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As an 80s kid, these melody cards were among the first things that piqued my interest for what later lead me to studying electrical engineering / computer archi

by Eduard 5y ago

As an 80s kid, these melody cards were among the first things that piqued my interest for what later lead me to studying electrical engineering / computer architecture and now doing web development. Funny how small experiences can shape a primary school kid's path. Similar experiences include those mini play-with-your-pinkie pianos, putting a 9V battery on the tongue, and the effects of putting a paperclip into an AC power socket.

jaclaz 5y ago
>and the effects of putting a paperclip into an AC power socket. I believe that (in earlier years when electric protections were non existant or just a huge fuse) is one of the origins of survivorship bias ...
- dylan604 5y ago
  I remember the first attic of a house of a certain age to learn that it used to be a thing to not have insulated wiring. Instead, the wiring used a series of insulators as standoffs/guides, but bare exposed copper carrying live current. I was flabbergasted that more homes didn't burn to the ground.
  - jaclaz 5y ago
    Yep, and at least here (Italy) up the '60's or maybe even '70's many older houses were "retrofitted" with what was called "piattina", which you can see here attached to a switch and to a socket: http://www.museolaluce.com/wp-content/uploads/2009/03/vimar40-60.jpg http://www.museolaluce.com/wp-content/uploads/2009/03/vimar4... it was two wires (no earth/ground) and was fixed using tiny nails that were driven in the plastic slip between the two wires, the "luxury" version were these (on the right): http://www.museolaluce.com/wp-content/uploads/2009/03/btic.jpg http://www.museolaluce.com/wp-content/uploads/2009/03/btic.j... but the most common ones had not a real insulator, they were simply steel nails dipped in some rubbery paint. In theory the nail should have never come in contact with any of the two wires, but expecially where there was some corner preventing the nail to be hammered perfectly straight or because of sloppy installation, after a few years (with the rubber/insulation becoming stiff and microcracking) it happened.
  - drfuchs 5y ago
    Look up “Knob And Tube Wiring” on Wikipedia for details (which claim that the wires should have been insulated, but I believe I’ve seen the same as you report, in a California house built in the 1950s).
vidarh 5y ago
> putting a 9V battery on the tongue, and the effects of putting a paperclip into an AC power socket. Removing insulation from a live phone wire with my teeth (I had decided to put an extension in my room without asking for help...) was one of mine, that definitely made me more careful. Went just fine until I closed the circuit with my tongue by accident just as someone called. Not pleasant.
- stavros 5y ago
  > Removing insulation from a live phone wire with my teeth (I had decided to put an extension in my room without asking for help...) was one of mine, that definitely made me more careful. Went just fine until I closed the circuit with my tongue by accident I read this and thought "so what?". > just as someone called. Ahh there it is. Yep, that is indeed not pleasant.
  - vidarh 5y ago
    Yeah, I'd done it once or twice before, and it went well since nobody called, and so I did not for a moment think about the difference. It helped strongly reinforce to make sure stuff is disconnected, not just "not harmful right this instance", before touching it.
    - stavros 5y ago
      I had basically the same experience. I had messed with phone wires a lot, and they were always harmless, until someone called one day. I messed with them more carefully from then on :P
    - 13of40 5y ago
      The 90v(?) AC that comes through the phone line to make it ring was intended to be powerful enough to ring a physical bell. Back before the exchange was automated, home telephones had a hand-cranked generator to produce that signal. According to my dad, kids used to take those out of old phones and use them for all kinds of shenanigans. (Like shocking their friends, siblings, and the dog, I'm guessing.)
robin_reala 5y ago
Without wanting to be that guy, I’m really glad I grew up in a country with shuttered power sockets.
- kingcharles 5y ago
  LOL, so did I. That does not stop a 9-year-old child from putting a paper clip there, I can promise you. The 9-year-old brain is ideally-developed for defeating this type of precaution. Eventually I just found it easier to attach wires to a plug, put the plug in the socket and then just short the wires together.

by Eduard 5y ago

jaclaz 5y ago

>and the effects of putting a paperclip into an AC power socket. I believe that (in earlier years when electric protections were non existant or just a huge fuse) is one of the origins of survivorship bias ...

dylan604 5y ago
I remember the first attic of a house of a certain age to learn that it used to be a thing to not have insulated wiring. Instead, the wiring used a series of insulators as standoffs/guides, but bare exposed copper carrying live current. I was flabbergasted that more homes didn't burn to the ground.
- jaclaz 5y ago
  Yep, and at least here (Italy) up the '60's or maybe even '70's many older houses were "retrofitted" with what was called "piattina", which you can see here attached to a switch and to a socket: http://www.museolaluce.com/wp-content/uploads/2009/03/vimar40-60.jpg http://www.museolaluce.com/wp-content/uploads/2009/03/vimar4... it was two wires (no earth/ground) and was fixed using tiny nails that were driven in the plastic slip between the two wires, the "luxury" version were these (on the right): http://www.museolaluce.com/wp-content/uploads/2009/03/btic.jpg http://www.museolaluce.com/wp-content/uploads/2009/03/btic.j... but the most common ones had not a real insulator, they were simply steel nails dipped in some rubbery paint. In theory the nail should have never come in contact with any of the two wires, but expecially where there was some corner preventing the nail to be hammered perfectly straight or because of sloppy installation, after a few years (with the rubber/insulation becoming stiff and microcracking) it happened.
- drfuchs 5y ago
  Look up “Knob And Tube Wiring” on Wikipedia for details (which claim that the wires should have been insulated, but I believe I’ve seen the same as you report, in a California house built in the 1950s).

vidarh 5y ago

> putting a 9V battery on the tongue, and the effects of putting a paperclip into an AC power socket. Removing insulation from a live phone wire with my teeth (I had decided to put an extension in my room without asking for help...) was one of mine, that definitely made me more careful. Went just fine until I closed the circuit with my tongue by accident just as someone called. Not pleasant.

stavros 5y ago
> Removing insulation from a live phone wire with my teeth (I had decided to put an extension in my room without asking for help...) was one of mine, that definitely made me more careful. Went just fine until I closed the circuit with my tongue by accident I read this and thought "so what?". > just as someone called. Ahh there it is. Yep, that is indeed not pleasant.
- vidarh 5y ago
  Yeah, I'd done it once or twice before, and it went well since nobody called, and so I did not for a moment think about the difference. It helped strongly reinforce to make sure stuff is disconnected, not just "not harmful right this instance", before touching it.
  - stavros 5y ago
    I had basically the same experience. I had messed with phone wires a lot, and they were always harmless, until someone called one day. I messed with them more carefully from then on :P
  - 13of40 5y ago
    The 90v(?) AC that comes through the phone line to make it ring was intended to be powerful enough to ring a physical bell. Back before the exchange was automated, home telephones had a hand-cranked generator to produce that signal. According to my dad, kids used to take those out of old phones and use them for all kinds of shenanigans. (Like shocking their friends, siblings, and the dog, I'm guessing.)

robin_reala 5y ago

Without wanting to be that guy, I’m really glad I grew up in a country with shuttered power sockets.

kingcharles 5y ago
LOL, so did I. That does not stop a 9-year-old child from putting a paper clip there, I can promise you. The 9-year-old brain is ideally-developed for defeating this type of precaution. Eventually I just found it easier to attach wires to a plug, put the plug in the socket and then just short the wires together.