I am claiming dunce of the week

[ThomasHenry]

Okay, how about this one. I'm glad to say it's not me (and even it were, I wouldn't confess it.)<p>I had an instructor who had been an electrical inspector in Iowa back in the 1960's. He told of a homemade house-wiring job he was to inspect. It turns out the guy had wired his entire house with twin-lead 300 ohm antenna cable (because he found it so less expensive than the stuff others were using).<p>And just when you think you've heard it all: I also remember a guy I worked for telling me about a chap who had shingled his own roof by starting at one side, going up and over the apex, down to the other side. I never heard the outcome, but imagine he quickly figured out that one side of the house was dry and the other was suitable only for Noah.<p>My father had an expression which has stuck with me all these years: "People are so damn dumb..."

[Adam Y.]

I take this lab as a part of becoming an electrical engineer. My parnter and I were working on an logic circuit using transistors and resistors. Unfortunately, due to the way the classes are run no one has a clue how transistors work. This was really funny because me and our parnter spent a long time on figuring out why the transistor was drawing power through the base and lighting a led when there was nothing connected to the collector. Then there were a few times we just connected the DVM backwards. That is always fun. "Why is our not gate giving us a positive voltage when it should be a zero?"

[Joseph]

Being a real Melvin, I will just mention one here. I had spent hours finding and replacing about 15 blown parts on a stereo receiver of which one channel had melted down, figuratively speaking. Must have been a Sansui. Well, when it was finally working, I set it back down flat on the bench, on a string of solder braid. Pop! It was truly toast after that one.

[Dean Huster]

My Halfs-heimer's keeps me from remembering any electroniky flubs .... either that, or I'm perfect in that discipline. I do better at flubbing with lots of spectators:<p>Here I am, first in line at the red light, going from a four-lane street to a two-lane highway across the intersection. Light's still red. Traffic's backing up behind me. Red light. Traffic's getting heavy, everybody wanting to get home. Guy pulls up in the lane to my right. Red light. He's in the "Right turn only" lane. Jackass ain't turning right. It's right-on-red here. He isn't turning! Jerk's planning on hitting the gas and cutting in ahead of me and the rest of the traffic behind me. RED LIGHT. Ain't gonna happen!! I watch the cross light. Green. I'm gettin' the jump on him. I've got red. He still ain't turnin'. Cross light turns yellow. Left foot on the brake. Right foot on the gas. Cross light turns red. Foot off the brake. I floor the car. Ain't gonna happen. I shoot across the intersection into the single lane ahead. VICTORIOUS!!!!!!<p>Wife next to me is screaming, "What are you doing!!???! You're running the red light!!"<p>Sheepish now. Oh, yeah. I forgot that the left-turn lanes go first. Danged jackass in the right-only lane .....<p>Jackass ....<p>Jackass ....

[rshayes]

I guess I have to settle for the oldies but goodies:<p>Installing connectors without putting the cable clamp on first.<p>Putting the old Ungar soldering irons on the edge of a bench and then tripping over the cord.<p>Occaisional use of suicide cords.<p>Programming loops on a computer with no exit condition. (Much more spectacular if the computer is doing a form feed on a high speed printer in the middle of the loop.)

[philba]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by stephen:
I guess I have to settle for the oldies but goodies:<p>Installing connectors without putting the cable clamp on first.<p>Putting the old Ungar soldering irons on the edge of a bench and then tripping over the cord.<p>Occaisional use of suicide cords.<p>Programming loops on a computer with no exit condition. (Much more spectacular if the computer is doing a form feed on a high speed printer in the middle of the loop.)<hr></blockquote><p>Yeah, been there. I don't know how many times I've forgotten to put the shrink tubing on.<p>When I was in college (in the dark ages when they used punch cards and batch processing) there was a line printer station that you could get a print out of your card deck. Some moron punched up a whole box of card (r00, iirc) with a row of page feeds on each card, stuck it in and walked away. There was paper every where. quite a sight.

[Edd]

Nothing personally comes to mind on such a comical slant as such as some of the superb stories already presented. (It seems that I too, still go into a transfixed auto pilot mode and forget putting on connector shells or rings; get heat too close to a shrink that still needs to be slipped over the adjacent one being worked on; trip on soldering cords; hope that a solder splash doesn't penetrate into my pants thread weave(or even melt them.)
Might I instead, make an offering of a tidbit of mechanical (Nuts) /and/ electro (Volts) chicanery from waaay back in my high school days?

The Drifter....or..........He just happened to drift into the wrooong place at the wrooong time....

First, a little prefacing....Seems like back in hi school days I had landed a cushy, awe inspiring part time job (What?... I even get paid to boot), after school, in a communications receiver and CB radio plant. The products were mobile receivers used by Fire De-part-mints, Po-lee-ce-us-ses, Highway Petroleums and the, then infant, CB radio emergence. The units were of tube design with their vibrator power supplies. I served as a technical gopher, unpacking components, identifying and dispersing to assembly line and even getting in a bit of soldering and assemblage myself at trying, deadline, rush times.

Each Friday the technical staff would stay late to catch up on any loose ends as well as preparing for next weeks operations. Usually this meant not leaving until 9PM and I was invited to the crews steak nite and gabfest at the towns sole overnight "Mom & Pop" diner. This meant I could put my bike in the bed of a techs pick up and he would take me home later, since it was a weekend....no school, plus the diner was almost a mile off my normal course.

One night the conversation topic drifted towards innovative uses of fireworks as youths, launching cans into the air with them as well as later using a closed section of iron sewer pipe with an empty can dropped down onto a lit firecracker at the bottom to make a tin can cannon. I chipped in and interjected my earlier experiences in developing timed fusings for fireworks and their eventual use in flashing hydrogen balloons up in the air at nighttime. One younger tech added that it might be fun to use that on a firecracker in the diners men's room to liven things up some night......with no real consideration of the probability of the timing or there even being occupancy at a precise time. Rolling that over in the mind, with time, the perfection and construction of the following contrivance emerged.

A precise reconnoitering of the men's room revealed it to be in the order of a common home bathroom with no pressure flushed toilet nor men's urinal. It had the typical sink for hand washing with spare towel and toilet tissue storage underneath in its cabinets along with the common two piece wall mounted commode. A critical note was made of the height that the water tanks clearance was from the floor as well as the fact that it was spaced ~2 in out from the wall to which it was anchored.

This mechanics developed:
The utilization of a common wire coat hanger...a la Mommie Dearest...and its reshaping, starting at its top twisted pair and the squaring off of 4 internal corners such that the reshaping now is making a loooong 3 in wide rectangle using the wire length available. The sideways facing rounded top hook was reformed into a squared off "c" form and at the opposite, very bottom end of the long rectangle, both wires were also simultaneously bent forward into a squared off "c" , but with its dimensions of 2" on the inside of the c, and a mere 1/2" in on the outer "lip" of the c bend. The idea being, that the long rectangular wire form is pushed up the cavity behind the water storage tank with the porcelain lid then being lifted off and the top square C hook being turned forward to then latch onto the lip of the water tank and provide secure vertical downward support, the replaced lid, then hides all. The bottom portion of the wire rectangle with its "c" shaping is to serve as a "support tray". The length of the bottom 2 wires after the point of clearing the bottom of the storage tank down to the c bend serves for the mounting of a "D" cell on the right wires side, with electrical tape, and an uncased leaf switch is placed on the left wires side. That switch's contacts were salvaged from old phone switching relay, with their domed contacts rather than using flat contacts. The two strips were being insulated and supported with bakelite strips at one end, the switch contact leaves were tensioned towards each other so that a normally closed condition was created. This switch gets taped by the bakelite blocks to the left support wire so that the contacts are pointed downwards. In addition, within that wrap, is included a 6 in length bound set of #14 solid insulated (Romex) wires that on their opposite ends, are splayed apart ~ 1 inch. Those wires were stripped bare 1/4" on their ends and ~#30 nichrome wire, salvaged from a ceramic cased WW res after breaking its casing.1/4" of the nichrome was set beside one bared pigtail end and very tightly bound with 1 looong strand of bare copper wire out of the cluster of them from lamp cord wire. The adjacent loose nichrome wire is close wound around a 1/8 " drill bit form ~6 turns and then the balance of nichrome is placed beside the other bared pigtail end and tight cu wire bound, as on the first pigtail, with its surplus nichrome snipped off. The result is the whole wire assembly, with its end heater coil, being repositionable, yet, holding its final positional alignment. A final intercomponent connective wiring is made with #18 stranded hookup wire, initially soldered atop the D's cap to one contact of the leaf switch. The remaining contact of the leaf switch then goes to a length of hook up wire that goes to the D cell ground case and is soldered to it. However, that lead is made ~1 ft too long, such that it can be looped into a 1 turn circular service loop, then that loops cross over points are taped together and the center of that 1 turn loop is snipped open and the resultant two leads bared ~1 inch, this being a makeshift series switch and completing the series circuit, if the wires are twisted together.
The final staging was the cutting of a small rectangle of film negative strip with a small hole at one end to pass fishing cord thru it and tie to it. Final preparation was an approximative test lash up on the home toilet.
This was the sequencing:
A 1/4 in hex nut has fishing cord passed through its center hole and tie looped thru it. The cord then passes down and over the left side of the coat hanger rectangular support wire until it was about an inch below it and then that cord was passed thru the center hole of a heavier 1/2 hex ballast nut and tie looped thru it. Lastly the previously loose cord on the negative insulative strip is pre measured by placing its plastic between the switch contacts with the cord dangling floor ward and that cord is marked by knotting it at about an inch up from the floor. That end is then passed over to the 1/2 in bolt and tie looped thru it.
As a preliminary test, the mechanical setup / operation is this way:
The top 1/4 in nut is placed at center rear of the toilets top cover lid so that the center tube of a full roll of toilet paper rests atop it. This takes up the slack on the line running down the rear of the wall to its terminating 1/2 in nut since the weight of the paper roll and the captive 1/4 in nut inside holds the line taut. There is also that slackened line between the same bottom 1/2 in ballast nut and the insulative strip keeping the leaf switch contacts open.

The operative procedure is this:
If the toilet roll is lifted, the released 1/4 in nut lets the line drop free, with the 1/2 in ballast nut falling towards the floor, and, at its peak momentum, the additionally tethered slackened line becomes taut and jerks the insulator spacer out and closes the leaf switch. The "series switch" wires were twisted together so that the power loop was complete and that filament coil heater now resembles a model airplanes glo plug element with its cherry red glow.
Final installation:
The apparatus was carried in under a trench coat (January) and installation work started with two of the crew "waiting" in line outside the men's bathroom door to "use" it and routing any "urgent need" additional patron to the opened door of the adjunct ladies bathroom. The setup was accomplished with final adjustments of the lines lengths for that specific toilet. Only two variances from the last mock up being made this time, on that afore mentioned "support tray". At the bottom "tray" of the support wire framework were placed three devices, side by side. Those devices being what I believe nowadays are labeled as Whistling Chaser Rockets with Report...my uncles, in their childhood had used what I now find to be a rather demeaning and politically incorrect terminology for them. Specifically, on their construction, they were 1/2 inch cardboard tubes about 6 in long with one ends fuse entering through a formed ceramic plug on into and imbedded into a charge of propellant to be ignited, until, at its end of burn, a sealed off charge would be ignited and go off as a firecracker. The out rush of gases past the tuned plug would make the whistling sound, as well as propelling the unit violently. So, with the last three all important devices now in place, the whole tray was then twisted so as to make their trajectory an angular hit off the cabinetry in front of them. A final test of the glow wire was made and then the "safety switch untwisted" and then, using the flexibility of the #14 pigtail support wiring then permitted its positioning of its end heater wire in amongst the splayed 3 fuses of the rockets.
A final checkout revealed the fresh full roll of toilet paper in its position with an all "generous" 4 squares of tissue being left on the walls toilet roll holder. A final twisting together of the "safety switch wires" and all was then like a "set" mousetrap.

Its Showtime !!! :

The ~75 ft square layout of the diner was such that a corner entry way passed thru a double door spaced out wind block opening into a short hallway that had the check out counter to the right side and a hallway immediately to the left with the men's and lady's rooms on the left in that hallway and employees kitchen entry at the very end of that hallway. Otherwise, walking forward from the checkout stand would have immediately accessed 20 booths on the right and 20 at the end making an L shape with probably 30 tables in the center of the room. All of that perfunctory info was leading up to the fact that they weren't cramped for seating spaces and any "malingerer" patrons presented no problems....for there were for sure to be 6 coffee drinking, talking, laughing.....and very observant.....malingerers on that very night.
The crew congregated at one of the frontal booths that would permit a good viewing of incoming traffic and that all important men's room.
By 10 pm there had been several uses of the men's room but with nothing happening. A fourth member of the crew was dispatched to the unit to "check things out". His return revealed that all looked shipshape with nothing out of place except for the toilet lids being up......ahhh...so... looks like all we have had is a bunch of hand washers and winky-tinkers, with no one conducting any really serious #2 business. We wait......
A little after 10:30.. a 5.5 feet'ish..five o'clock shadow'ishslightly scruffy looking ..20'ish male enters, moving just up to the dining bay and looks about and then spies the men's room and heads straight for it....we wait. After several minutes there seems to be a muffled pop, a bit later possibly another and then shortly..for SURE, this time...a third. The conversational din + the jukebox in the dining room tended to drown things out. After a full 5-10 minutes wait later, the occupant exits at a bit faster than normal pace with his eyes cast downward only making a fast furtive glance to the left into the dining room area and then casting a glance towards the, then unattended, cashier stand and then he was flying right on out the exit door.
I highly feel that he was a hitchhiker, as two major interstate highways cross 50 feet from the diner.
Now....who could say exactly what happened within that small 10 x 8 ft confines. Its for sure that minimal evasive torso movement can be enacted with ones skivvies all the way down around their ankles. That is, unless he hops up, still in his "uncleaned" conditon and is hopping up /about from the missiles violently skittering about on the floor. Also, who knows, that if in that intense degree of panic and excitement, an additional unexpected ...Opus II movement... could have further occurred. It's for sure, that there was certainly some intense reverb-erb-erb-erb-ertion from those "reports", occurring in that small enclosed men's room..
Oh well, so much for the creations of a fertile teenage mind long, long ago....but I will say that it did get me 5 free steak dinners, one from each of the other team members. Plus that unique adventure was ensconced in our memories forever !
73's de Edd
[email protected] .........(Interstellar~~~~Warp~~~Speed)
[email protected].........(Firewalled*Spam*Cookies*Crumbs)


I might also poke up my.... Fiery UFO Explosions in the Night time sky....its all Nuts...no Volts if there is any request/interest for it.

[Clyde Crashkop]

Quote: “The rings were rusty so he wanted to demonstrate a trick where he mixes baking soda in some water, puts a metal electrode in the water with the black ground lead from a battery charger attached. He then attaches the red 12v lead to the metal parts and places them in the water.
He sets the charger to 20 amps and we watch as the rust comes off of the rings and attaches to the electrode.
After an hour he wanted to check the rings ….”
I am surprised that none of you wise guy know it alls didn’t jump on this one. Or maybe you want another entry in this dunce of the week topic. Electrolysis is not very efficient but water + baking soda + 20 amps I am sure would make enough hydrogen to blow little pieces of you and your house into the next county. I will let the self proclaimed know it alls do the math.
Dave

[jwax]

Dunno Dave- do it in an open garage, or outside, and the hydrogen goes off and up on its merry way, assuming no ignition source is around!

[Newz2000]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Dave Hogan:
Electrolysis is not very efficient but water + baking soda + 20 amps I am sure would make enough hydrogen to blow little pieces of you and your house into the next county.<hr></blockquote><p>We did it outside. In the garage with the door open. We were interested in how much hyrdogen we created (we knew about that) but we figured we'd avoid sparks and open flames. Good thing you pointed that out because I wouldn't want someone to come along and try it without knowing that.

[John Abel]

As far as the electrolysis goes I doubt that you were actually passing 20 amps through the water. If you were, you would be making hydrogen at an incredible rate; however using the electrolyte of baking soda there would be a high resistance in the water. If you were forcing this much current through, the water would have been boiling. <p>To make the process a bit more efficient I would recommend using table salt. This does have its down side though. The positive electrode will not only produce oxygen but also some chlorine gas (something to keep your distance from). Most of both of these products will cause the oxidization of the positive electrode. This will quickly erode the metal you are using and cause the water to contain quite a bit of oxide sludge. However the negative electrode will produce lots of little hydrogen bubbles that will peel off flakes of rust. This is also an excellent way to take off paint, just be sure not to mix up the electrical connections.<p>Any acid will also work for an electrolyte, I've read that sulfuric acid minimizes the decomposition of the positive electrode while provides for a good conducting water/electrolyte solution. I have no idea what kind of concentration will give you good results, so if you can get your hands on any sulfuric acid (figuratively), you will have to experiment.

[dacflyer]

Edd Edd Edd >> you sound about as mischevious as me Heeheehee....
i used to make all kinds of home made fireworks and bobby traps.. such fun....<p>*boobie trap = modern day Bra..lol *

[Michael J]

Edd, they say that a picture is worth a
thousand words.<p>

[EPA III]

jwax said,<p>"I was USAF, repairing shot up planes in Vietnam, when (I hear it happens to everybody-once!) after soldering 128 wires on the back of a big ass Cannon connector, discover I forgot to put the locking ring over the wires before soldering.
De-solder 128 wires, curse, add ring, solder 128 wires. Curse. Damn war."<p>I did one better, errr worse I guess. I was working my first job after Vietnam, in a TV station. I stayed late one night after my regular shift to do some wiring on the intercom system. Cannon Connectors, just like his story, but only 15 or 18 conductors thank goodness. I had a cable that ran under the floor and needed the cannon connector on it so I soldered the 15 or so wires. And there was the shell, sitting on the counter. Drat! So I unsoldered all 15 and carefully soldered them a second time. And there was the shell, STILL ON THE COUNTER. AHHHHHHHHHHGGGGG!!!!! One more time. Third time's the charm. I finally got it right. Never told the boss. <p>Paul A.

[Engineer1138]

Wow. Reading all these posts makes me think that my lab partner during *senior year* in EE, who asked me how to tell the polarity of a resistor wasn't that dumb after all