[circuit bending]
[introduction]
[tools]
[parts]
[exploring the art]
[how it works]
[direct wiring]
[potentiometers]
[capacitors]
[photo resistors]
[solar cells]
[leds]
[humidity sensors]
[body-contacts]
[reset switch]
[line outputs]
[other techniques]
[cautions]
[closing words]
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Along with
protecting yourself and the components you add to the circuit as you bend it, there are
precautions to take that will protect the circuit itself. If you're working with a rare or
hard to replace circuit, take heed...
During the exploration process using the test lead to search the circuit for bending
points, apply the traveling screwdriver's tip to the various circuit points tested very
briefly -- just for a moment. In this moment beware of the following conditions. Don't try
the connection again if you observe:
>a spark
>a dimming of electronic displays or lights
>a "pop" from the speaker
>a volume decrease or failure of the sound in progress
>a humming in the speaker
>a component heating up on the board
>batteries heating up
As electricity flows its course through a circuit, the resistance of circuit components
often reduces the voltages in the circuit "down stream" of the power supply.
These components are, in many cases, meant to operate on these diminished voltages rather
than the full voltage of the batteries. Due to this, it's best not to jump the battery
voltage into the areas further away in the circuit for fear of overloading them and
causing the conditions listed above. Essentially, this means to avoid the area where the
battery power enters the circuit board during your initial explorations with the
screwdriver-test-lead apparatus.
Another important fact to remember is that while individual new circuit-bending paths may
have no adverse effect upon the circuit when they are switched on by themselves, such
paths in combination with each other might not be so forgiving. In other words, switch
"1" let's say, which activates your first discovered pair of circuit-bending
points, adds a nice warble effect to the instrument's voice and works just fine when
turned on by itself. Switch "2", which activates your 2nd circuit-bending
connection, adds unpredictable pulsing to the instrument's voice and works just fine when
turned on by itself. But you'll notice that when both switches "1" and
"2" are turned on at the same time the speaker volume drops or disappears. Or
you'll notice another of the above trouble signs.
As mentioned previously, eccentric circuitry can cause a crash. Battery supply
interruption may be needed to reset and safeguard the circuit. This is an important
consideration; be sure to install a RESET SWITCH as described toward the end of the
EXPLORING THE ART section, above, in any instrument prone to crash.
The reality is that the new wiring of circuit-bending is compounded in many
convoluted ways as the different controls are combined with each other. This may cause
trouble. Be aware of such switching combinations; avoid them or modify the wiring behind
them by finding another pair of points to wire one of the switches to. Re-test.
On the other hand, this chaotic snowballing of creative short-circuiting is at the
essential and surreal heart of this chance process. There is no way to experience all the
switching combinations as the new wiring is being charted on the board. It is not until
the instrument is complete that it can be fully explored by the designer, since it is not
until then that all discovered connections and new controls are in place at once and can
be combined. At that point magic occurs. The instrument is explored, revealing itself in
ways never evident during the initial, one-effect-at-a-time, discovery process. This is a
wonderful moment.
But to the point: good circuit-bending connections create unusual audio behavior
without taxing the circuit, without draining power and without any destructive effect upon
the electronics at all. Feeling the integrated circuits, resistors and other components on
the circuit board while bending is a very good idea. If a connection is made that causes a
component to become unusually hot (some components will warm up a bit normally), avoiding
that connection is a good idea!
It's best to also avoid using AC adapters to power circuit-bent instruments. This is
because such power converters are known to add noise to circuits as well as damage
electronics due to poor voltage regulation and inadequate surge suppression. Use
high-quality rechargeable batteries with back-ups.
Along the course of circuit-bending, some circuits will be destroyed. As a general rule,
don't try to circuit-bend anything you can't live without. Experience, however, will lead
to more successes than failures, and in time a fascinating collection of instruments will
come about. |