn\'t be hard to measure. Or google.
The mains one is just a 240V to 2000V transformer directly connected to the rails.
That sounds lethal to bugs and to humans. And a fire hazard.
One outfit that I work with considers 9 joules the be the human
threshold of death. I\'d guess that 1 joule would take out a mosquito.
These devices used to make a loud noise as they discharged a capacitor
into the insect. This is no longer considered a good idea because if the
insect explodes too violently the bacteria-laden fragments are dispersed
over a wide area. It is much better just to cook them without fragmentation.
I did once come across a standard for such devices - I will see if I can find it.
John
Bacteria-laden fragments over a wide area? From a mosquito whose total
mass is a few milligrams?
Sure must be peaceful where you live, if that\'s the biggest worry.
Cheers
Phil Hobbs
Speak for yourself. Where I grew up, the mosquitoes were as big as
chickens.
On Sat, 07 May 2022 00:56:42 +0100, John Larkin <jlarkin@highland_atwork_technology.com> wrote:
On Fri, 6 May 2022 16:43:06 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:
John Walliker wrote:
On Friday, 6 May 2022 at 19:44:05 UTC+1, John Larkin wrote:
On Fri, 06 May 2022 17:40:45 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
On Fri, 06 May 2022 17:06:28 +0100, <jla...@highlandsniptechnology.com> wrote:
On Fri, 06 May 2022 13:44:03 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
I\'m talking about the bug zappers. I have a mains one which makes 2000V. I have a USB one which makes 1700V. I can and have measured those. The mains one is very effective, I see it frying wasps. I haven\'t had the opportunity to see the USB one in action yet and I\'m wondering if it will do anything useful. How much current is required to kill the insect? I know 80mA+ is needed to kill a human through the heart, but I get the feeling with insects the death requires evaporation, not just stopping the heart. I could connect a milliammeter across the USB one\'s output, but I don\'t want to break the meter if there\'s a strong pulse to start with. The USB one states 1A 5V input, so the output couldn\'t continuously exceed only 3mA, unless it drops to 100V and gives out 50mA, and the output drops from 1700V to 0V immediately I turn it off (with an antique electrostatic voltmeter connected which may draw a bit).
It\'s energy, from a capacitor, not current that kills bugs.
The cap charging current is likely microamps.
Since when I unplug the USB cord, the voltage drops to 0 instantly, I doubt there\'s a cap in it.
It wouldn\'t be hard to measure. Or google.
The mains one is just a 240V to 2000V transformer directly connected to the rails.
That sounds lethal to bugs and to humans. And a fire hazard.
One outfit that I work with considers 9 joules the be the human
threshold of death. I\'d guess that 1 joule would take out a mosquito.
These devices used to make a loud noise as they discharged a capacitor
into the insect. This is no longer considered a good idea because if the
insect explodes too violently the bacteria-laden fragments are dispersed
over a wide area. It is much better just to cook them without fragmentation.
I did once come across a standard for such devices - I will see if I can find it.
John
Bacteria-laden fragments over a wide area? From a mosquito whose total
mass is a few milligrams?
Sure must be peaceful where you live, if that\'s the biggest worry.
Cheers
Phil Hobbs
Speak for yourself. Where I grew up, the mosquitoes were as big as
chickens.
I live in Scotland. If you don\'t, you don\'t know what a mosquito is.
On Fri, 6 May 2022 16:43:06 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:
John Walliker wrote:
On Friday, 6 May 2022 at 19:44:05 UTC+1, John Larkin wrote:
On Fri, 06 May 2022 17:40:45 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
On Fri, 06 May 2022 17:06:28 +0100, <jla...@highlandsniptechnology.com> wrote:
On Fri, 06 May 2022 13:44:03 +0100, \"Commander Kinsey\"
C...@nospam.com> wrote:
I\'m talking about the bug zappers. I have a mains one which makes 2000V. I have a USB one which makes 1700V. I can and have measured those. The mains one is very effective, I see it frying wasps. I haven\'t had the opportunity to see the USB one in action yet and I\'m wondering if it will do anything useful. How much current is required to kill the insect? I know 80mA+ is needed to kill a human through the heart, but I get the feeling with insects the death requires evaporation, not just stopping the heart. I could connect a milliammeter across the USB one\'s output, but I don\'t want to break the meter if there\'s a strong pulse to start with. The USB one states 1A 5V input, so the output couldn\'t continuously exceed only 3mA, unless it drops to 100V and gives out 50mA, and the output drops from 1700V to 0V immediately I turn it off (with an antique electrostatic voltmeter connected which may draw a bit).
It\'s energy, from a capacitor, not current that kills bugs.
The cap charging current is likely microamps.
Since when I unplug the USB cord, the voltage drops to 0 instantly, I doubt there\'s a cap in it.
It wouldn\'t be hard to measure. Or google.
The mains one is just a 240V to 2000V transformer directly connected to the rails.
That sounds lethal to bugs and to humans. And a fire hazard.
One outfit that I work with considers 9 joules the be the human
threshold of death. I\'d guess that 1 joule would take out a mosquito.
These devices used to make a loud noise as they discharged a capacitor
into the insect. This is no longer considered a good idea because if the
insect explodes too violently the bacteria-laden fragments are dispersed
over a wide area. It is much better just to cook them without fragmentation.
I did once come across a standard for such devices - I will see if I can find it.
John
Bacteria-laden fragments over a wide area? From a mosquito whose total
mass is a few milligrams?
Sure must be peaceful where you live, if that\'s the biggest worry.
Speak for yourself. Where I grew up, the mosquitoes were as big as
chickens.
On 5/6/2022 10:31 AM, Mike Coon wrote:
In article <op.1lqyzpe3mvhs6z@ryzen.lan>, CK1@nospam.com says...
requires evaporation, not just stopping the heart. I could connect a milliammeter across the USB one\'s output, but I don\'t want to break the meter if there\'s a strong pulse to start with. The USB one states 1A 5V input, so the output couldn\'t continuously exceed only 3mA, unless it drops to 100V and gives out 50mA, and the output drops from 1700V to 0V immediately I turn it off (with an antique electrostatic voltmeter connected which may draw a bit).
Is your electrostatic voltmeter leaky? It should only \"draw\" a charge,
not a current.
BTW I don\'t want my wasps fried, because then the spider to which I
offer them is not interested. They have to wake up and flutter, then she
swoops and bites...
Cool ! What kinda spider you got.
On 5/6/2022 10:31 AM, Mike Coon wrote:
In article <op.1lqyzpe3mvhs6z@ryzen.lan>, CK1@nospam.com says...
requires evaporation, not just stopping the heart. I could connect a
milliammeter across the USB one\'s output, but I don\'t want to break
the meter if there\'s a strong pulse to start with. The USB one states
1A 5V input, so the output couldn\'t continuously exceed only 3mA,
unless it drops to 100V and gives out 50mA, and the output drops from
1700V to 0V immediately I turn it off (with an antique electrostatic
voltmeter connected which may draw a bit).
Is your electrostatic voltmeter leaky? It should only \"draw\" a charge,
not a current.
BTW I don\'t want my wasps fried, because then the spider to which I
offer them is not interested. They have to wake up and flutter, then she
swoops and bites...
Cool ! What kinda spider you got.
On 5/7/2022 2:05 AM, g_wolf wrote:
On 5/6/2022 10:31 AM, Mike Coon wrote:
In article <op.1lqyzpe3mvhs6z@ryzen.lan>, CK1@nospam.com says...
requires evaporation, not just stopping the heart. I could connect a
milliammeter across the USB one\'s output, but I don\'t want to break
the meter if there\'s a strong pulse to start with. The USB one states
1A 5V input, so the output couldn\'t continuously exceed only 3mA,
unless it drops to 100V and gives out 50mA, and the output drops from
1700V to 0V immediately I turn it off (with an antique electrostatic
voltmeter connected which may draw a bit).
Is your electrostatic voltmeter leaky? It should only \"draw\" a charge,
not a current.
BTW I don\'t want my wasps fried, because then the spider to which I
offer them is not interested. They have to wake up and flutter, then she
swoops and bites...
Cool ! What kinda spider you got.
Wolf spider?
In article <2TodK.6666$t72a.1025@fx10.iad>, g_wolf@howl.com says...
On 5/6/2022 10:31 AM, Mike Coon wrote:
In article <op.1lqyzpe3mvhs6z@ryzen.lan>, CK1@nospam.com says...
requires evaporation, not just stopping the heart. I could connect a milliammeter across the USB one\'s output, but I don\'t want to break the meter if there\'s a strong pulse to start with. The USB one states 1A 5V input, so the output couldn\'t continuously exceed only 3mA, unless it drops to 100V and gives out 50mA, and the output drops from 1700V to 0V immediately I turn it off (with an antique electrostatic voltmeter connected which may draw a bit).
Is your electrostatic voltmeter leaky? It should only \"draw\" a charge,
not a current.
BTW I don\'t want my wasps fried, because then the spider to which I
offer them is not interested. They have to wake up and flutter, then she
swoops and bites...
Cool ! What kinda spider you got.
It\'s called a noble false widow
(https://en.wikipedia.org/wiki/Steatoda_nobilis). Not native to the UK
but spreading. When they have egg sacs that hatch into armies of
spiderlings that is when they get hoovered up...