quick circuit bending question



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quick circuit bending question

Postby Confuzzled » Tue Oct 10, 2017 1:13 pm

Years ago when I first started dabbling with circuit bending a friend of mine at work (who happened to be an engineer in electronics) wired up a 1/4" output to a toy he helped me bend and put a resistor attached to the plug. I'll take pics and add it to the post, but now that I'm getting back into it I have to ask why?

Is it always needed? How do you judge when it's needed?
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Re: quick circuit bending question

Postby oscillateur » Tue Oct 10, 2017 9:41 pm

Typically toys like that have a speaker, which has a resistance (usually 8-16 ohms).
That resistor basically simulates that (and makes the signal a bit less hot I think).

It's almost always a good idea to do that.
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Re: quick circuit bending question

Postby crochambeau » Thu Oct 12, 2017 9:14 pm

Series resistances can limit the amount of damage a semi conductor will risk if everything goes "wrong". I know lots of people who just make direct connections with wires and have a blast. I've also noticed sometimes stuff gets broken in the process and never recovers.

There might be a correlation there.

(hint hint)

Resistance produces different results though, so, it's up to you. I agree it's good engineering practice to have limiting resistances in place.
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Re: quick circuit bending question

Postby BetterOffShred » Fri Oct 13, 2017 11:10 am

I'm no Scientist of Electrical Elegance or anything, but a fine example for me is the LED... if you don't run a current limiting resistor in front (or behind) an LED, they will pull "infinite current" and pop in a matter of seconds or less. Any device that "pulls current" need some sort of resistive load to limit what happens with the current. E=I*R So if you give it 9 Volts (E) and 1000 Ohms of resistance.. I = E/R.. or .009 amps. 9 miliamps. boom. Conversely, if your R is approximately 0.. any number divided by approximately zero is infinity. Obviously we can't divide by zero, but even a piece of wire has a _little_ resistance, the point being your current will go as high as the power producing device will allow, and things break as crochambeau says :)

It's the same thing in some power networks on pedals, the 9V in runs right through a 100R resistor to "stabilize" the power source. I had a couple pedals that were noisy as balls, threw a 100R in series with the + wire, way quieter. Theres science and big words, but I don't know them. I tinker
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