DRAWDIO – KIT

Description

Fun and original electronic device to mount on a pencil: by touching with a finger the trace on the paper sheet, it emits a sound whose frequency depends on the distance between the finger and the graphite tip. The operation of our gadget is due to the special circuit used, which is essentially a note generator that can be modulated in frequency by hand contact; more precisely, by connecting one electrode to the graphite and one to the outside of the pencil, we insert the tip (of the pencil) and our body into an electrical circuit that closes by touching the drawn trace with the other hand. Since the graphite deposited when writing with a pencil is electrically conductive, the circuit will present a resistance that depends both on the thickness of the trace and on the distance between tip and hand. Since the circuit we use varies the frequency produced based on the resistance seen between the two points connected inside and outside the pencil, the distance of the hand and the thickness of the stroke make the frequency vary accordingly.

HOW IT WORKS…

We take a pencil in hand… we start drawing a continuous line that gets thicker and thicker… At a certain point we will hear a sound and we will notice that moving the tip back and forth the acoustic note will change in pitch. But how is it possible? The answer is simple: we have connected the two electrodes of a circuit, one to the graphite lead of the pencil and the other to the barrel; by touching the latter with our hand and placing a finger of the free hand on the trace made by the pencil, we insert between the contacts a resistance that varies based on the distance between finger and pencil tip and on the thickness of the trace. The only condition for everything to work: the stroke must be continuous and not interrupted.

THE CIRCUIT

ASSEMBLY SEQUENCE…