Post by thread:[PIC]: Anyone tried running a PIC with RF-energy ?

After I stumbled across some of the old RF-powered circuitry and radio info, I just had to play a little... I set up a 3-4 meter wire around a room, and connected another wire to ground. Then I made myself a little 4-way rectifier with 4 small-signal diodes. I connected the outputs to a capacitor and the inputs to the two wires. Later I found out I needed something to connect to the capacitor, and decided on a push-button and a led with series resistor. After soldering wires to the cap in one end, i took a bite of the other end to get the insulation off. I got a bit baffled because it really hurt!!! I got shocked! Pulling out my trusted DVM I measured 78 volts across the capacitor. No wonder it hurt! So, now the fun begun. I could wair 30 secos to a minute, then push the button and the led would blink. Again and again... This kept me happy four about half an hour :-))) I know the theory and such behind this, but I was wondering if someone has made something useful with such a contraption? Like powering a pic and a temp-logger in some far away place and then go back to it and collect it to look at the readings... It could be left alone for very long because it would get power from a solid-state solution. Oh'well. I'm going to the attic to rummage in my junk-pile. I think I have some old "glimm-lights" or whatever they are called. Those that look like two drumsticks in a glass bulb. You put enough current on them and they suddently light up like a fluorecent tube. If you don't have a series resistor on them they can really go off with a bang... Maby I can even get my cold cathode to light up or blink with this ??? We all need to play a bit once in a while, between playing! KreAture -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Cool experiment! Not to poke holes in your ideas...but won't putting an RF powered device far away from everything reduce its power input greatly? I don't really know what frequencies your device is picking up on, but my understanding is that alot of the RF in the air is a byproduct of AC power...which there may not be much of in the middle of a field somewhere :) Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams Kyrre Aalerud wrote: > I know the theory and such behind this, but I was wondering if someone has > made something useful with such a contraption? Like powering a pic and a > temp-logger in some far away place and then go back to it and collect it to > look at the readings... It could be left alone for very long because it > would get power from a solid-state solution. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

> I set up a 3-4 meter wire around a room, and connected another wire to > ground. > Then I made myself a little 4-way rectifier with 4 small-signal diodes. I > connected the outputs to a capacitor and the inputs to the two wires. > > Later I found out I needed something to connect to the capacitor, and > decided on a push-button and a led with series resistor. After soldering > wires to the cap in one end, i took a bite of the other end to get the > insulation off. I got a bit baffled because it really hurt!!! I got > shocked! Pulling out my trusted DVM I measured 78 volts across the > capacitor. No wonder it hurt! This doesn't sound right. I bet you were capacitively picking up power line noise from your house, not RF unless you happen to be next door to a transmitter. 78V sounds way out of line for raw voltage from an antenna without even a resonant circuit. I used to have a crystal radio connected to a 20 meter antenna. The strongest station was 50KW at 1.03MHz about 20 miles away. This of course did have a resonant circuit, and the open circuit output was a few volts. The power was sufficient to drive a pair of headphones (the old fashioned high impedence kind) to reasonable volume. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam.....mitvma.mit.edu>

> Power was about 227 nW, Thats nano-watts!!! > I let the power build up in a capacitor before i took a bite at it with my > lips. > This would hurt even with only 12 volts... I wasn't talking about the power, but rather the voltage, although 227nW is also a lot to believe for normal RF. It still doesn't seem right to me that you get 78V from a short wire without a resonant circuit. I therefore think you either live next door to a radio transmitter (hopefully you would have mentioned this), or more likely are capacitively coupled to the power line in your house. Take this same wire in the middle of the back yard away from power lines and see what you get. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspam_OUTTakeThisOuTmitvma.mit.edu>

Something to do with your earth ground? ----- Original Message ----- From: "Kyrre Aalerud" <kreaturespam_OUTC2I.NET> > But, the antenna is directional and placed on the roof. I'm in the > basement. > > I've now replaced the bridge btw with another just to test. > This one gives me about 22 volts across my 4.7uF 63v capacitor. > > Testing something... Yup! It still hurts! -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-requestKILLspammitvma.mit.edu>

Kyrre Aalerud wrote: > > Power was about 227 nW, Thats nano-watts!!! Plenty enough to run a PIC, with a small enough duty cycle of course. Now try a *larger* antenna tuned to one of the sun's peak RF frequencies, and you might qualify for the first Piclist "perpetuum mobile prize" (TM). But don't be surprised if the trophy is a rubber dog poo. <grin> -Roman -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestKILLspammitvma.mit.edu>

Lol, I'm in the race! KreAture ----- Original Message ----- From: "Roman Black" <RemoveMEfastvidTakeThisOuTEZY.NET.AU> To: <spamBeGonePICLISTspamBeGoneMITVMA.MIT.EDU> Sent: Tuesday, January 21, 2003 5:20 PM Subject: Re: [PIC]: Anyone tried running a PIC with RF-energy ? {Quote hidden}> Kyrre Aalerud wrote: > > > > Power was about 227 nW, Thats nano-watts!!! > > > Plenty enough to run a PIC, with a small enough duty > cycle of course. > > Now try a *larger* antenna tuned to one of the sun's > peak RF frequencies, and you might qualify for the > first Piclist "perpetuum mobile prize" (TM). But > don't be surprised if the trophy is a rubber dog poo. > <grin> > -Roman > > -- > http://www.piclist.com hint: To leave the PICList > TakeThisOuTpiclist-unsubscribe-requestEraseMEspam_OUTmitvma.mit.edu > -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu>

According to PIC16F628 datasheet, it will need 15uA at 3 volts with 32 kHz clock. This gives me an apparent resistance of 200 kOhm. So all I need to do is get 45 uW out of the air, at a load of 200 kOhm. It should limit itself as increased viltage will mean increased power consumption... (To a certain degree... Better add a 5.1 zener to limit max voltage...) Weeeee, this is much more fun than doing a data-capture device :-) KreAture -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestEraseME.....mitvma.mit.edu>

On Tue, 21 Jan 2003, Kyrre Aalerud wrote: *>Hmm, well, I connect gnd to a copper pipe in my bathroom as I don't have *>grounding in the computer/hobby-room. The fact that I have 3 computers here *>running without proper grounding may be a very good explenation :-) Know what, we enjoy your postings, so your first project starting NOW is to find out how you can get those computers grounded properly before they set something on fire or make you ready for a Darwin award. Of course they run also when you sleep, no ? Peter -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestmitvma.mit.edu>

On Wed, 22 Jan 2003, Roman Black wrote: *>Kyrre Aalerud wrote: *>> *>> Power was about 227 nW, Thats nano-watts!!! *> *> *>Plenty enough to run a PIC, with a small enough duty *>cycle of course. Yeah, assuming you only need 1 second of pic operation every 17 minutes or so. Peter -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestEraseMEEraseMEmitvma.mit.edu>

On Tue, 21 Jan 2003, Kyrre Aalerud wrote: *>Yes they do run while I sleep, and I sleep in the same room. *>I wish for grounding in this room, but it's expensive to alter existing *>installments. FYI a perfectly grounded computer once tried to kill me by asphyxiation. A filter cap in the ripple pi filter of the psu went and the fans blew all the smoke in my face. I was in a small room with lots of equipment and I was about halfway through my life memories by the time I fell through the door and 3/4 through them by the time I stopped coughing. Normal eyesight returned later (I had to grope my way out blindly between working energised equipment with all the covers off etc). The fans filled the room so fast you could not see the smoke except when looking from the outside (it came in a cloud out of the door and later window). And I was not sleeping when it happened. The failed cap was a 'blue' X2 cap about 1" x 0.3" x 0.75". Peter -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestspam_OUTKILLspammitvma.mit.edu>

> On Tue, 21 Jan 2003, Kyrre Aalerud wrote: > > *>Yes they do run while I sleep, and I sleep in the same room. > *>I wish for grounding in this room, but it's expensive to alter existing > *>installments. > > FYI a perfectly grounded computer once tried to kill me by asphyxiation. A > filter cap in the ripple pi filter of the psu went and the fans blew all During my college days I built my first computer: a 6502 with (eventually) 18k RAM and a 100k 8" floppy drive. Unfortunately my power-supply design skills, to put it bluntly, sucked. I used the largest cap I could get: a *large* electrolytic (about twice the dimensions of a 12oz soda can). One evening the sucker exploded. The *entire* house heard it, and my roommate was afraid to come anywhere near my computer ever again. I couldn't hear right for a week. On the positive side, the wooden case I built for it contained the damage, and with the help of a friend who was good at power supplies, the computer was running again in a few days! -- D. Jay Newman ! I can bring whole cities to ruin, RemoveMEjayTakeThisOuTspamsprucegrove.com ! And still have time to get a soft-shoe in... http://enerd.ws/ ! -- from Buffy, "Once More with Feeling" -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu>

Now we know why the security product "Smoke Cloak" is so effective. UNfortunately it uses harmless theatrical smoke (glycol) rather than something that would be toxic to the thieves. I'll have to figure out a way to make capacitors fail on cue.... R "Peter L. Peres" wrote: {Quote hidden}> > On Tue, 21 Jan 2003, Kyrre Aalerud wrote: > > *>Yes they do run while I sleep, and I sleep in the same room. > *>I wish for grounding in this room, but it's expensive to alter existing > *>installments. > > FYI a perfectly grounded computer once tried to kill me by asphyxiation. A > filter cap in the ripple pi filter of the psu went and the fans blew all > the smoke in my face. I was in a small room with lots of equipment and I > was about halfway through my life memories by the time I fell through the > door and 3/4 through them by the time I stopped coughing. Normal eyesight > returned later (I had to grope my way out blindly between working > energised equipment with all the covers off etc). The fans filled the room > so fast you could not see the smoke except when looking from the outside > (it came in a cloud out of the door and later window). And I was not > sleeping when it happened. The failed cap was a 'blue' X2 cap about 1" x > 0.3" x 0.75". > > Peter > > -- > http://www.piclist.com hint: To leave the PICList > RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu>

On Tue, 21 Jan 2003, Robert Rolf wrote: *>Now we know why the security product "Smoke Cloak" is so effective. *>UNfortunately it uses harmless theatrical smoke (glycol) rather than *>something that would be toxic to the thieves. *> *>I'll have to figure out a way to make capacitors fail on cue.... Uh, I think there are several specialists on this on the list ... Peter -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu>

Peter L. Peres wrote: > *>Now we know why the security product "Smoke Cloak" is so effective. > *>UNfortunately it uses harmless theatrical smoke (glycol) rather than > *>something that would be toxic to the thieves. > *> > *>I'll have to figure out a way to make capacitors fail on cue.... > > Uh, I think there are several specialists on this on the list ... Back when we were children my brother and I would connect a low-voltage electrolytic capacitor to the output of a model train variable transformer. Then we'd take turns increasing the control dial, and whoever managed to increase the dial the last before the capacitor blew would be the winner. Talk about kids with time on their hands... -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestspamBeGonemitvma.mit.edu>

Well now, for those of us that have disabled all topics but [PIC]: just to get *only* PIC related, technical, quality stuff, could this be moved someware else ?? Maka it [OT]:, [EE]:, [look-how-many-silly-posts-I-can-do-in-24h!]: or whatever... Jan-Erik Svderholm S:t Anna Data -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestEraseMEmitvma.mit.edu>

> Back when we were children my brother and I would connect a low-voltage > electrolytic capacitor to the output of a model train variable > transformer. Then we'd take turns increasing the control dial, and > whoever managed to increase the dial the last before the capacitor blew > would be the winner. > > Talk about kids with time on their hands... And capacitors. When I was a kid big capacitors were too precious to blow up. I needed all I could to take the ripple out of power supplies. This was before I discovered regulated supplies. A power supply was four or more of those gray selenium plates stuck together, followed by as many capacitors as you could get your hands on. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-request@spam@spam_OUTmitvma.mit.edu>

More fun with caps: Get a big one (radial), bend the leads so almost touch, charge it up, and toss it to your soon-to-be-ex friend. ;) Andy At 09:50 PM 1/21/03 +0100, you wrote: >Simple. Use electrolytic caps and give them about same voltage as their >rating, but reverse the polarity. >(Oh, and stand back!) > >We did this all the time back in school. > > KreAture > >{Original Message removed}

>And capacitors. When I was a kid big capacitors were too precious to blow >up. I needed all I could to take the ripple out of power supplies. This "Back when I was a young engineer" we used to insert 2716's into the burners backwards and watch them glow. Usually it took a while - 10-15 seconds - before the lights went out. And that was $5 a pop in 1970's/80's money. Now you can't even see them glow most of the time because they replaced the windowed chips with flash. (I _did_ manage to accomplish this with a PIC18F6720 the other day. My scope probe slipped and connected Vpp to an adjacent pin). Andy -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestKILLspammitvma.mit.edu>

> -----Original Message----- > From: Roman Black [SMTP:.....fastvidspam_OUTEZY.NET.AU] > Sent: Tuesday, January 21, 2003 4:21 PM > To: TakeThisOuTPICLIST.....TakeThisOuTMITVMA.MIT.EDU > Subject: Re: [PIC]: Anyone tried running a PIC with RF-energy ? > > Now try a *larger* antenna tuned to one of the sun's > peak RF frequencies, and you might qualify for the > first Piclist "perpetuum mobile prize" (TM). But > don't be surprised if the trophy is a rubber dog poo. > <grin> > -Roman > I'm sure we can do better than that, a mere imitation hardly seems reward enough :o) Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= Any questions about Bookham's E-Mail service should be directed to TakeThisOuTpostmasterKILLspamspambookham.com. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Tue, 21 Jan 2003, Andy Kunz wrote: *>Now you can't even see them glow most of the time because they replaced the *>windowed chips with flash. (I _did_ manage to accomplish this with a *>PIC18F6720 the other day. My scope probe slipped and connected Vpp to an *>adjacent pin). Vpp is supposed to be current limited to ~40mA, no ? <duck> I almost managed to light up a 16C54W way back when I designed my first programmer from scratch but I stopped just in time. That last extra check is worth it ;-) Peter -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics