Author Topic: What was your first circuit? Do you still remember it?  (Read 16620 times)

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Offline donmr

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Re: What was your first circuit? Do you still remember it?
« Reply #50 on: July 30, 2017, 03:32:36 pm »
Of course I remember!

It was a 'square' 4.5V battery and a light bulb.
As a kid, it was totally mind blowing to discover that you don't actually need a flashlight to light the bulb.

My dad used to like to demonstrate how you could connect the batteries and bulb with 2 table knives.
 

Offline SeanB

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Re: What was your first circuit? Do you still remember it?
« Reply #51 on: July 30, 2017, 03:44:17 pm »
I remember the first thing I plugged into the mains though, a metal can flourescent lamp starter. Wanted to see the glow, and pushed it into the 5A socket outlet and turned on the power, though I think I did at least remember not to touch it after plugging it in and turning on the power. The starter, along with the black Schipperkie, vanished in the bang, and while the dog did come back for supper, the starter was totally gone. Power tripped out at the new fangled distribution board in the laundry ( Installed a few months before as it had the important thing of earth leakage protection and thus was safer for use with an electric washer and clothes iron for Mom) and I turned it on again, when I recovered my hearing?and sight. Unique board, it had Australian socket outlets on it, thus the wiring was to regular SA 15A socket outlets plugged into the Australian rewireable plugs that came with it.
 

Offline OMyMyOHellYes

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Re: What was your first circuit? Do you still remember it?
« Reply #52 on: July 30, 2017, 07:13:05 pm »
Of course I remember!

It was a 'square' 4.5V battery and a light bulb.
As a kid, it was totally mind blowing to discover that you don't actually need a flashlight to light the bulb.

Quite similar to that  - I think it was in 4th grade.  We were studying some very basic electric concepts in science.  I think I had a C cell battery, some aluminum foil, pieces of wire from a phone cable and a bulb out of a flash light.  I remember after a few attempts and re configurations that I worked it out so that I could have it all laid out and manually switch it.  I think somehow I had two different layers of foil separated by a piece of construction paper for an insulator somewhere in there.  It worked well until I stapled it all down to a board so I could take it to school.  I didn't think through the part about stapling through the insulation ...

OMyMyOHellYes 
 

Offline Roxtronix

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Re: What was your first circuit? Do you still remember it?
« Reply #53 on: November 06, 2022, 12:40:29 pm »
... a very nice bloke at Van Bek electronics in my home town ...

Wow ... that might have been me :)  I worked there in the late 1970s... such good memories. Small retailers selling components with knowledgeable staff just don't seem to be a thing any longer :/  I was a customer there from age 10 and they gave me my first job at 16/17 selling the components in the front and doing repairs in the back.

Sorry about the necro-post  ;)
 
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Offline DavidAlfa

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Re: What was your first circuit? Do you still remember it?
« Reply #54 on: November 06, 2022, 04:18:47 pm »
This one when I was 15 or so, to play N64 emulator:
http://arcadecontrols.com/Mirrors/emulatronia/n64pad/imprimir.htm
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Online NiHaoMike

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Re: What was your first circuit? Do you still remember it?
« Reply #55 on: November 06, 2022, 05:04:40 pm »
A "traffic light" circuit with 2 transistors that switched between red and green LEDs.
This was mine :)


I remember a similar project with a different kit that actually reacted to blowing on the microphone. Anyone else think it might be possible on the above kit by using the speaker as a microphone and the third transistor as an amplifier?
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Offline Sredni

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Re: What was your first circuit? Do you still remember it?
« Reply #56 on: November 06, 2022, 06:00:31 pm »
I remember: a wired telegraph. Two pieces of wood with a small lightbulb and a switch made with a flexible sheet of metal that controlled the other terminal's bulb. Very high tech.
For some reason, neither my parents nor my cousin's seemed to think that drilling a hole in the floor/ceiling to let the wire through was a good idea.

Adults. Go figure.
All instruments lie. Usually on the bench.
 

Online RJSV

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Re: What was your first circuit? Do you still remember it?
« Reply #57 on: November 06, 2022, 08:37:19 pm »
   Guitar Octave Pedal.
   Made a large breadboard set, 3 solderless breadboards using LM-324 OP amps and LM-339 analog comparators.  One half did the input, doing Analog to Digital, using only 4 bits.  That got clocked into RAM, those days the RAM was 4 bits by 256 locations, so I'd used 4 ICs to obtain 1 k samples.
Clocked in, at 8 khz, and clocked out, at 16 khz, for OCTAVE music sound.  (Try listen to older Wes Montgomery guitar talent).
   That circuit was missing a 'zero crossing' coordination; instead it just blindly circulated, the input counter registers, and output counter registers, for addressing the guitar sampling buffer, both operating in just a circular manner, rather than the more correct way, of starting or stopping each sweep, at a consistent zero crossing, to avoid 'glitched' output waveforms.
   More fascinating than the guitar sound, with octave higher 2nd note audible; that whole unsheilded breadboard RADIATED EMF to the surroundings.
That means, the circuit's own input got some trash, and, (sorry FCC) nearby TV receiver sets had hashy screen trash NOISE. ..Fascinating, and not really anticipated RF emissions.
   The memory addresss registers actually used a 2-port shared access to the little 256 X 4 bit RAM.
 

Offline Kleinstein

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Re: What was your first circuit? Do you still remember it?
« Reply #58 on: November 06, 2022, 09:32:43 pm »
I remember is kind of rats nest with 4.5 V batteries and light bulbs and a single on/off switch. The strange part was the single switch could turn one lamp on and another off at the same time. Took me quite some time to understand how this could work with only an on/off switch.
 

Online vk6zgo

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Re: What was your first circuit? Do you still remember it?
« Reply #59 on: November 07, 2022, 01:15:35 am »
Back when I was a kid, we lived out of town, lighting was kerosene lamps, radios were all valve battery sets, & the most "electrical" thing kids played with were battery "Torches" (flashlights).
After messing around with everything else I could wreck, I fixed upon the hapless torches, discovering that, yes, they didn't need the reflector to work.
This was also tied in with my obsession with making a movie projector, after finding an article on a magazine about making a film strip projector.
I didn't know the difference, so as 9 year old, had delusions about what I could make.

When we moved back to the city, at about 11, such things lost their appeal, cars were much more appealing, & I became a little revhead, as they were fun to work on.

Thus, it was not till I was around 14 that I built my first bit of electronics--a "one valve" regenerative radio which didn't work.
(Thinking back, I probably had the feedback winding connections reversed)

The next year, I made a better regen radio which  did work, although not as well as I would have liked.
A couple of years later, I made a proper superhet radio---a "mantel set" for my Mum, which worked Ok for some years.

I went off building stuff for years after that.

I keep planning to revisit those "regen sets" to see  if they were just crap designs, or if it was my poor construction techniques.
 

Offline Wallace Gasiewicz

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Re: What was your first circuit? Do you still remember it?
« Reply #60 on: November 07, 2022, 01:27:18 am »
First tried to breadboard a Receiver with number 27 tubes, Something started on fire,

Then built a AF amp from the back of the RCA tube book, It worked OK but I was never able to get rid of the hum. I think I used old filter caps that were not too good.
It was a push pull with power pentodes. I used transformers from old radios.
 

Offline eti

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Re: What was your first circuit? Do you still remember it?
« Reply #61 on: November 07, 2022, 04:17:21 am »
Battery, bulb, in school.
 

Offline basinstreetdesign

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Re: What was your first circuit? Do you still remember it?
« Reply #62 on: November 07, 2022, 05:04:02 am »
First circuit?  Yep, I was 12 in 1962 and found some books at the library on electronics and HAD to try SOMETHING out.  I can still see the jet of blue-orange flame that shot out of a 5 inch radio speaker voice coil as it answered the age-old question: “What happens if you plug it into the wall?”.   ;D

First not-so-simple circuit?  I built a simple one-tube amplifier from parts hacked out of an old B&W TV.  I had inadvertently wired the power filter cap backwards.  This blew the fuse.  When Mom replaced the fuse we heard a loud bang.  I discovered I had a roomful of acrid smoke and it sent the can out of my bedroom, around 3 corners and down twenty feet of corridor to bounce off the front door of our apartment.  This raised eyebrows.  The fact that it also managed to blow a house fuse got my soldering grounded for a week, to boot.  The parents weren’t pleased.   :palm:
« Last Edit: November 07, 2022, 05:06:08 am by basinstreetdesign »
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Offline jhalar

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Re: What was your first circuit? Do you still remember it?
« Reply #63 on: November 07, 2022, 05:46:46 am »
Around when I was 13 my first circuit was "built" using a Braun Lectron set which was abandoned when a Tandy 100 in 1 appeared one Christmas.

« Last Edit: November 07, 2022, 05:50:20 am by jhalar »
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Offline Circlotron

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Re: What was your first circuit? Do you still remember it?
« Reply #64 on: November 07, 2022, 07:10:28 am »
I was 6 or 7 (mid 1960s) when I got a Denshi Block electronics set, same as in the pic. Mine was a bit earlier than the one in the pic because mine said across the top "let's open an (sic) door to electronics!!" Typical English grammar of some Japanese products of that era. At a similar time next door gave me a commercially made crystal set and a pair of headphones. Later while in grade 4 I took the headphones, some batteries, a good length of wire and a carbon microphone to school for show-and-tell and wowed the whole class. Edit - last pic shows my version.
« Last Edit: November 07, 2022, 07:16:36 am by Circlotron »
 

Offline jonpaul

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Re: What was your first circuit? Do you still remember it?
« Reply #65 on: November 07, 2022, 11:25:47 am »
 

Screwdriver magnetizer with yoke coil and 6X4 tube, 1955

Filament transformer and bridge rectifier/cap to make 12VDC to run model T spark coil to drive tesla coil. 1957

Transistor tester 1960

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Offline unknownparticle

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Re: What was your first circuit? Do you still remember it?
« Reply #66 on: November 07, 2022, 07:47:59 pm »
For me it was a guitar fuzz pedal for a lad in my class at school.  He was in a band playing lead guitar and fancied himself as the next Jimmy Page!!
The project was out of Everyday Electronics mag.  Problem was I couldn't test it before he tried it, as I don't have a guitar or amp.  Gave it to him on a Friday afternoon and he gave it back to me on the Monday and said it doesn't do anything!  So I checked all my work, it was on veroboard, so I was suspecting a wrong connection somewhere but I couldn't find any mistakes. So I looked at the circuit and layout in the mag for ages, and eventually found a layout error!!  I was gobsmacked at the time, I was really shocked that a/ the mag made a mistake, and b/ I found it!
So, I corrected that and arranged to take it over to his place for a test run!  It was quite intimidating for a schoolboy to turn up to a band practice with these edgy dudes with attitude!  So we connected it up and he played a few chords with me trying the controls and it worked really well, he was well pleased as were all the other guys!  He wanted it modifying though, with a foot switch to turn the fuzz on and off, that was a bit tricky but I managed it and all was good!  My cool rating went to 10 at school after that!
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Offline ccktek

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Re: What was your first circuit? Do you still remember it?
« Reply #67 on: November 07, 2022, 11:25:15 pm »
My memory of my first circuit is one of my most formative. 

When I was 6 my father brought home from the hardware store a large carpentry nail, a length of bell wire, several small steel brads, and a No. 6 dry cell.  We wound the wire on the nail and connected the ends of the wire to the cell, magnetizing the nail, which attracted the brads.  To me this action at a distance was (and still is) miraculous.  I’d witnessed a consequence of Ampere’s law.  Maxwell would come much later.
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Offline brucehoult

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Re: What was your first circuit? Do you still remember it?
« Reply #68 on: November 08, 2022, 02:25:23 am »
My memory of my first circuit is one of my most formative. 

When I was 6 my father brought home from the hardware store a large carpentry nail, a length of bell wire, several small steel brads, and a No. 6 dry cell.  We wound the wire on the nail and connected the ends of the wire to the cell, magnetizing the nail, which attracted the brads.  To me this action at a distance was (and still is) miraculous.  I’d witnessed a consequence of Ampere’s law.  Maxwell would come much later.

Similar except we used part of an old hacksaw blade, fixed at one end, and arranged so the current for the solenoid went through the hacksaw blade, until movement towards the solenoid broke the circuit.
 

Offline eti

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Re: What was your first circuit? Do you still remember it?
« Reply #69 on: November 08, 2022, 08:56:28 am »
I remember: a wired telegraph. Two pieces of wood with a small lightbulb and a switch made with a flexible sheet of metal that controlled the other terminal's bulb. Very high tech.
For some reason, neither my parents nor my cousin's seemed to think that drilling a hole in the floor/ceiling to let the wire through was a good idea.

Adults. Go figure.

A horse-powered drill? Wow. Did you get Swan or Edison to invest?

When you mentioned telegraph, I pictured you in a top hat and tails, working by lamplight 😁
 

Offline jonovid

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Re: What was your first circuit? Do you still remember it?
« Reply #70 on: November 08, 2022, 10:30:13 am »
 the two transistor flip flop circuit & before that, a torch circuit on a block of wood
Hobbyist with a basic knowledge of electronics
 

Offline Electroplated

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Re: What was your first circuit? Do you still remember it?
« Reply #71 on: November 08, 2022, 09:52:47 pm »
First electrical circuit, battery and bulb featured in a Janet and John kids book when I was 6 years old, first electronic circuit, way back in 1964, a EL84 (iirc) valve amp and output transformer from a scrap radiogram, had a photograph of it until a few years ago, was also my first introduction to the theory of electrocution and why valve HT is derived from a transformer and not a direct feed of 230v mains  :)
50 years working with electronics and I still wonder how small parts can have all that smoke inside !
 

Online RJSV

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Re: What was your first circuit? Do you still remember it?
« Reply #72 on: November 08, 2022, 10:09:22 pm »
   Electrocution is over-rated. NOT.
   Somewhere there, 5th grade at 10 years old, figured out you could hook toy train transformer 10 vac output to another toy train transformer, 'backwards', into the 10 volt terminals, that generates voltage back up at 120 vac.
   Problem happened right away, when I GRABBED the wires, clumsy, and got shocked, through the hand.
Lucky, maybe simply due to no ground path, but it would definitely have caused internal burns...very serious (potentially), but I let go fast.
 

Offline brucehoult

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Re: What was your first circuit? Do you still remember it?
« Reply #73 on: November 08, 2022, 11:39:18 pm »
   Electrocution is over-rated. NOT.
   Somewhere there, 5th grade at 10 years old, figured out you could hook toy train transformer 10 vac output to another toy train transformer, 'backwards', into the 10 volt terminals, that generates voltage back up at 120 vac.
   Problem happened right away, when I GRABBED the wires, clumsy, and got shocked, through the hand.
Lucky, maybe simply due to no ground path, but it would definitely have caused internal burns...very serious (potentially), but I let go fast.

A 600V+ mains supply can pump 4A through the body, causing severe internal burns.

A 1960s Hornby train transformer puts out about 2A at 12-14 VAC. If you use a second identical one to convert back to to 120 V then you're going to have no more than 200 mA (or 100 mA for 240 V) through a short circuit, and a less through a human body. That's a huge difference to grabbing mains directly.
 

Online themadhippy

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Re: What was your first circuit? Do you still remember it?
« Reply #74 on: November 08, 2022, 11:43:30 pm »
Quote
   Somewhere there, 5th grade at 10 years old, figured out you could hook toy train transformer 10 vac output to another toy train transformer, 'backwards', into the 10 volt terminals, that generates voltage back up at 120 vac.
At around 8 i discovered a mechano set motor in series with the secondary of a bell transformer produced similar results,and was portable so could be used in the school playground.Another early project was the sweary box,4 7 segment displays,a rotary switch and a load of diodes,turn the switch and varies swear words would appear on the display.
 
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