untitled

Perusing the parts list........................................................................

In addition to buying the two plastic pumpkins, you have to find the elec-

tronic parts to build the circuits and assemble everything. Here are the parts

lists for the silent pumpkin and the talking pumpkin.

Silent pumpkin parts list

It’s time to go shopping for the bits and pieces used to build the silent pumpkin.

This involves the following parts (several of which are shown in Figure 9-5):

330 ohm resistor (R1, R2)

10 kohm resistor (R3)

10 kohm potentiometer (R4)

150 ohm resistor (R5)

0.001 microfarad ceramic capacitor (C1)

0.1 microfarad ceramic capacitor (C2)

Yellow size T-1^3 ⁄ 4 LED (LED1)

IR LED, TSAL7200 (LED2)

Various other IR LEDs will work. The one we used is advertised to work at

longer distances than standard IR LEDs. We used this one along with the

IR detector specified in the next section because it was easier to get the

gadget to work at a distance up to about 15 feet than with other combina-

tions we tried. See http://www.rentron.comfor a nice listing of similar IR LEDs.

LM555 (IC1)

SPST toggle switch (S1), used as the on/off switch

400-contact breadboard

LED socket, sized for T-1^3 ⁄ 4 LEDs

Four AA battery pack with snap connector

Three 2-pin terminal blocks

Knob (for potentiometer)

Foam (Styrofoam or similar), about 2^1 ⁄ 2 " thick, 12" wide, 12" long

An assortment of different lengths of prestripped short 22 gauge

(AWG) wire

194 Part III: Let There Be Light