I've got a real number of a BAD DIY project to post here!
Anyone ever tried to make a class A amp using nothing but 32 2N3055's??? I have!!!!!
Here's how it started. I worked at a radio shop repairing audio and radio equipment and found this enourmous, and I mean ENORMOUS heatsink with 32 3055's mounted on it. The heatsink was 4 1/2 feet long, 3/4 feet wide and 1/2 feet deep. It weighed about 50lbs!
Anyway, I just HAD to have it!!!! I asked the boss nicely and he said yes, boy oh boy what a find! JACKPOT
Apparently this monster was a power regulator output block from the hydro company, they upgraded to some sort of new topology that dissipated less heat and took up far less room.
I took this puppy home that night and gave it a close look at.
30 of the transistors were in parallel with .5ohm emitter resistors and common base and collectors. Those 30 were driven in darlington by the first 2 which were in parallel with eachother.
I figured, how hard could it be??? I took the primary coil off a microwave transformer and used it as the collector load and hooked the puppy up to a 5kva 80V DC power supply I had kicking around with the emitters to ground and the collectors to positive through the primary of the mic trannie (without the core attached). I then made a simple resistive divider to bias the thing out of some monster 35watt resistors and hooked that up to the PSU as well. I connected a 300watt sub to the collectors through a cap and connected the bases through a cap to my Fisher 80-C tube preamp. Now for the fireworks show! I engaged the supply, which drew about 12 amps idle from the outlet with that monster load. I put some audio through the sucker and man oh man, it actually worked! Had some kick too. When I cranked it, the load resistor made of tranny winding would vibrate violently, causing any metal objects within close proximity to sympathetically do the same! That puppy would draw about 20amps from the PSU at full tilt. The huge heatsink nicely heated the room it was in!
SO... has anybody ever done something as crazy as this????
Anyone ever tried to make a class A amp using nothing but 32 2N3055's??? I have!!!!!
Here's how it started. I worked at a radio shop repairing audio and radio equipment and found this enourmous, and I mean ENORMOUS heatsink with 32 3055's mounted on it. The heatsink was 4 1/2 feet long, 3/4 feet wide and 1/2 feet deep. It weighed about 50lbs!
Anyway, I just HAD to have it!!!! I asked the boss nicely and he said yes, boy oh boy what a find! JACKPOT
Apparently this monster was a power regulator output block from the hydro company, they upgraded to some sort of new topology that dissipated less heat and took up far less room.I took this puppy home that night and gave it a close look at.
30 of the transistors were in parallel with .5ohm emitter resistors and common base and collectors. Those 30 were driven in darlington by the first 2 which were in parallel with eachother.
I figured, how hard could it be??? I took the primary coil off a microwave transformer and used it as the collector load and hooked the puppy up to a 5kva 80V DC power supply I had kicking around with the emitters to ground and the collectors to positive through the primary of the mic trannie (without the core attached). I then made a simple resistive divider to bias the thing out of some monster 35watt resistors and hooked that up to the PSU as well. I connected a 300watt sub to the collectors through a cap and connected the bases through a cap to my Fisher 80-C tube preamp. Now for the fireworks show! I engaged the supply, which drew about 12 amps idle from the outlet with that monster load. I put some audio through the sucker and man oh man, it actually worked! Had some kick too. When I cranked it, the load resistor made of tranny winding would vibrate violently, causing any metal objects within close proximity to sympathetically do the same! That puppy would draw about 20amps from the PSU at full tilt. The huge heatsink nicely heated the room it was in!
SO... has anybody ever done something as crazy as this????
Kilowatt said:
Pulsed power is neat stuff! I see on the net that there are some people playing with 45kJ... ...very impressive. The only probelm is that at energies like that death comes easy. I've got a 450V 15000uF cap, which I am deathly afraid of at full charge...
I play with pulsed power a little. Usually in the form of a carefully wound solenoid, small hardened steel finishing nail, and cap bank with triggered spark gap. Try to explain to your wife that the flying object bouncing around the room is really a harmless science experiment. (At around 100fps, a nail will bounce on two walls before hitting the floor!)
I've often thought of combining the method of triggeing lightning and quarter shrinking... ...that would fit well here...
I'm sure you could shrink more than a quarter. Maybe a car?
The capacitors I play with are 51uF (measured) 15kV. I actually have 6, but I only have the bussbars to hook up 3 together. For my big lateral disc gun (an EM weapon that shoots a sharpened 4" x 1/32" aluminum disc edgewise from between two flat coils; I made a 1 3/4" prototype, it worked quite well
), I will use all 6 (3 for each stage) charged all the way up, which is 34kJ. The caps aren't high quality ones though, I'm sure some day they will blow up even though I try to go easy on them. I got them at Golden Recycling for $25 apiece. I believe they were once filter caps for a large DC power supply of some kind (maybe a radio transmitter?), because they are rated in V DC, not AC. Hey, what speaker is that? Is it a Vifa or something?
the driver is the best
Focal 5 1/4" is upgraded & replaced by later models
see also JMLab Utopia
JMLab Focal - Utopia
Focal 5 1/4" is upgraded & replaced by later models
see also JMLab Utopia
JMLab Focal - Utopia
Thing learned or maybe not learned from my youth:
1. Never try to repair a power extension cord while the other end is still plugged to the power outlet...
2. Never try to repair a power extension chord which has been properly disconnected (see 1.) while another kid is playing near (I was seven years old). He thought it funny to simply plug it back into the wall...
3. Never try to elecrocute your teddybear with your blowdryer in your bathtub, your mum probably won't like it (and it will lead you to listening to death metal)
4. (not electrical) Never lay a new carpet made out of "loops", and drill holes through it (for the mounting of the brass-bar in the door) . If you do, see if you can get more than about 20 meters of wool on your drill (that was five times the length of my room)
5. Never shortconnect a BIG (1 F) Capacitor for car-mounting (especially if it has no protection-circuit). But if you do, close the trunk quickly, and watch some nice bumbs appear in the metal of the trunk while the cap blows up ... And probably you will lose your screwdriver, which could be welded to the poles of the cap... and get a cleaning fluid for electrolytics...
Boy, I wish I could say I have learned, but the stupidity book just keeps on filling... (But now the victims are getting more expensive...
)...
Ciao,
Arndt
1. Never try to repair a power extension cord while the other end is still plugged to the power outlet...
2. Never try to repair a power extension chord which has been properly disconnected (see 1.) while another kid is playing near (I was seven years old). He thought it funny to simply plug it back into the wall...
3. Never try to elecrocute your teddybear with your blowdryer in your bathtub, your mum probably won't like it (and it will lead you to listening to death metal)
4. (not electrical) Never lay a new carpet made out of "loops", and drill holes through it (for the mounting of the brass-bar in the door)
. If you do, see if you can get more than about 20 meters of wool on your drill (that was five times the length of my room)5. Never shortconnect a BIG (1 F) Capacitor for car-mounting (especially if it has no protection-circuit). But if you do, close the trunk quickly, and watch some nice bumbs appear in the metal of the trunk while the cap blows up
... And probably you will lose your screwdriver, which could be welded to the poles of the cap... and get a cleaning fluid for electrolytics...Boy, I wish I could say I have learned, but the stupidity book just keeps on filling... (But now the victims are getting more expensive...
)...Ciao,
Arndt
were do i start,at 8 i wired some mains lamps up and had the idea that if i fed the mains into the end of the circuit they would get brighter as the voltage would be double,guess i got thhe live and neutral crossed over somewear. At 12 i was making my swear box,4 7 segment led diplays,multipole switch and lots of interconecting,being the usual male teen my workshop=bedroom=mess so i was working on the floor,went to stand up, put my hand down to push myself up and realised it was time to get a soldering iron stand.
later in life i was load testing a 500kva ups prior to wiring in the outgoing feeds ,brought the load up slowly got to about 200kva when it triped out,mmm unusual ,decided it was tea break and went for a coffee,5 minutes later im being paged,rung the office ,the company im working for have lost all power to the computer suite could i have a look.woops the ups was wired to the same incoming supply as the ups,the idea being to transfer the computer suite onto the ups once commisioned
lastest was getting 300 volts across the ouput of an opamp,made a good smoke machine though
At collage hours of fun was had with a mains plug and a switch wired between neutral and earth,evertime the lecture touched the screen we'd flick the switch ,solder in light fittings was another one to confuse the caretaker
later in life i was load testing a 500kva ups prior to wiring in the outgoing feeds ,brought the load up slowly got to about 200kva when it triped out,mmm unusual ,decided it was tea break and went for a coffee,5 minutes later im being paged,rung the office ,the company im working for have lost all power to the computer suite could i have a look.woops the ups was wired to the same incoming supply as the ups,the idea being to transfer the computer suite onto the ups once commisioned
lastest was getting 300 volts across the ouput of an opamp,made a good smoke machine though
At collage hours of fun was had with a mains plug and a switch wired between neutral and earth,evertime the lecture touched the screen we'd flick the switch
,solder in light fittings was another one to confuse the caretaker
LOL @ the funny stories here!!!!
I moved into a disused factory in Melbourne, Australia with some other guys, it was really cheap rent but we had no walls, hot water or anything... So we built all the interior walls over summer (did a nice job too!) and it was quite a groovy place, apart from the cold showers.
We got a used hot water cylinder eventually, but due to the complex wiring in the factory, we weren't sure where it should conntect, and temporarily we just connected it to a normal outlet! The extension cord we used got a bit hot, but all the wiring in the factory was industrial grade, so we figured it would handle it for a few months at least.
However, unknown to us it was on the same circuit as the kitchen, and one cold morning about a month later there was a jug, toaster, heater and hot water cylinder all connected on the same 10A fuse (uprated from a 6A)... The fuseboard basically exploded, there were flames and evil smelling smoke everywhere! We had to pay an electrician several hundred to fix that one
I moved into a disused factory in Melbourne, Australia with some other guys, it was really cheap rent but we had no walls, hot water or anything... So we built all the interior walls over summer (did a nice job too!) and it was quite a groovy place, apart from the cold showers.
We got a used hot water cylinder eventually, but due to the complex wiring in the factory, we weren't sure where it should conntect, and temporarily we just connected it to a normal outlet! The extension cord we used got a bit hot, but all the wiring in the factory was industrial grade, so we figured it would handle it for a few months at least.
However, unknown to us it was on the same circuit as the kitchen, and one cold morning about a month later there was a jug, toaster, heater and hot water cylinder all connected on the same 10A fuse (uprated from a 6A)... The fuseboard basically exploded, there were flames and evil smelling smoke everywhere! We had to pay an electrician several hundred to fix that one
Happened to me when I was 14 or so...
I was drilling holes using a drill press and I had to change tools often.
As usual, placed my piece on the table, started the thing, let her to spin up to 1500-2000 rpm and bang ! A bullet passed several inches of my head and finished its course somewhere in the back of the room.
Actually, I forgot once to remove the "key" used to tighten or loose the chuck holding the bit.
Now, I take care to tie those things with a wide leather strip just in case.... and I always wear safety glasses !
I was drilling holes using a drill press and I had to change tools often.
As usual, placed my piece on the table, started the thing, let her to spin up to 1500-2000 rpm and bang ! A bullet passed several inches of my head and finished its course somewhere in the back of the room.
Actually, I forgot once to remove the "key" used to tighten or loose the chuck holding the bit.
Now, I take care to tie those things with a wide leather strip just in case.... and I always wear safety glasses !
When i was 13 I built a device that disproved the existence of God with nothing but a pickle and a piece of string. I didn't think a whole lot of it at the time as i had moved onto building a lego castle with a neat little stable for the horses to live in. Well, the local paper did a little blurb about it in the 'Tuesdays Newsdays' column where they detail people from the community who are selling potholders made out of recycled newsprint or whatever....
From there word moved quickly to the TV televangelist community who blew it completely out of proportion. They sensed this could put a ding in their call in donations and perhaps make them late on their yacht payments, so they sent a bunch of thugs to my house. They roughed up my father until i told them i would never release my findings to the general public under fear of prosecution and possible jail time.
Fast forward to last summer when i leaked the blueprints to the Chinese mafia in exchange for a crateload of fireworks for fourth of July. I mean, these were KILLER fireworks....spelled out my name in the sky and stuff. Anyways, 3 days later I get an 8x10" photo in my mail that shows my father hooked up to a car battery and missing at least 3 fingers ( the photo was taken in bad lighting). It had been 12 years since the original incident...and they had never mentioned torture!!!
Long story short i had to track down the members of the chinese mafia whom i sold the blueprints to, and pay a private militia to 'take care' of them. Once i had physical proof to show the televangelists that all who had seen the blueprints plus all their family members had been terminated, they released my father back into my custody.
A year of psychological evaluation and 3 prosthetic fingers later, and my father is back to his old self again....with the exception that he cant change the TV channel with the remote control because his prosthetic fingers dont bend right. So i gotta drive all the way over to his house to change the channel for him when he wants to watch golf.
That's why it was the worst DIY project ever.
-Maz
From there word moved quickly to the TV televangelist community who blew it completely out of proportion. They sensed this could put a ding in their call in donations and perhaps make them late on their yacht payments, so they sent a bunch of thugs to my house. They roughed up my father until i told them i would never release my findings to the general public under fear of prosecution and possible jail time.
Fast forward to last summer when i leaked the blueprints to the Chinese mafia in exchange for a crateload of fireworks for fourth of July. I mean, these were KILLER fireworks....spelled out my name in the sky and stuff. Anyways, 3 days later I get an 8x10" photo in my mail that shows my father hooked up to a car battery and missing at least 3 fingers ( the photo was taken in bad lighting). It had been 12 years since the original incident...and they had never mentioned torture!!!
Long story short i had to track down the members of the chinese mafia whom i sold the blueprints to, and pay a private militia to 'take care' of them. Once i had physical proof to show the televangelists that all who had seen the blueprints plus all their family members had been terminated, they released my father back into my custody.
A year of psychological evaluation and 3 prosthetic fingers later, and my father is back to his old self again....with the exception that he cant change the TV channel with the remote control because his prosthetic fingers dont bend right. So i gotta drive all the way over to his house to change the channel for him when he wants to watch golf.
That's why it was the worst DIY project ever.
-Maz
Oooooooops !
Just a few oops’s I can remember (and willing to admit to) :-
[1] Building a 0-24V stabilized power supply and packaging it in a wooden box (resplendent with dovetail joints – OK I was only 13). While demonstrating said device the recycled supply cap decided to part company with it’s alloy can and, in the process, reduced the box to matchwood. Strangely, the PSU was still working
[2] Powering up a big lighting rig while a (stupid) colleague was stripping wires with his teeth (as you do). I guess he only got the leakage current through the SCR’s but as he jumped up he knocked himself out on a piece of the set
[3] Having some fancy shaped PCB’s manufactured at great expense (while working for a major nationalised industry in the UK – definitely no names !) – when I got them back I quickly realised the top and bottom tracks had been transposed. I still managed to make the prototypes by bending the pins back to front on some 8 pin DIL packages
DRC
Just a few oops’s I can remember (and willing to admit to) :-
[1] Building a 0-24V stabilized power supply and packaging it in a wooden box (resplendent with dovetail joints – OK I was only 13). While demonstrating said device the recycled supply cap decided to part company with it’s alloy can and, in the process, reduced the box to matchwood. Strangely, the PSU was still working
[2] Powering up a big lighting rig while a (stupid) colleague was stripping wires with his teeth (as you do). I guess he only got the leakage current through the SCR’s but as he jumped up he knocked himself out on a piece of the set
[3] Having some fancy shaped PCB’s manufactured at great expense (while working for a major nationalised industry in the UK – definitely no names !) – when I got them back I quickly realised the top and bottom tracks had been transposed. I still managed to make the prototypes by bending the pins back to front on some 8 pin DIL packages
DRC
When I was about 11 years old, I tried arc welding off the line using a 55 gal barrel of water as a current limiting resistor. To get enough current I lugged on at the service entrance busses.
Much steam and boiling water.... and a rather poor weld with lots of flux inclusions.
Only had dc rod, maybe thats where I went wrong?
Cyclotronguy
Much steam and boiling water.... and a rather poor weld with lots of flux inclusions.
Only had dc rod, maybe thats where I went wrong?
Cyclotronguy
The most dangerous things i've done
1. opened a big 30 inch,but old colour tv,whilst still on,and shorted the main capacitors with a screwdriver with thick insulation.The capacitors were rated 650v 33000uf,and after shorting them they were just a huge blob of awful acrid smelling plastic,as well as the screwdriver handle which melted extremely fast,luckerly i dropped it before it electrocuted me.
2. Dropped a tv down 4 flights of stairs,with the back off,and switched on,and attached to an extension lead.
The tube broke,and glass flew everywhere,as well as a loud hiss of the pressure.And then it pulled the socket from the wall,and shorted the contacts,as well as seeing a big 50cm length flash.
3.Threw metal poles,from a bridge onto a overground tube line,and saw massive sparks flare up,as hit hit the live rails,although the few attempts before missed the live rails.
4.My grandparents are very impatient,and when i was staying over at their house on time,the ring main fuse blew on the fuse box,and because they are too poor to have a electrician come and replace their crappy 40 year old very dodgy wiring and scorched sockets,and the lighting wire is so old,the insulation is made out of cotton and some paper tubing.So my stupid Grandpa,ran out of fusewire,so he used a nail instead.And when he turned back the old fusebox,sparks flowed down the contacts,and started melting the fusebox.But then even more stupid,he goes and fills a bucket full of water,and pours it directly over the fuseboard,which made the whole fusebox burn up in one big flash.And then we had to get out of his house,and call the fire brigade from the neighbour's house.All because my Grandpa is too thick,and doesn't know how to fix anything.
5. Last but not least. I Found an old fan heater,which did work,but if you turned it to a hot setting,you could smell a burning smell.It turns out that the heating element was very poorly attached,so that it rested 5mm from the plastic casing,and the supply cable to the element was non-heat resistant,and it did not have any heatshrinking when it joined the element.
1. opened a big 30 inch,but old colour tv,whilst still on,and shorted the main capacitors with a screwdriver with thick insulation.The capacitors were rated 650v 33000uf,and after shorting them they were just a huge blob of awful acrid smelling plastic,as well as the screwdriver handle which melted extremely fast,luckerly i dropped it before it electrocuted me.
2. Dropped a tv down 4 flights of stairs,with the back off,and switched on,and attached to an extension lead.
The tube broke,and glass flew everywhere,as well as a loud hiss of the pressure.And then it pulled the socket from the wall,and shorted the contacts,as well as seeing a big 50cm length flash.
3.Threw metal poles,from a bridge onto a overground tube line,and saw massive sparks flare up,as hit hit the live rails,although the few attempts before missed the live rails.
4.My grandparents are very impatient,and when i was staying over at their house on time,the ring main fuse blew on the fuse box,and because they are too poor to have a electrician come and replace their crappy 40 year old very dodgy wiring and scorched sockets,and the lighting wire is so old,the insulation is made out of cotton and some paper tubing.So my stupid Grandpa,ran out of fusewire,so he used a nail instead.And when he turned back the old fusebox,sparks flowed down the contacts,and started melting the fusebox.But then even more stupid,he goes and fills a bucket full of water,and pours it directly over the fuseboard,which made the whole fusebox burn up in one big flash.And then we had to get out of his house,and call the fire brigade from the neighbour's house.All because my Grandpa is too thick,and doesn't know how to fix anything.
5. Last but not least. I Found an old fan heater,which did work,but if you turned it to a hot setting,you could smell a burning smell.It turns out that the heating element was very poorly attached,so that it rested 5mm from the plastic casing,and the supply cable to the element was non-heat resistant,and it did not have any heatshrinking when it joined the element.
When I was 8 years old, I was very much into chemestry. I lived in the Soviet Union at the time, and these guys had no safety regulations as to what can be sold in chemestry kits to school kids, so all sorts of interesting items could be found there. It was not long before our recepie of choice was mixing very pure Magnezium powder with Manganese powder (and a dash of Iron powder for cosmetics
) A small mixture of a couple of grams gave a great sonic blast. Unfortunately the mentality of bigger BiggER better BIGGER (same mentality that has me in audio now) had weld several tin cans together that held about a kilo of the mixture, then attach the top with some epoxy...... At least we had enough sence to put the device in a 2 meter deep concrete manhole, covered with a heavy iron lid. The result? The lid that weighed around 50 kilos was METERS up in the air! (In our area the lids did not twist and lock into place like they do here in the US, but instead relied on mass to keep kids out)
) A small mixture of a couple of grams gave a great sonic blast. Unfortunately the mentality of bigger BiggER better BIGGER (same mentality that has me in audio now) had weld several tin cans together that held about a kilo of the mixture, then attach the top with some epoxy...... At least we had enough sence to put the device in a 2 meter deep concrete manhole, covered with a heavy iron lid. The result? The lid that weighed around 50 kilos was METERS up in the air! (In our area the lids did not twist and lock into place like they do here in the US, but instead relied on mass to keep kids out)Banned
Joined 2002
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