Elenco Yap Box User Manual

YAP BOX KIT

MODEL K-22A

Assembly and Instruction Manual

YAP BOX

SIX EXCITING SOUNDS

Elenco®Electronics, Inc.

Copyright © 2009, 1989 by Elenco®Electronics, Inc. All rights reserved. Revised 2009 REV-H 753222

No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.

PARTS LIST

If you are a student, and any parts are missing or damaged, please see instructor or bookstore.
If you purchased this kit from a distributor, catalog, etc., please contact Elenco®Electronics (address/phone/e­mail is at the back of this manual) for additional assistance, if needed. DO NOT contact your place of purchase
as they will not be able to help you.

RESISTORS

Qty. Symbol Description Color Code Part #

r 1 R15 120Ω 5% 1/4W brown-red-brown-gold 131200
r 2 R1, R9 10kΩ 5% 1/4W brown-black-orange-gold 151000
r 1 R4 18kΩ 5% 1/4W brown-gray-orange-gold 151800
r 2 R6, R7 100kΩ 5% 1/4W brown-black-yellow-gold 161000
r 1 R10 180kΩ 5% 1/4W brown-gray-yellow-gold 161800
r 3 R2, R11, R13 220kΩ 5% 1/4W red-red-yellow-gold 162200
r 1 R3 330kΩ 5% 1/4W orange-orange-yellow-gold 163300
r 4 R5, R8, R12, R14 1MΩ 5% 1/4W brown-black-green-gold 171000

CAPACITORS

Qty. Symbol Value Description Part #

r 1 C2 330pF (331) Discap 223317
r 2 C3, C5 .001μF (102) Discap 231035
r 1C9 .01μF (103) Discap 241031
r 1 C8 .047μF (473) Mylar 244717
r 1C6 .1μF (104) Discap 251010
r 2 C1, C7 10μF Electrolytic (Lytic) 271045
r 2 C4, C10 100μF Electrolytic (Lytic) 281044

SEMICONDUCTORS

Qty. Symbol Value Description Part #

r 8 D1 - D8 1N4148 Diode 314148
r 1 Q1 2N3904 Transistor 323904
r 1 Q2 2N6521 Transistor 326521
r 1 IC1 IC 3086 333086

MISCELLANEOUS

Qty. Symbol Description Part #

r 1 PC Board 510001
r 1 S4 Switch 541010
r 3 Dimple Cap 546100
r 3 S1, S2, S3 Dimple 546101
r 1 BT Battery Snap 590098
r 1 SP1 Speaker 590101
r 1 Case 623350
r 1 Socket 14-Pin 664014
r 1 Label 720400
r 4” Wire 814620

-1-

PARTS IDENTIFICATION

Battery Snap

Transistor

Resistor Capacitor

Discap

Diode

Electrolytic

Capacitor

Speaker

Capacitor

Switch

Mylar

Dimple
Switch

IC & Socket

-2-

INTRODUCTION

The Yap Box circuit diagram is shown on the back
page of this manual. It consists of a special
integrated circuit which contains three built-in
oscillators. By activating each oscillator with the
touch buttons, the exciting sounds are produced.

The Yap Box has three basic circuits, 1) the power
supply, 2) the oscillator circuits, and 3) the output
circuit. We shall analyze each of these circuits to
give you a better understanding of their operations.

The Power Supply

The power supply uses a 9V battery. There are three
push button switches connected to the battery.
These switches supply the power to the oscillators.
The circuit is designed to use no current until the
buttons are pressed. This eliminates the need for an
ON/OFF switch and prevents draining of the battery,
should you forget to turn off the switch.

The Oscillators Circuits

The Yap Box is designed around a special
integrated circuit which contains three complicated
transistor circuits. The theory of operation is too
advanced for our discussion, and we shall limit our
study to the support components in the circuit.

Capacitor C1 is placed across the space gun switch.
When the switch is pressed, the oscillator starts
putting out the complex voltage to produce the
space gun sound. When the switch is released, the
capacitor starts to charge, keeping the current
flowing in the oscillator. As the capacitor charges up,
the current through the oscillator reduces until it
finally drops to zero. This decreasing current causes
the oscillator to give the tailing-off sound when the
button is released.

Capacitor C2 produces the wobbly sound in the
space gun. The charge into C2 is limited by resistor
R1. As the voltage increases across C2, the space
gun frequency will increase. When the space gun
switch is released, the voltage across C2 will drop,
thus giving the lowering of the oscillator frequency.
Capacitor C1 is added to supply voltage to the
space gun during the decay period.

Capacitor C3, C4, C5 and resistors R5, R6, and R7
control the frequency of the siren oscillator.
Capacitors C8, C9 and resistors R2, R3, and R4
control the frequency of the space gun. Capacitor
C6 and resistors R8 and R9 control the frequency of
the laser gun.

The Output Circuit

Figure A shows the output circuit needed to power
the speaker. Transitor Q2 is a power transistor which
drives the speaker. When the voltage at the base of
Q2 goes above 0.7V, the transistor will conduct
current through the collector and emitter of Q2. The
same current flows through the speaker. Thus, when
the oscillator pulses are applied to the base of Q2,
much amplified current pulses flow through the
speaker producing the audio equivalent of the
electrical pulses. Transistor Q1 is a current amplifier
which reduces the loading on the oscillator circuits.
Note that when there are no oscillators active, no
current flows through
the transistors. This
saves battery power
and eliminates the
need for an ON/OFF
switch.

CIRCUIT DESCRIPTION

The Yap Box is a most interesting kit to build. It
produces six exciting sounds: Space Gun, Siren,
Laser Gun, Diesel Horn, Puppy Bark, and Wolf
Whistle. By pressing two or more buttons, other

interesting sounds can be produced.
You can amuse your friends and be a hit at parties.
Use it as and attention getter or a bike horn.

Figure A

BATTERIES

• Do not short circuit the battery terminals.

• Never throw batteries in a fire or attempt to open
it.

• Use only 1.5V “AA” type (not included).

• Insert batteries with correct polarity.

• Non-rechargeable batteries should not be

recharged.

• Do not mix alkaline, standard (carbon-zinc), or
rechargeable (nickel-cadmium) batteries.

• Do not mix old and new batteries.

• Remove batteries when they are used up.

• Batteries are harmful if swallowed, so keep away