Comments on: Electric roach motel

By: nina

nina — Tue, 29 Mar 2011 08:06:24 +0000

hello. can I ask about the coding for PIC12F683?

By: nina

nina — Sat, 26 Mar 2011 06:29:05 +0000

Do we have to program the PIC..I’m a liltle bit confused.need answer ASAP :)

By: Clint Schirard

Clint Schirard — Fri, 18 Jan 2008 00:09:04 +0000

I built a similar roach motel back in the 1980's. Mine was powered from a 9-volt battery. It used a 555 timer to create a square wave, that was fed into a step-up transformer. I was getting over 200 volts out of the transformer. The output was wired to two copper clad boards, which were laid on the floor so the roaches could then crawl over and complete the circuit through thier bodies..

We saved a lot of money at the grocery store that way.

By: awdark

awdark — Sun, 13 Jan 2008 02:09:16 +0000

That looks so fun. Never tried etching a board before.

In the above comment, someone mentioned using a 555 timer in astable mode, I think 555 timers are easier to find and doesn't need programming. Has anyone developed a more "efficient" version of this device?

Sure seems like something nice to leave in the corners to keep the bugs in check.

By: fentanyl3

fentanyl3 — Sat, 12 Jan 2008 01:44:22 +0000

to really be effective, it needs to use a voltage on the order of thousands of volts. most bug zappers run in the 5 to 15 kilovolt range.

By: Mike

Mike — Fri, 11 Jan 2008 04:09:31 +0000

hmmmmmmmm I wonder if you could use this to keep the dogs from raising their leg in your yard?????

By: Bryon Wright

Bryon Wright — Fri, 11 Jan 2008 01:38:32 +0000

The only failsafe protection is a blow capacitor and a blown diode. No switch?

Also, couldn't you convert this to a micro stungun?

By: will d

will d — Fri, 11 Jan 2008 01:07:20 +0000

i figure an insect’s legs should make excellent physical contact with the surface considering how sticky the feet are. as for how conductive they are, i’d like to know. see if you can get a roach and a multimeter. also, i’d absolutely love to see this thing on youtube.

By: Rangerx52

Rangerx52 — Thu, 10 Jan 2008 18:06:54 +0000

Probably dont need much current to kill a roach. kind of like those electric flyswatters; you can smack your friend with it and make him scream like a little girl, but it wil set a fly on fire if you keep the juice going. I believe those use cheap little transformers for voltage amplification from a 9v battery with constant voltage as opposed to pulsed.

wouldnt really need a body removal system either, the little fellow would just cook until he doesnt conduct anymore (i.e. burnt to a little briquette)

Still love to see it in action.
come one man... trip to the petstore... a feeder pinkie? maybe a handful of crickets?.. a pinkie?

By: RAID

RAID — Thu, 10 Jan 2008 17:41:33 +0000

Why not just make a board with traces like the one above and connect it to 120vac.
Guaranteed crispy critters !

By: Johnny B. Goode

Johnny B. Goode — Thu, 10 Jan 2008 17:41:05 +0000

I think I would probably have to go with some form of a capacitor discharge system. I could yank a couple photo flash caps from some disposable cameras, which would give quite a bit more current that what’s being provided here. Certainly enough to kill a roach I would think, and very possibly mice as well. Hmmmm…

By: SomeBEng

SomeBEng — Thu, 10 Jan 2008 15:02:27 +0000

"In order to consrver power, a zener was used in place of the usual 5 volt regulator. This allows doing extra tricks with the sleep mode for extended battery life."

Er. What would these be? I don't see how a zener diode is a better choice of 5V source than, say a linear regulator (assuming a low quiescent current).

WRT using a 555 - you could but I'd favour the programmability of a PIC. Also the A/D allows the voltage to be measured and it's always handy to have a spare I/O here or there.

By: PKM

PKM — Thu, 10 Jan 2008 13:34:23 +0000

Anyone here read “The Wasp Factory”? All of a sudden I’m reminded of it… :)

By: Rectifier

Rectifier — Thu, 10 Jan 2008 10:11:58 +0000

This sounds like a recipe for a roach on fire - a dead roach will just sit there and smoke, no way to remove it!

This needs an motorized paddle to move across and wipe the dead roach into a bin! True automated killing - you have a few extra lines on that PIC, right? When C1 takes a big voltage hit charring a roach, finish frying it for an extra second or two and then activate the wiper.

@bennyboy: well if it's only stunned and not dead - wipe it into the bin... then activate a crushing device, heh heh heh :D

I was going to build something like this out of an electric swatter to deal with my fruit fly problem - unfortunately a simple trap made out of a bottle and vinegar made short work of them, with no satisfying sparks or loud bangs necessary :(

No cleanup mechanism necessary for fruit flies... they just fall through the mesh.

By: BennyBoy

BennyBoy — Thu, 10 Jan 2008 09:56:17 +0000

I don’t think the electric pulse will be fatal to insects… The “what seems to be” gold trace on the pcb seems to be of enough conductivity to transmit the full 400V pulses to the insect but with it’s carapace, the insect will not absorb enough current to kill, therefore just sort of paralysing it. It’s the same principle as the taser gun; a lot of tension but very very few current passing through the body resulting in a stun/paralyse state instead of death. Current kills, voltage sort of paralyse (to be simpler because on a medical term I don’t think it’s imsple as that).

I’d really like to see proof that this thing actually kill.