Project 242 Copyright © 2012 by ELENCO® All rights reserved. No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
Table of Contents Basic Troubleshooting Parts List MORE About Your Snap Circuits® Parts MORE DO’s and DON’Ts of Building Circuits MORE Advanced Troubleshooting Project Listings Projects 102 - 305 Other Fun Elenco® Products 1 2 3 4 5 6, 7 8 - 73 74 1. Most circuit problems are due to incorrect assembly. Always double-check that your circuit exactly matches the drawing for it. 2. Be sure that parts with positive/negative markings are positioned as per the drawing. 3.
Parts List (Colors and styles may vary) Symbols and Numbers Note: There are additional part lists in your other project manuals. Important: If any parts are missing or damaged, DO NOT RETURN TO RETAILER. Call toll-free (800) 533-2441 or e-mail us at: help@elenco.com. Customer Service • 150 Carpenter Ave. • Wheeling, IL 60090 U.S.A. Qty. ID Name r3 1 r3 Symbol Part # Qty.
MORE About Your Snap Circuits® Parts (Part designs are subject to change without notice). Note: There is additional information in your other project manual. The green LED (D2) works the same as the red LED (D1) and the 6V lamp (L2) works the same as the 2.5V lamp; these are described in the projects 1-101 manual. Resistors “resist” the flow of electricity and are used to control or limit the electricity in a circuit. Snap Circuits® includes 100Ω (R1), 1KΩ (R2), 5.
DO’s and DON’Ts of Building Circuits After building the circuits given in this booklet, you may wish to experiment on your own. Use the projects in this booklet as a guide, as many important design concepts are introduced throughout them. Every circuit will include a power source (the batteries), a resistance (which might be a resistor, lamp, motor, integrated circuit, etc.), and wiring paths between them and back.
MORE Advanced Troubleshooting (Adult supervision recommended) Elenco® is not responsible for parts damaged due to incorrect wiring. If you suspect you have damaged parts, you can follow this procedure to systematically determine which ones need replacing: 1. - 9. Refer to project manual 1 (projects 1-101) for testing steps 1-9, then continue below. Test both lamps (L1, L2) and battery holders in test step 1, all blue snap wires in step 3, and both LEDs (D1, D2) in step 5. 10. 1KΩ (R2), 5.
Project Listings Project # 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 Description Page # Batteries in Series 8 Ticking Screecher 8 Spacey Fan 9 Two-Transistor Light Alarm 9 Light-Controlled Alarm 9 Automatic Street Lamp 10 Voice-Controlled Rays of Light 10 Blowing Off the Electric Light 10 Adjustable Tone Generator 11 Photosensitive Electronic Organ 11 Electronic Cicada 11 Light & Sounds 12 More Light & Sounds 12 M
Project Listings Project # 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 -7- Description Page # Make Your Own Battery (II) 36 Make Your Own Battery (III) 36 Tone Generator 37 Tone Generator (II) 37 Tone Generator (III) 37 Tone Generator (IV) 37 More Tone Generator 38 More Tone Generator (II) 38 More Tone Generator (III) 38 Music Radio Station 39 Alarm Radio Station 39 Standard Transistor Circuit 39 Motor & Lamp by So
Project #102 Batteries in Series OBJECTIVE: To show the increase in voltage when batteries are connected in series. When you turn on the slide switch (S1), current flows from the batteries through the slide switch, the 100Ω resistor (R1), the LED (D1), through the LED (D2), and back to the second group of batteries (B1). Notice how both LED’s are lit. The voltage is high enough to turn on both LED’s when the batteries are connected in series.
Project #104 Spacey Fan OBJECTIVE: To build a fan with sound that is activated by light. Place the fan onto the motor (M1). Sounds are heard if light shines on the photoresistor (RP) OR if you press the press switch (S2), the fan may start to spin, but will only get to high speed if you do BOTH. Try various combinations of shining light and holding down the press switch. ! WARNING: Moving parts. Do not touch the fan or motor during operation. Do not lean over the motor.
Project #107 Automatic Street Lamp OBJECTIVE: To show how light is used to control a street lamp. Press the press switch (S2) on and set the adjustable resistor (RV) so the lamp (L2) just lights. Slowly cover the photoresistor (RP) and the lamp brightens. If you place more light at the photoresistor the light dims. This is an automatic street lamp that you can turn on by a certain darkness and turn off by a certain brightness.
Project #110 Adjustable Tone Generator OBJECTIVE: To show how resistor values change the frequency of an oscillator. Turn on the slide switch (S1); the speaker (SP) will sound and the LED (D1) will light. Adjust the adjustable resistor (RV) to make different tones. In an oscillator circuit, changing the values of resistors or capacitors can vary the output tone or pitch. Project #111 Photosensitive Electronic Organ OBJECTIVE: To show how resistor values change the frequency of an oscillator.
Project #113 Light & Sounds OBJECTIVE: To build a police siren with light. Turn on the slide switch (S1). A police siren is heard and the lamp (L1) lights. Project #114 Project #115 Project #116 Project #117 More Light & More Light & More Light & More Light & Sounds Sounds (II) Sounds (III) Sounds (IV) OBJECTIVE: To show a variation of the circuit in project #113. OBJECTIVE: To show a variation of the circuit in project #113. OBJECTIVE: To show a variation of the circuit in project #113.
Project #118 Motor Speed Detector OBJECTIVE: To show how to make electricity in one direction. When building the circuit, be sure to position the motor (M1) with the positive (+) side snapped to the 470μF capacitor (C5). Turn on the slide switch (S1), nothing will happen. It is a motor speed detector, and the motor isn’t moving. Watch the LED (D2) and give the motor a good spin CLOCKWISE with your fingers (don’t use the fan blade); you should see a flash of light.
Project #120 Optical Transmitter & Receiver OBJECTIVE: using light. To show how information can be transmitted Build the circuit shown. Connect the photoresistor (RP) to the circuit using the red & black jumper wires. Place the photoresistor upside down over the red LED (D1), so the LED goes inside the photoresistor. Turn on both switches (hold down the press switch button). Music plays on the speaker, even though the two parts of the circuit are not electrically connected.
Project #122 Space War Radio OBJECTIVE: To transmit Space War sounds to a AM radio. Place the circuit next to an AM radio. Tune the radio so no stations are heard and turn on the slide switch (S1). You should hear the space war sounds on the radio. The red LED (D1) should also be lit. Adjust the variable capacitor (CV) for the loudest signal. Push the press switch (S2) to change the sound. You have just performed the experiment that took Marconi (who invented the radio) a lifetime to invent.
Project #124 NPN Amplifier OBJECTIVE: To compare transistor circuits. There are three connection points on an NPN transistor (Q2), called base (marked B), emitter (marked E), and collector (marked C). When a small electric current flows from the base to the emitter, a larger (amplified) current will flow from the collector to the emitter. Build the circuit and slowly move up the adjustable resistor (RV) control. When the LED (D2) becomes bright, the lamp (L2) will also turn on and will be much brighter.
Project #126 Sucking Fan OBJECTIVE: To adjust the speed of a fan. Build the circuit, and be sure to orient the motor (M1) with the positive (+) side down as shown. Turn it on, and set the adjustable resistor (RV) for the fan speed you like best. If you set the speed too fast then the fan may fly off the motor. Due to the shape of the fan blades and the direction the motor spins, air is sucked into the fan and towards the motor. Try holding a piece of paper just above the fan to prove this.
Project #130 NPN Collector OBJECTIVE: To compare transistor circuits. OBJECTIVE: To compare transistor circuits. Compare this circuit to that in project #128, it is the NPN transistor (Q2) version and works the same way. Which circuit makes the lamp (L2) brighter? (They are about the same because both transistors are made from the same materials). Compare this circuit to that in project #129. It is the NPN transistor (Q2) version and works the same way.
Project #134 Buzzing in the Dark OBJECTIVE: To make a circuit that buzzes when the lights are off. OBJECTIVE: To build a human buzzer oscillator. This circuit makes a high-frequency screaming sound when light shines on the photoresistor (RP), and makes a buzzing sound when you shield the photoresistor. Remove the photoresistor (RP) from the circuit in project #134 and instead touch your fingers across where it used to be (points B1 and D1 on the grid) to hear a cute buzzing sound.
Project #139 High Sensitivity Voice Doorbell OBJECTIVE: To build a highly sensitive voice-activated doorbell. Build the circuit and wait until the sound stops. Clap or talk loud a few feet away and the music plays again. The microphone (X1) is used here because it is very sensitive. Project #140 Louder Doorbell OBJECTIVE: To build a loud highly sensitive voice-activated doorbell. Replace the 6V lamp (L2) with the antenna coil (A1), the sound is louder now.
Project #145 Radio Music Alarm OBJECTIVE: To build a radio music alarm. You need an AM radio for this project. Build the circuit on the left and turn on the slide switch (S1). Place it next to your AM radio and tune the radio frequency to where no other station is transmitting. Then, tune the adjustable capacitor (CV) until your music sounds best on the radio. Now connect a jumper wire between X and Y on the drawing, the music stops.
Project #151 Blow Off a Space War OBJECTIVE: To turn off a circuit by blowing on it. Build the circuit and turn it on, you hear a space war. Since it is loud and annoying, try to shut it off by blowing into the microphone (X1). Blowing hard into the microphone stops the sound, and then it starts again. Project #152 Series Lamps OBJECTIVE: To compare types of circuits. Project #153 Parallel Lamps OBJECTIVE: To compare types of circuits. Turn on the slide switch (S1) and both lamps (L1 & L2) will light.
Project #154 Fire Fan Symphony OBJECTIVE: To combine sounds from the music, alarm, and space war integrated circuits. Build the circuit shown and add the jumper to complete it. Note that in one place two (2) single snaps are stacked on top of each other. Also, note that there is a 2-snap wire on layer 2 that does not connect with a 4-snap wire that runs over it on layer 4 (both touch the music IC).
Project #158 Police Car Symphony OBJECTIVE: To combine sounds from the integrated circuits. Build the circuit shown and add the two (2) jumper wires to complete it. Note that in one place two (2) single snaps are stacked on top of each other. Turn it on and press the press switch (S2) several times and wave your hand over the photoresistor (RP) to hear the full spectrum of sounds that this circuit can create.
Project #162 Static Symphony OBJECTIVE: To combine sounds from the integrated circuits. Project #163 Static Symphony (II) OBJECTIVE: See project #162. Build the circuit shown. Note that in some places parts are stacked on top of each other. Turn it on and press the press switch (S2) several times and wave your hand over the photoresistor (RP) to hear the full spectrum of sounds that this circuit can create. Have fun! Project #164 Capacitors in Series OBJECTIVE: To compare types of circuits.
Project #166 Water Detector OBJECTIVE: To show how water conducts electricity. Build the circuit at left and connect the two jumpers to it, but leave the loose ends of the jumpers lying on the table initially. Turn on the slide switch (S1) - the LED (D1) will be dark because the air separating the jumpers has very high resistance. Touch the loose jumper ends to each other and the LED will be bright, because with a direct connection there is no resistance separating the jumpers.
Project #168 NPN Light Control OBJECTIVE: To compare transistor circuits. OBJECTIVE: To compare transistor circuits. Turn on the slide switch (S1), the brightness of the LED (D2) depends on how much light shines on the photoresistor (RP). The resistance drops as more light shines, allowing more current to the NPN (Q2). Turn on the slide switch (S1), the brightness of the LED (D2) depends on how LITTLE light shines on the photoresistor (RP).
Project #172 Red & Green Control OBJECTIVE: To demonstrate how the adjustable resistor works. Turn on the circuit using the slide switch (S1) and/or the press switch (S2) and move the adjustable resistor’s (RV) control lever around to adjust the brightness of the LED’s (D1 & D2). When the adjustable resistor is set to one side, that side will have low resistance and its LED will be bright (assuming the switch on that side is ON) while the other LED will be dim or OFF.
Project #176 Blow Off a Doorbell OBJECTIVE: To turn off a circuit by blowing on it. Project #177 Blow Off a Candle OBJECTIVE: To turn off a circuit by blowing on it. Build the circuit and turn it on; music plays. Since it is loud and annoying, try to shut it off by blowing into the microphone (X1). Blowing hard into the microphone stops the music, and then it starts again. Project #178 Blow On a Doorbell OBJECTIVE: To turn on a circuit by blowing on it. Replace the speaker (SP) with the 6V lamp (L2).
Project #180 Screaming Fan OBJECTIVE: To have an adjustable resistance control a fan and sounds. Project #181 Whining Fan OBJECTIVE: To make different sounds. Build the circuit on the left and place the fan onto the motor (M1). Turn on the slide switch (S1) and move the setting on the adjustable resistor (RV) across its range. You hear screaming sounds and the fan spins. ! Project #182 Light Whining OBJECTIVE: To make different sounds.
Project #185 Whiner OBJECTIVE: To build a circuit that makes a loud whine. Project #186 Lower Pitch Whiner OBJECTIVE: To show how adding capacitance reduces frequency. Build the circuit, turn it on, and move the setting on the adjustable resistor (RV). It makes a loud, annoying whine sound. The green LED (D2) appears to be on, but it is actually flashing at a very fast rate. Project #187 Hummer Project #188 Adjustable Metronome OBJECTIVE: To show how adding capacitance reduces frequency.
Project #190 Hissing Foghorn OBJECTIVE: To build a transistor oscillator that can make a foghorn sound. Build the circuit on the left and move the adjustable resistor (RV) setting. Sometimes it will make a foghorn sound, sometimes it will make a hissing sound, and sometimes it will make no sound at all. Project #191 Hissing & Clicking OBJECTIVE: To build an adjustable clicking oscillator. Project #192 Video Game Engine Sound OBJECTIVE: To build a human oscillator.
Project #193 Light Alarm OBJECTIVE: alarm. To build a transistor light Project #194 Brighter Light Alarm OBJECTIVE: To build a brighter transistor light alarm. Build the circuit with the jumper connected as shown, and turn it on. Nothing happens. Break the jumper connection and the light turns on. You could replace the jumper with a longer wire and run it across a doorway to signal an alarm when someone enters. Project #195 Lazy Fan OBJECTIVE: To build a fan that doesn’t work well.
Project #197 Water Alarm OBJECTIVE: To sound an alarm when water is detected, tone will vary with salt content. Build the circuit at left and connect the two (2) jumpers to it, place the loose ends of the jumpers into an empty cup (without them touching each other). Press the press switch (S2) - nothing happens. Add some water to the cup and an alarm will sound. Add salt to the water and the tone changes. You can also test different liquids and see what tone they produce.
Project #199 Pitch OBJECTIVE: To show how to change the pitch of a sound. Build the circuit on the left, turn it on, and vary the adjustable resistor (RV). The frequency or pitch of the sound is changed. Pitch is the musical profession’s word for frequency. If you’ve had music lessons, you may remember the music scale using chords such as A3, F5, and D2 to express the pitch of a sound. Electronics prefers the term frequency, as in when you adjust the frequency on your radio.
Project #203 Make Your Own Battery OBJECTIVE: To demonstrate how batteries can store electricity. Build the circuit, then connect points Y & Z (use a 2-snap wire) for a moment. Nothing appears to happen, but you just filled up the 470μF capacitor (C5) with electricity. Now disconnect Y & Z and instead touch a connection between X & Y. The green LED (D2) will be lit and then go out after a few seconds as the electricity you stored in it is discharged through the LED and resistor (R2).
Project #206 Tone Generator OBJECTIVE: To build a high-frequency oscillator. Build the circuit and turn it on, you hear a high-frequency sound. Project #208 Project #209 Project #207 Tone Tone Tone Generator (II) Generator (III) Generator (IV) OBJECTIVE: To lower the frequency of a tone by increasing circuit capacitance. Place the 0.02μF capacitor (C1) on top of the whistle chip (WC) in the preceding circuit, you hear a middle-frequency sound.
Project #210 More Tone Generator OBJECTIVE: To build a middle-frequency oscillator. Build the circuit, as the name suggests this circuit is similar to that in project #206. Turn it on, you hear a middle-frequency sound. Project #211 More Tone Generator (II) Project #212 More Tone Generator (III) OBJECTIVE: To lower the frequency of a tone by increasing circuit capacitance. OBJECTIVE: To lower the frequency of a tone by increasing circuit capacitance. Place the 0.02μF capacitor (C1) or the 0.
Project #213 Music Radio Station OBJECTIVE: To create music and transmit it to a radio. Project #214 Alarm Radio Station OBJECTIVE: To create music and transmit it to a radio. You need an AM radio for this project. Build the circuit shown on the left and turn on the slide switch (S1). Place it next to your AM radio and tune the radio frequency to where no other station is transmitting. Then, tune the variable capacitor (CV) until your music sounds best on the radio.
Project #216 Motor & Lamp by Sound OBJECTIVE: To control a motor using light. Turn the slide switch (S1) on, the motor (M1) spins and the lamp (L2) lights. As you move your hand over the photoresistor (RP), the motor slows. Now place finger onto the photoresistor to block the light. The motor slows down. In a few seconds, the motor speeds up again. ! Project #217 WARNING: Moving parts. Do not touch the fan or motor during operation. Do not lean over the motor.
Project #219 Laser Gun with Limited Shots OBJECTIVE: To build a circuit with laser gun sounds and a limited amount of shots. When you press the press switch (S2), the alarm IC (U2) should start sounding a very loud laser gun sound. The speaker (SP) will sound, simulating a burst of laser energy. You can shoot long repeating laser burst, or short zaps by tapping the trigger switch. But be careful, this gun will run out of energy and you will have to wait for the energy pack (C5) to recharge.
Project #222 Transistor Amplifiers OBJECTIVE: To learn about the most important component in electronics. When you place one or more fingers across the two snaps marked X & Y you will notice the LED (D1) turns on. The two transistors are being used to amplify the very tiny current going through your body to turn on the LED. Transistors are actually electrical current amplifiers. The PNP transistor (Q1) has the arrow pointing into the transistor body.
Project #225 Auto-Off Night-Light OBJECTIVE: To learn about one device that is used to delay actions in electronics. When you turn on the slide switch (S1) the first time the LED (D1) will come on and very slowly get dimmer and dimmer. If you turn the slide switch (S1) off and back on after the light goes out it will NOT come on again. The 470μF capacitor (C5) has charged up and the NPN transistor amplifier (Q2) can get no current at its input to turn it on. This circuit would make a good night-light.
Project #228 Morse Code Generator OBJECTIVE: To make a Morse code generator and learn to generate code. When you press down on the press switch (S2) you will hear a tone. By pressing and releasing the press switch you can generate long and short tones called Morse code. For International code, a short tone is represented by a “+”, and a long tone by a “–”. See the chart below for letter or number followed by code.
Project #233 Mind Reading Game OBJECTIVE: To make an electronic game of mind reading. Shorting Bar for W, X, Y, or Z. Setup: Player 1 sets up by placing one shorting bar under the paper on row A, B, C, or D. Player 2 must NOT know where the shorting bar is located under the paper. Paper Sheet to hide position of shorting bar. The object is for Player 2 to guess the location by placing his shorting bar at positions W, X, Y, or Z. In the drawing on the left, Player 1 set up at position “D”.
Project #234 Paper Sheet to hide position of shorting bar. Shorting Bar for W, X, Y, or Z. Enhanced Quiet Zone Game OBJECTIVE: Make and play the electronic game of “Quiet Zone”. Use the circuit from project #233, but place three (3) 2-snap wires (“shorting bars”) under paper as shown on left. Setup: Player 1 sets the “Quiet Zone” by placing three (3) shorting bars under the paper on row A, B, C, or D, leaving only one open. Player 2 must NOT know where the shorting bars are located under the paper.
Project #236 Sound Wave Magic OBJECTIVE: To show how sound waves travel on a paper surface. Build the circuit shown on the left and connect the speaker (SP) using the two (2) jumper wires. Then, lay the speaker on a flat hard surface. Paper Tray Salt Setup: Use some paper and scissors to cut out a rectangular pattern. Use the one shown below as a guide. Use colored paper if available. Fold at the points shown. Scotch tape the corners so the tray has no cracks at the corners.
Project #238 Trombone OBJECTIVE: To build an electronic trombone that changes pitch of note with slider bar. When you turn on the slide switch (S1) the trombone should start playing. To change the pitch of the note, simply slide the adjustable resistor (RV) control back and forth. By turning the slide switch on and off and moving the slider, you will be able to play a song much like a trombone player makes music.
Project #240 Power Amplifier OBJECTIVE: To check stability of power amplifier with open input. When you turn on the slide switch (S1), the power amplifier IC (U4) should not oscillate. You should be able to touch point X with your finger and hear static. If you do not hear anything, listen closely and wet your finger that touches point X. High frequency clicks or static should be coming from speaker (SP) indicating that the amplifier is powered on and ready to amplify signals.
Project #242 AM Radio OBJECTIVE: To make a complete working AM radio. When you turn on the slide switch (S1), the integrated circuit (U5) should amplify and detect the AM radio waves all around you. The variable capacitor (CV) can be tuned to the desirable station. Varying the adjustable resistor (RV) will make the audio louder or softer. The power amplifier IC (U4) drives the speaker (SP) to complete the AM radio project.
Project #243 Fire Engine Symphony OBJECTIVE: To combine sounds from the music, alarm, and space war integrated circuits. Build the circuit shown and add the jumper to complete it. Note that in two places two single snaps are stacked on top of each other. Also, note that there is a 2-snap wire on layer 2 that does not connect with a 4-snap wire that runs over it on layer 4 (both touch the music IC, U1).
Project #246 Two-Finger Touch Lamp OBJECTIVE: To show that your body can be used as an electronic component. Build the circuit on the left. You’re probably wondering how it can work, since one of the points on the NPN transistor (Q2) is unconnected. It can’t, but there is another component that isn’t shown. That component is you. Touch points X & Y with your fingers. The LED (D1) may be dimly lit. The problem is your fingers aren’t making a good enough electrical contact with the metal.
Project #248 Space Battle OBJECTIVE: To make space battle sounds. Project #249 Space Battle (II) OBJECTIVE: To show how light can turn “ON” an electronic device. Build the circuit shown on the left. Activate the circuit by turning on the slide switch (S1) or pressing the press switch (S2), do both several times and in combination.
Project #252 Storing Electricity OBJECTIVE: To store electricity in a capacitor. Turn the slide switch (S1) on and connect points A & B with a 2-snap wire. The green LED (D2) will flash and the 470μF capacitor (C5) will be charged with electricity. The electricity is now stored in the capacitor. Disconnect points A & B. Connect points B & C and there will be a flash from the 6V lamp (L2). The capacitor discharges through the resistor to the base of the NPN transistor (Q2).
Project #255 Radio Music Burglar Alarm OBJECTIVE: To build an alarm that plays music on the radio. Place the circuit next to an AM radio. Tune the radio so no stations are heard. Set the slide switch (S1) on. You should hear the song play. The red LED (D1) should also be lit. Adjust the variable capacitor (CV) for the loudest signal. Connect a jumper wire across points A & B and the music stops. The transistor (Q2) acts like a switch connecting power to the music IC (U1).
Project #257 Motion Detector OBJECTIVE: Build a circuit that detects motion. Set the adjustable resistor (RV) to the center position. Turn the slide switch (S1) on and the LED (D1) lights. Wave your hand over the photoresistor (RP) and the LED turns off and on. The resistance changes as the amount of light strikes the photoresistor. As the light decreases, the resistance increases. The increased resistance lowers the voltage at the base of the NPN transistor (Q2).
Project #259 Oscillator 0.5 - 30Hz OBJECTIVE: To build a 0.5Hz - 30Hz oscillator that will light an LED. Set the adjustable resistor (RV) to the bottom position and then turn the slide switch (S1) on. The LED (D1) will start flashing at a frequency of 0.5Hz (once every two seconds). Slowly adjust the adjustable resistor and the LED flashes faster. As the frequency increases, the LED flashes faster. Eventually, the LED flashes so fast, it looks like it is on all of the time.
Project #262 Motor Rotation OBJECTIVE: To show how voltage polarity affects a DC motor. Place the fan onto the motor (M1). Press the press switch (S2). The fan rotates clockwise. When you connect the positive (+) side of the battery (B1) to the positive (+) side of the motor, it spins clockwise. Release the press switch and turn on the slide switch (S1). Now the fan spins the other way. The positive (+) side of the battery is connected to the negative (–) side of the motor.
Project #265 High Pitch Bell OBJECTIVE: To build a high pitch bell. Build the circuit shown and press the press switch (S2). The circuit starts to oscillate. This generates the sound of a high pitch bell. Project #266 Steamboat Whistle OBJECTIVE: To build a steamboat whistle. Using the circuit in project #265, connect the 0.02μF capacitor (C1) across the whistle chip (WC). Press the press switch (S2). The circuit now generates the sound of a steamboat.
Project #269 Noise-Activated Burglar Alarm OBJECTIVE: To build a noise activated alarm. Turn the slide switch (S1) on and wait for the sound to stop. Place the circuit into a room you want guarded. If a thief comes into the room and makes a loud noise, the speaker (SP) will sound again. If you find that the sound does not turn off, then vibrations created by the speaker may be activating the whistle chip.
Project #272 Photoresistor Control OBJECTIVE: To use a photoresistor to control the brightness of an LED. In this circuit, the brightness of the LED (D1) depends on how much light shines directly on the photoresistor (RP). If the photoresistor were held next to a flashlight or other bright light, then the LED would be very bright. The resistance of the photoresistor decreases as more light shines on it.
Project #274 Pressure Alarm OBJECTIVE: To build a pressure alarm circuit. Connect two jumper wires to the whistle chip (WC) as shown. Set the control of the adjustable resistor (RV) to the far left and turn on the switch. There is no sound from the speaker (SP) and the LED (D1) is off. Tap the center of the whistle chip. The speaker sounds and the LED lights. The whistle chip has a piezocrystal between the two metal plates. The sound causes the plates to vibrate and produce a small voltage.
Project #276 LED Fan Rotation Indicator OBJECTIVE: To build an LED fan rotation indicator. Do not place the fan onto the motor (M1). Turn the slide switch (S1) on. The motor rotates clockwise, and the green LED (D2) lights. When you connect the positive (+) side of the battery (B1) to the positive (+) side of the motor, it spins clockwise. Turn the slide switch off and press the press switch (S2). Now the fan spins the other way and the red LED (D1) lights.
Project #278 Sound Mixer OBJECTIVE: To connect two sound IC’s together. In the circuit, the outputs from the alarm (U2) and music (U1) IC’s are connected together. The sounds from both IC’s are played at the same time. Project #279 Sound Mixer Fan Driver OBJECTIVE: To connect two sound IC’s together to drive two LED’s and a motor. Build the circuit shown on the left. Place the fan onto the motor (M1). In the circuit, the alarm IC (U2) and the music IC (U1) are connected together.
Project #280 Electric Fan Stopped by Light OBJECTIVE: To show how light can control a motor. Turn on the slide switch (S1) and set the adjustable resistor (RV) control so the motor (M1) just starts spinning. Slowly cover the photoresistor (RP) and the motor spins faster. By placing more light over the photoresistor, the motor slows. The fan will not move on most settings of the resistor, because the resistance is too high to overcome friction in the motor.
Project #282 Start-Stop Delay OBJECTIVE: To start and stop a motor with light. Place the fan on the motor (M1). Turn on the slide switch (S1), the motor starts spinning. As you move your hand over the photoresistor, (RP) the motor slows. Now place a finger on top of the photoresistor to block the light. The motor slows down. In a few seconds the motor speeds up again. The fan will not move on most settings of the resistor, because the resistance is too high to overcome friction in the motor.
Project #284 Mail Notifying Electronic Bell OBJECTIVE: To build a circuit to indicate if you have mail by sounding a tone. Turn on the slide switch (S1). If there is enough light on the photoresistor (RP), the speaker (SP) will not make any sound. Place your finger over the photoresistor and now the speaker sounds. The sound will stay on until you turn off the slide switch. A simple mail notifying system can be made using this circuit.
Project #288 AM Radio with Transistors OBJECTIVE: To build a complete, working AM radio with transistor output. When you turn on the slide switch (S1), the integrated circuit (U5) should amplify and detect the AM radio waves. Tune the variable capacitor (CV) to the desirable station. Set the adjustable resistor (RV) for the best sound. The two transistors (Q1 & Q2) drive the speaker (SP) to complete the radio. The radio will not be very loud.
Project #290 Music Amplifier OBJECTIVE: circuit. To amplify sounds from the music integrated Build the circuit and turn on the slide switch (S1). You will hear loud music, since the sound from the music IC (U1) is amplified by the power amplifier IC (U4). All radios and stereos use a power amplifier. Project #291 Delayed Action Lamp Project #292 OBJECTIVE: To build a lamp that stays on for a while. Delayed Action Fan OBJECTIVE: To build a fan that stays on for a while.
Project #293 Police Siren Amplifier OBJECTIVE: circuit. To amplify sounds from the music integrated Build the circuit and turn on the slide switch (S1). You will hear a very loud siren, since the sound from the alarm IC (U2) is amplified by the power amplifier IC (U4). Sirens on police cars use a similar circuit, with an IC to create the sound and a power amplifier to make it very loud. Project #294 Lasting Doorbell OBJECTIVE: To build a doorbell that stays on for a while.
Project #296 Quieting a Motor OBJECTIVE: To show how capacitors can filter out electrical disturbances. Place the fan on the motor (M1) and turn off the slide switch (S1). Press the press switch (S2) and listen to the motor. As the motor shaft spins around it connects/ disconnects several sets of electrical contacts. As these contacts are switched, an electrical disturbance is created, which the speaker converts into sound. Turn on the slide switch and push the press switch again.
Project #299 Blowing Space War Sounds OBJECTIVE: To change space war sounds by blowing. Turn on the slide switch (S1) and you will hear explosion sounds and the lamp is on or flashing. Blow into the microphone (X1) and you can change the sound pattern. Project #300 Adjustable Time Delay Lamp Project #301 OBJECTIVE: To build a lamp that stays on for a while. Adjustable Time Delay Fan OBJECTIVE: To build a fan that stays on for a while. Turn on the slide switch (S1) press the press switch (S2).
Project #302 Adjustable Project #303 Time Delay Adjustable Time Delay Fan (II) Lamp (II) OBJECTIVE: To build a lamp that stays on for a while. Be sure to use the 2.5V lamp (L1) for this circuit. Turn on the switch and press the press switch (S2). The lamp stays on for a few seconds after you release the press switch. You can change the delay time with the adjustable resistor (RV). Project #304 Watch Light OBJECTIVE: To build a lamp that stays on for a while.
OTHER SNAP CIRCUITS® PROJECTS! For a listing of local toy retailers who carry Snap Circuits®, please visit www.elenco.com or call us toll-free at (800) 533-2441. For Snap Circuits® upgrade kits, accessories, additional parts, and more information about your parts, please visit www.snapcircuits.net.
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