Post by thread:[EE]: Widlar Optimisation.. with a voltage booster

OK, this EPROM refused to program or erase, so I decided to test out my micro-inverter on it. Basically, the uI is a small box built out of bits of a Kodak MAX disposable camera flash. It charges a 120uF capacitor up to 200V and dumps it into the output. The effect on semiconductors is quite spectacular, and usually involves exploding bond wires and flying silicon. Basically, this is my variant on the age-old theme of smashing failed ICs to bits with a very large hammer. Photos: In the middle of the Big Zap: <http://www.philpem.me.uk/bigbang/epromboom.jpg> [ 21 Kbytes ] The micro-inverter (close-up) <http://www.philpem.me.uk/bigbang/inverter.jpg> [ 367 Kbytes ] The EPROM (after blasting) <http://www.philpem.me.uk/bigbang/blastedeprom.jpg> [ 815 Kbytes ] If anyone wants any more info on the "experiment" let me know. I've got CAD files for the inverter PCB (single-sided 0.8mm, based on the "Rev C" Kodak flash with an NPN strobe transistor) if anyone wants to build one. Later. -- Phil. | Acorn RiscPC600 SA220 64MB+6GB 100baseT spam_OUTphilpemTakeThisOuTphilpem.me.uk | Athlon64 3200+ A8VDeluxe R2 512MB+100GB http://www.philpem.me.uk/ | Sony MZ-N710 NetMD Minidisc ... A bird in the hand is safer than one overhead.

Wow! A solid state flash bulb! HH {Quote hidden}> > OK, this EPROM refused to program or erase, so I decided to test out my > micro-inverter on it. Basically, the uI is a small box built out of bits > of > a Kodak MAX disposable camera flash. It charges a 120uF capacitor up to > 200V > and dumps it into the output. The effect on semiconductors is quite > spectacular, and usually involves exploding bond wires and flying silicon. > > Basically, this is my variant on the age-old theme of smashing failed ICs > to > bits with a very large hammer. > > Photos: > In the middle of the Big Zap: > <http://www.philpem.me.uk/bigbang/epromboom.jpg> [ 21 Kbytes ] > The micro-inverter (close-up) > <http://www.philpem.me.uk/bigbang/inverter.jpg> [ 367 Kbytes ] > The EPROM (after blasting) > <http://www.philpem.me.uk/bigbang/blastedeprom.jpg> [ 815 Kbytes ] > > If anyone wants any more info on the "experiment" let me know. I've got > CAD > files for the inverter PCB (single-sided 0.8mm, based on the "Rev C" Kodak > flash with an NPN strobe transistor) if anyone wants to build one. > -- FCC Rules Updated Daily at http://www.hallikainen.com

Mmmm... High voltage destruction! My favorite! I've got a 400V cap lying around. Might give it a shot *grin* Philip Pemberton wrote: {Quote hidden}> OK, this EPROM refused to program or erase, so I decided to test out my > micro-inverter on it. Basically, the uI is a small box built out of bits of > a Kodak MAX disposable camera flash. It charges a 120uF capacitor up to 200V > and dumps it into the output. The effect on semiconductors is quite > spectacular, and usually involves exploding bond wires and flying silicon. > > Basically, this is my variant on the age-old theme of smashing failed ICs to > bits with a very large hammer. > > Photos: > In the middle of the Big Zap: > <http://www.philpem.me.uk/bigbang/epromboom.jpg> [ 21 Kbytes ] > The micro-inverter (close-up) > <http://www.philpem.me.uk/bigbang/inverter.jpg> [ 367 Kbytes ] > The EPROM (after blasting) > <http://www.philpem.me.uk/bigbang/blastedeprom.jpg> [ 815 Kbytes ] > > If anyone wants any more info on the "experiment" let me know. I've got CAD > files for the inverter PCB (single-sided 0.8mm, based on the "Rev C" Kodak > flash with an NPN strobe transistor) if anyone wants to build one. > > Later. -- Hector Martin (.....hectorKILLspam@spam@marcansoft.com) Public Key: http://www.marcansoft.com/hector.asc

In message <.....42F40475.3010202KILLspam.....marcansoft.com> Hector Martin <EraseMEhectorspam_OUTTakeThisOuTmarcansoft.com> wrote: > BTW, why use an inverter at all? Just wire it up to the mains plug > with a fuse and diode and a current-limit resistor. I've seen someone > try that, and it works fine for charging. Well, there's the fact that the 240V UK mains can pump out a serious amount of current - well into the dozens of amps range. The inverter pumps out a few mA and is a hell of a lot safer as a result... Of course, adding the capacitor negates that argument to some degree... Later. -- Phil. | Acorn RiscPC600 SA220 64MB+6GB 100baseT philpemspam_OUTphilpem.me.uk | Athlon64 3200+ A8VDeluxe R2 512MB+100GB http://www.philpem.me.uk/ | Sony MZ-N710 NetMD Minidisc ... I'm not nearly as think as you confused I am.

>> BTW, why use an inverter at all? Just wire it up to the mains >> plug with a fuse and diode and a current-limit resistor. I've >> seen someone try that, and it works fine for charging. > >Well, there's the fact that the 240V UK mains can pump out a >serious amount of current - well into the dozens of amps range. >The inverter pumps out a few mA and is a hell of a lot safer as a result... A lot of people seem to forget that the mains supply is probably about as close as you will ever see, to a perfect voltage source - at least as far as the socket in your house is concerned.

Alan, On Mon, 8 Aug 2005 10:00:52 +0100, Alan B. Pearce wrote: > >Well, there's the fact that the 240V UK mains can pump out a > >serious amount of current - well into the dozens of amps range. > >The inverter pumps out a few mA and is a hell of a lot safer as a result... > > A lot of people seem to forget that the mains supply is probably about as > close as you will ever see, to a perfect voltage source - at least as far as > the socket in your house is concerned. As long as you kept to the wiring regulations when you did your DIY rewire! :-) In the US, where they have less voltage to start with, the wiring seems more prone to lights dimming when you turn on something hefty. At my girlfriend's house in New York, I measured a 7 Volt drop at the dining-room sockets when the microwave is running in the kitchen - this is 7V out of 110V, of course, so quite noticeable. And this is a sustained drop, not just a momentary dip, it carries on until the microwave turns off. Whether this is due to the old (aluminium) wiring or something else, I don't know. Cheers, Howard Winter St.Albans, England

Russell, On Mon, 08 Aug 2005 22:32:12 +1200, Russell McMahon wrote: > > A lot of people seem to forget that the mains supply is probably > > about as > > close as you will ever see, to a perfect voltage source - at least > > as far as > > the socket in your house is concerned. > > It's also an excellent approximation to a perfect current source for > loads below about 0.1 ohm - but not for long :-). Actually it's pretty good up to about an ohm round these parts! :-) It amuses me that the breaking capacity of a 6A Miniature Circuit Breaker (MCB), used for lighting circuits here, is 6kA (yes, six thousand amps). I can't help thinking that the cables it's feeding, usually 1.5mm^2, would be vapour long before the MCB had a chance to trip at that sort of current! Cheers, Howard Winter St.Albans, England

> At my girlfriend's house in New York, I measured a 7 Volt > drop at the dining-room sockets when the microwave is > running in the kitchen Sigh, you're just a plain ole-fashioned romantic aren't you Howard ? A box of chocs, some roses and a Fluke. Do you offer this "service" in restaurants too ;-) A friend of mine is having a battle with one of the Auckland electricity suppliers. His lights (and those in other suburbs he tells me) flicker. The first time I was at his place I thought there was a moth fluttering around the bulb, it's that noticeable. Apparently there's a major consumer causing voltage dips in vast swathes of housing

> In the US, where they have less voltage to start with, the wiring seems >more prone to lights dimming when you > turn on something hefty. Ayup. My office (for various reasons) also happens to be the "break room" (which is to say, the coffee pot, microwave, and full-size refrigerator are in here, and it's the only room where food or drink is officially allowed), and when the compressor in fridge kicks on, I tend to lose RPMs on the drill, temp on the soldering iron or heat gun, and a little light. I'm lobbying for a different office. Mike H.

Mike, On Mon, 8 Aug 2005 09:17:43 -0500, Mike Hord wrote: > > In the US, where they have less voltage to start with, the wiring seems > >more prone to lights dimming when you > > turn on something hefty. > > Ayup. My office (for various reasons) also happens to be the "break room" > (which is to say, the coffee pot, microwave, and full-size refrigerator are in > here, and it's the only room where food or drink is officially allowed), and > when the compressor in fridge kicks on, I tend to lose RPMs on the drill, > temp on the soldering iron or heat gun, and a little light. LOL! What is the allowable voltage drop there? (Installations here are allowed 3% I believe - just under 7V at 230V). > I'm lobbying for a different office. Couldn't you just lobby for a seperate power feed? Cheers, Howard Winter St.Albans, England

{Quote hidden}>-----Original Message----- >From: @spam@piclist-bouncesKILLspammit.edu [KILLspampiclist-bouncesKILLspammit.edu] >Sent: 08 August 2005 15:18 >To: Microcontroller discussion list - Public. >Subject: Re: [EE]: Widlar Optimisation.. with a voltage booster > > >> In the US, where they have less voltage to start with, the wiring >>seems >>more prone to lights dimming when you >> turn on something hefty. > >Ayup. My office (for various reasons) also happens to be the >"break room" (which is to say, the coffee pot, microwave, and >full-size refrigerator are in here, and it's the only room >where food or drink is officially allowed), and when the >compressor in fridge kicks on, I tend to lose RPMs on the >drill, temp on the soldering iron or heat gun, and a little light. > >I'm lobbying for a different office. > >Mike H. Sounds like you have a good case if you are drilling and soldering in a food preparation area! Regards 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. =======================================================================

> > > In the US, where they have less voltage to start with, the wiring seems > > >more prone to lights dimming when you > > > turn on something hefty. > > > > Ayup. My office (for various reasons) also happens to be the "break room" > > (which is to say, the coffee pot, microwave, and full-size refrigerator are in > > here, and it's the only room where food or drink is officially allowed), and > > when the compressor in fridge kicks on, I tend to lose RPMs on the drill, > > temp on the soldering iron or heat gun, and a little light. > > LOL! What is the allowable voltage drop there? (Installations here > are allowed 3% I believe - just under 7V at 230V). Others would know this better than I; I'd be fairly certain I'm exceeding it here. Especially if someone is running the coffee maker and microwave, too! > > I'm lobbying for a different office. > > Couldn't you just lobby for a seperate power feed? I could, but the alternate office is more likely in the near future. It'd give me much needed stretching room, too; my 4 meters of bench space is quite inadequate. Mike H.

> >I'm lobbying for a different office. > > > >Mike H. > > Sounds like you have a good case if you are drilling and > soldering in a food preparation area! Other side of the room. ;-) Actually, though, you are right. For example, when I etch PCBs, which sink do I have to use? These are concerns I have, but basically, there's nothing I can do about them. I just have to clean up after myself, very well, and not do this stuff when people are making food near at hand. Other less-than-foodsafe things go on at that sink, too, since this room is used by many others for many things other than eating. Mike H.

IIRC- NEC/CEC tables show max length of runs for a 5% drop, would assume that the maximum voltage drop recommended. D Mike Hord wrote: >>LOL! What is the allowable voltage drop there? (Installations here >>are allowed 3% I believe - just under 7V at 230V). > Others would know this better than I; I'd be fairly certain I'm exceeding it > here. Especially if someone is running the coffee maker and microwave, > too! > > Mike H.