Related Manuals for Elenco Electronics EP-50
Summary of Contents for Elenco Electronics EP-50
- Page 1 ELECTRONIC PLAYGROUND and LEARNING CENTER MODEL EP-50 Elenco Electronics, Inc. Wheeling, IL, USA Copyright © 1998 Elenco Electronics, Inc. 753057...
-
Page 2: Table Of Contents
TABLE OF CONTENTS Definition of Terms Answers to Quizzes Introduction to Basic Components Experiment #1: The Light Bulb More About Resistors Experiment #2: Brightness Control Experiment #3: Resistors in Series Experiment #4: Parallel Pipes Experiment #4B: Comparison of Parallel Currents 14 Experiment #5: Combined Circuit Experiment #6: Water Detector Introduction to Capacitors... -
Page 3: Definition Of Terms
DEFINITION OF TERMS (Most of these will be introduced and explained during the experiments). Common alternating current. Alternating Current A current that is constantly changing. Amplitude amplitude of the radio signal is varied information being sent. Shortened name for ampere. Ampere (A) The unit of measure for electric current. - Page 4 Electron A sub-atomic particle that has an electrical charge. Electronics The science of electricity and its applications. Emitter The output of an NPN bipolar junction transistor. Encode To put a message into a format which is easier to transmit. Farad, (F) unit capacitance.
- Page 5 Pico- (p) A prefix used in the metric system. It means a millionth of a millionth (0.000,000,000,001) of something. Pitch The musical term for frequency. Printed Circuit Board A board used for mounting electrical components. Components are connected using metal traces “printed” on the board instead of wires.
-
Page 6: Introduction To Basic Components
INTRODUCTION TO BASIC COMPONENTS Welcome to the exciting world of Electronics! Before starting the first experiment, let’s learn about some of the basic electronic components. Electricity is a flow of sub- atomic (very, very, very, small) particles, called electrons. The electrons move from atom to atom when an electrical charge is applied across the material. - Page 7 The Resistor: Why is the water pipe that goes to your kitchen faucet smaller than the one that comes to your house from the water company? And why is it much smaller than the main water line that supplies water to your entire town? Because you don’t need so much water.
-
Page 8: Experiment #1: The Light Bulb
EXPERIMENT #1: The Light Bulb First, you need a 9V battery (alkaline is best). Fold out the the battery holder cutouts and snap the battery into its clip. Always remove the battery from its clip if you won’t be using your Playground for a while. Your Electronic Playground consists of electronic parts connected to springs and mounted on a cardboard panel. - Page 9 Press the switch (next to springs 55 and 56) and the LED (light emitting diode) lights up, and turns off when you release the switch. The LED converts electrical energy into light, like the light bulbs in your home. You can also think of an LED as being like a simple water meter, since as the electric current increases in a wire the LED becomes brighter.
-
Page 10: More About Resistors
MORE ABOUT RESISTORS Ohm’s Law: You just observed that when you have less resistance in the circuit, more current flows (making the LED brighter). The relationship between voltage, current, and resistance is known as Ohm’s Law (after George Ohm who discovered it in 1828): Voltage Current = Resistance... -
Page 11: Experiment #2: Brightness Control
EXPERIMENT #2: The Brightness Control Connect the wires according to the Wiring Checklist. Press the switch and the LED lights up. Now hold the switch closed with one hand and turn the dial on the variable resistor with the other. When the dial setting is high, the resistance in the circuit is low and the LED is bright because a large current flows. -
Page 12: Experiment #3: Resistors In Series
EXPERIMENT #3: Resistors in Series Connect the wires according to the Wiring Checklist and press the switch. The LED is on but is very dim (this will be easier to see if you wrap your hand near the LED to keep the room lights from shining on it). -
Page 13: Experiment #4: Parallel Pipes
EXPERIMENT #4: Parallel Pipes Connect the wires according to the Wiring Checklist. Take a look at the schematic. There is a low 3.3KW resistor and a high 100KW resistor in parallel (connected between the same points in the circuit). How bright do you think the LED will be? Press the switch and see if you are right. -
Page 14: Experiment #4B: Comparison Of Parallel Currents
There is an even easier way to explain this: EXPERIMENT #4B: Comparison of Parallel Currents Since we have two resistors in parallel and a second LED that is not being used, let’s modify the circuit to match the schematic below. It’s basically the same circuit but instead of just parallel resistors there are parallel resistor- LED circuits. -
Page 15: Experiment #5: Combined Circuit
EXPERIMENT #5: Combined Circuit Let’s combine everything we’ve done so far. Connect the wires according to the Wiring Checklist. Before pressing the switch, take a look at the schematic and think about what will happen as you turn the dial on the variable resistor (we’ll abbreviate this to VR). -
Page 16: Experiment #6: Water Detector
EXPERIMENT #6: Water Detector You’ve seen how electricity flows through copper wires easily and how carbon resists the flow. How well does water pass electricity? Let’s find out. Connect the wires according to the Wiring Checklist and take a look at the schematic. There isn’t a switch this time, so just disconnect one of the wires if you want to turn the circuit off. -
Page 17: Introduction To Capacitors
INTRODUCTION TO CAPACITORS Capacitors: Capacitors are electrical components that can store electrical pressure (voltage) for periods of time. When a capacitor has a difference in voltage (electrical pressure) across it, it is said to be charged. A capacitor is charged by having a one-way current flow through it for a short period of time. - Page 18 Similarly, capacitors are described by their capacity for holding electric charge, called their Capacitance, and their ability to withstand electric pressure (voltage) without damage. Although there are many different types of capacitors made using many different materials, their basic construction is the same. connect to two or more metal plates that are separated by high resistance materials called dielectrics.
-
Page 19: Experiment #7: Slow Light Bulb
EXPERIMENT #7: Slow Light Bulb Connect the wires according to the Wiring Checklist and press the switch several times. You can see it takes time to charge and discharge the large capacitor because the LED lights up and goes dim slowly. Replace the 3.3KW resistor with the 1KW resistor;... -
Page 20: Experiment #8: Small Dominates Large
EXPERIMENT #8: Small Dominates Large - Capacitors in Series Take a look at the schematic, it is almost the same circuit as the last experiment except that now there are two capacitors in series. What do you think will happen? Connect the wires according to the Wiring Checklist and press the switch several times to see if you are right. -
Page 21: Experiment #9: Large Dominates Small
EXPERIMENT #9: Large Dominates Small - Capacitors in Parallel Now you have capacitors in parallel, and you can probably predict what will happen. If not, just think about the last experiment and about how resistors in parallel combine, or think in terms of the water diagram again. Connect the wires according to the Wiring Checklist and press the switch several times to see. -
Page 22: Experiment #10: Make Your Own Battery
EXPERIMENT #10: Make Your Own Battery Connect the wires according to the Wiring Checklist, noting that there is no switch and a long wire with one end connected to the 100mF capacitor and the other end unconnected. At this time no current will flow because nothing is connected to the battery. -
Page 23: Test Your Knowledge #1
TEST YOUR KNOWLEDGE #1 1. __________ are the particles that flow between atoms as part of an electric current. 2. A __________ circuit occurs when wires or components from different parts of the circuit accidentally connect. 3. A __________ produces electricity using a chemical reaction. -
Page 24: Experiment #11: One-Way Current
EXPERIMENT #11: One-way Current Connect the wires according to the Wiring Checklist and press the switch, the LED lights up. The diode’s turn-on voltage of 0.7V is easily exceeded and the diode has little effect on the circuit. Now reverse the wires to the diode and try again, nothing happens. -
Page 25: Experiment #12: One-Way Lightbulbs
EXPERIMENT #12: One-way Lightbulbs Diodes made of Gallium Arsenide need a higher voltage across them to turn on, usually about 1.5V This turn-on energy is so high that light is generated when current flows through the diode. These diodes are the light emitting diodes that you have been using. -
Page 26: Introduction To Transistors
INTRODUCTION TO TRANSISTORS The Transistor: The transistor was first developed in 1949 at Bell Telephone Laboratories, the name being derived from “transfer resistor”. It has since transformed the world. Did you ever hear of something called a vacuum tube? They are large and can be found in old electronic equipment and in museums. -
Page 27: Experiment #13: The Electronic Switch
EXPERIMENT #13: The Electronic Switch Connect the wires according to the Wiring Checklist. Although there is a closed circuit with the battery, 1KW, LED, and transistor, no current will flow since the transistor is acting like an open circuit (with no base current the lever arm remains shut). -
Page 28: Experiment #14: The Current Amplifier
EXPERIMENT #14: The Current Amplifier Connect the wires according to the Wiring Checklist and press the switch. LED 1 in the collector path is brighter than LED 2 in the base path because the base current is amplified by the transistor. The current gain of a transistor varies anywhere from 10 to 1000 depending on the type of transistor, the ones in your Electronic... -
Page 29: Experiment #15: The Substitute
EXPERIMENT #15: The Substitute Look again at the water pipe analogy for the transistor, the lever pivot: Wiring Checklist: o 27-to-56 o 55-to-16-to-15 o 17-to-42 o 43-to-3 o 4-to-26 What would happen if the base and collector were connected together? Once there is enough pressure to overcome the spring in check valve DE (0.7V) there would be only slight resistance and no current gain. -
Page 30: Experiment #16: Standard Transistor Biasing Circuit
EXPERIMENT #16: Standard Transistor Biasing Circuit Connect the wires according to the Wiring Checklist and press the switch while turning the variable resistor from right to left (from 0W to 50KW). The 100KW and variable 50KW are a voltage divider that sets the voltage at the transistor base. -
Page 31: Experiment #17: Very Slow Light Bulb
EXPERIMENT #17: Very Slow Light Bulb Connect the wires according to the Wiring Checklist and press the switch, hold it down for several seconds. The LED will slowly light up. Release the switch and the LED will slowly go dark. When you first press the switch all of the current flowing through the 100KW resistor goes to charge up the capacitor, the transistor and LED will be off. -
Page 32: Experiment #18: The Darlington
EXPERIMENT #18: The Darlington This circuit is very similar to the last one. Connect the wires according to the Wiring Checklist and press the switch, hold it down for several seconds. The LED will slowly light up. Release the switch and the LED stays lit. Take a look at the schematic. -
Page 33: Experiment #19: The Finger Touch Lamp
EXPERIMENT #19: The Finger Touch Lamp Take a look at the schematic. You’re probably wondering how it can work, since nothing is connected to the transistor base. It can’t, but there is another component that isn’t shown in the schematic. That component is you. Connect the wires according to the Wiring Checklist. -
Page 34: Experiment #20: The Battery Immunizer
EXPERIMENT #20: Battery Immunizer Connect the wires according to the Wiring Checklist and schematic. Note that the collectors of NPN2 and NPN3 are not connected although their wires cross over each other in the schematic. Connect the loose wire from spring 43 (3.3KW) to spring 16 (NPN1 collector, or 9V);... -
Page 35: Experiment #21: The Voltmeter
EXPERIMENT #21: The Voltmeter Make sure you have a strong 9V battery for this experiment. Connect the wires according to the Wiring Checklist, connecting the wire to the battery last since this will turn on the circuit. And be sure to disconnect this battery wire when you’re not using the circuit to avoid draining the battery. -
Page 36: Experiment #22: 1.5 Volt Battery Tester
EXPERIMENT #22: 1.5 Volt Battery Tester Make sure you have a strong 9V battery for this experiment. Connect the wires according to the Wiring Checklist, connecting the wire to the battery last since this will turn on the circuit. And be sure to disconnect this battery wire when you’re not using the circuit to avoid draining the battery. -
Page 37: Experiment #23: 9 Volt Battery Tester
EXPERIMENT #23: 9 Volt Battery Tester Make sure you have a strong 9V battery for this experiment. Connect the wires according to the Wiring Checklist, connecting the wire to the battery last since this will turn on the circuit. And be sure to disconnect this battery wire when you’re not using the circuit to avoid draining the battery. -
Page 38: Experiment #24: The Anti-Capacitor
EXPERIMENT #24: The Anti-Capacitor Recall that capacitors blocked direct current (DC) but passed alternating current (AC). Experiment 7 again and remember that it took time to light the LED because you had to charge the capacitor first; the capacitor passed the initial current surge through to ground (the negative side of the battery) but blocked the current once it stabilized, forcing it to go through the LED. - Page 39 NOTES -39-...
- Page 40 The Inductor: The inductor can best be described as electrical momentum (momentum is the power a moving object has). In our water pipe analogy the inductor can be thought of as a very long hose wrapped around itself many times as shown here: Plunger Since the hose is long it contains many gallons of water.
-
Page 41: Test Your Knowledge #2
If you wrap two wires from different circuits around different ends of an iron bar then a current flowing through the wire from the first circuit will magnetically create a current in the wire from the second circuit! If the second coil has twice as many turns (more magnetic linkage) as the first coil then the second coil will have twice the voltage but half the current as the first coil. -
Page 42: Experiment #25: The Magnetic Bridge
EXPERIMENT #25: The Magnetic Bridge Connect the wires according to the Wiring Checklist. You are using the antenna for the first time here but only as a low-value resistor (about 10W); it has other properties that will be explained in later experiemnts. Press the switch several times. -
Page 43: Experiment #26: The Lighthouse
EXPERIMENT #26: The Lighthouse Connect the wires according to the Wiring Checklist. Notice that the transformer is being used as two coils (inductors) here. Also notice that transformer springs 23 and 24 are not connected although their wires cross in the schematic. -
Page 44: Experiment #27: Electronic Sound
EXPERIMENT #27: Electronic Sound Now it’s time to make some noise. To do this we need a speaker. A speaker converts electrical energy into sound. It does this by using the energy of an AC electrical signal to create mechanical vibrations. These vibrations create variations in air pressure, called sound waves, which travel across the room. - Page 45 Schematic Wiring Checklist: o 27-to-56 o 55-to-24 o 25-to-19 o 20-to-26 o 18-to-43 o 5-to-21 o 6-to-22 o 42-to-31-to-33-to-35-to-37-to-44-to-46-to-53-to-51 o unconnected-to-23-to-unconnected (2 loose wires) Loose Wires -45-...
-
Page 46: Experiment #28: The Alarm
EXPERIMENT #28: The Alarm This circuit is unusual in that you turn it on by disconnecting a wire and turn it off by connecting the wire. Connect the wires according to the Wiring Checklist and schematic, including a long wire as the “trip” wire. Notice that there is no sound. -
Page 47: Experiment #29: Morse Code
EXPERIMENT #29: Morse Code The forerunner of today’s telephone system was the telegraph, which was widely used in the latter half of the 19th century. It only had two states – on or off (that is, transmitting or not transmitting), and could not send the range of frequencies contain in human voices or music. -
Page 48: Experiment #30: Siren
EXPERIMENT #30: Siren Connect the wires according to the Wiring Checklist and press the switch. It makes a siren sound. You saw earlier how you could change the frequency (pitch) of the oscillator by changing the oscillator’s resistance. Well this is basically the same oscillator circuit you’ve been using except that now we are electronically varying the oscillator’s resistance. -
Page 49: Experiment #31: Electronic Rain
EXPERIMENT #31: Electronic Rain Connect the wires according to the Wiring Checklist and press the switch. You hear a sound like raindrops. The variable resistor (VR) knob controls the rain, turn it to the right to make a drizzle and turn to the left to make the rain come pouring down. -
Page 50: Experiment #32: The Space Gun
EXPERIMENT #32: The Space Gun Connect the wires according to the Wiring Checklist and press the switch several times quickly. You hear a sound like a space gun in the movies. You can adjust the “gun” sound using the variable resistor. inconvenient to turn the VR knob while pressing the switch then just connect a wire across the switch. -
Page 51: Experiment #33: Electronic Noisemaker
EXPERIMENT #33: Electronic Noisemaker Connect the wires according to the Wiring Checklist, connecting the battery wire last since it will turn the circuit on. Press the switch several times quickly. Then turn the variable resistor knob to change the frequency of the sounds. -
Page 52: Experiment #34: Drawing Resistors
EXPERIMENT #34: Drawing Resistors You need some more parts to do this experiment, so you’re going to draw them. Take a pencil (No. 2 lead is best but other types will also work), SHARPEN IT, and fill in the 4 rectangles you see below. You will get better results if you place a hard, flat surface between this page and the rest of this booklet while you are drawing. -
Page 53: Experiment #35: Electronic Kazoo
EXPERIMENT #35: Electronic Kazoo Now it’s time to make your own music. This experiment will use the (almost) same circuit as the last one, so there is no schematic or Wiring Checklist. The only difference is that you will draw a new shape. A Kazoo is a musical instrument that is like a one-note flute, and you change the pitch (frequency) of the sound by moving a plunger up and down inside a tube. -
Page 54: Experiment #36: Electronic Keyboard
EXPERIMENT #36: Electronic Keyboard This experiment will use the (almost) same circuit as the last one, so there is no schematic or Wiring Checklist. The only difference is that you will draw a new shape. As before, take a pencil (No. 2 lead is best but other types will also work), SHARPEN IT again, and fill in the shape you see below. -
Page 55: Experiment #37: Fun With Water
EXPERIMENT #37: Fun with Water Connect the wires according to the Wiring Checklist. Initially the two loose wires are unconnected so there is no sound. Now touch each wire with fingers from different hands, you should hear a low-frequency sound. (Wetting your fingers with water or saliva will make better electrical contact). -
Page 56: Experiment #38: Transistor Radio
Today the air around us is full of radio transmissions for things such as music, television, cellular phones, aircraft navigation, communication with probes in outer space, radio-controlled toys, and thousands of other uses. The Federal Government makes sure that all of these uses operate on different frequencies so that they don’t interfere with each other. - Page 57 Schematic Wiring Checklist: o 28-to-9 o 8-to-15 o 7-to-29-to-32-to-51 o 52-to-42-to-16-to-10 o 33-to-31-to-17-to-20-to-48-to-26 o 11-to-30-to-50 o 49-to-34 o 53-to-35-to-18 o 19-to-23 o 5-to-21 o 6-to-22 o 43-to-54-to-27-to-25 -57-...
-
Page 58: Experiment #39: Radio Announcer
EXPERIMENT #39: Radio Announcer Now that you’ve built an AM receiver, how about building an AM transmitter? Ever wanted to be a radio announcer? You’re about to get your chance. Note: you need an AM radio for this experiment. Connect the wires according to the Wiring Checklist, connecting the battery wire last since this will turn on the circuit. -
Page 59: Experiment #40: Radio Jammer / Metal Detector
Wiring Checklist: o 25-to-26-to-47-to-45- to-41-to-39-to-33-to-35 o 28-to-9-to-16 o 17-to-38 o 7-to-30-to-29 o 15-to-31-to-44-to-48 o 8-to-32-to-42-to-19 o 20-to-40-to-34 o 18-to-51-to-46-to-36 o 37-to-23 o 5-to-21 o 6-to-22 o 43-to-52-to-50-to-27 EXPERIMENT #40: Radio Jammer / Metal Detector The circuit you have just built as an AM radio transmitter also has other applications. -
Page 60: Experiment #41: Blinking Lights
EXPERIMENT #41: Blinking Lights Take a look at the schematic. This circuit configuration is a type of oscillator called an astable multivibrator. What do you think it will do? Connect the wires according to the Wiring Checklist, noting that the transistor bases are not connected although their wires cross in the schematic. -
Page 61: Experiment #42: Noisy Blinker
EXPERIMENT #42: Noisy Blinker This circuit is similar to the last one. Connect the wires according to the Wiring Checklist (noting that the transistor bases are not connected although their wires cross in the schematic). Press the switch and hold it down. -
Page 62: Experiment #43: One Shot
EXPERIMENT #43: One-shot Do you know what this circuit will do? Connect the wires according to the Wiring Checklist (noting that the transistor bases are not connected although their wires cross in the schematic). Press the switch and release it. The LED is on for a few seconds and then goes out. -
Page 63: Experiment #44: Alarm With Shut-Off Timer
EXPERIMENT #44: Alarm with Shut-off Timer Let’s demonstrate a use for the timer circuit you just built by combining it with Experiment 28, the Alarm. Connect the wires according to the Wiring Checklist (noting that the transistor bases and transformer springs 23 and 24 are not connected although their wires cross in the schematic). -
Page 64: Experiment #45: The Flip-Flop
EXPERIMENT #45: The Flip-Flop This circuit is yet another variation of the basic multivibrator configuration. Connect the wires according to the Wiring Checklist. One LED will be on, the other off. Take the loose wire and touch it to the base of the transistor that is on (spring 15 or 18). -
Page 65: Experiment #46: Finger Touch Lamp With Memory
EXPERIMENT #46: Finger Touch Lamp with Memory Instead of using the wire to flip-flop the LED you may also use your fingers as you did in Experiment 19, the Finger Touch Lamp. We’ll use almost the same circuit here as in the last experiment. -
Page 66: Experiment #47: This Or That
EXPERIMENT #47: This OR That Now that you’re familiar with the flip-flop, let’s introduce some more digital circuits. Digital circuits are circuits that have only two states, such as high-voltage/low-voltage, on/off, yes/no, and true/false. according to Wiring Checklist. schematic, it is very simple. considered to be digital inputs, so connect them to either the battery spring 27 (9V, or HIGH) or leave them unconnected (this is the same as connecting them to 0V,... -
Page 67: Experiment #48: Neither This Nor That
EXPERIMENT #48: Neither This NOR That Now let’s add on to the previous circuit by adding the wires listed in the Wiring Checklist (these are in addition to the wires from Experiment 47, which you should still have assembled). Test four combinations of X and Y as before to... -
Page 68: Experiment #49: This And That
EXPERIMENT #49: This AND That Take a look at the schematic. Can you guess what kind of digital gate this is? We’ll use almost the same circuit here as in the last experiment. Remove the wire between springs 17 and 20, and the one between springs 16 and Add a wire between springs 17 and 19. -
Page 69: Experiment #50: Audio Nand, And
EXPERIMENT #50: Audio AND, NAND Using the LEDs for these truth tables probably seems a little boring. So let’s use an audio circuit to make a sound instead of turning on the LED. according to the Wiring Checklist. Can you tell which digital gate this circuit represents? Construct the truth table to find out. -
Page 70: Experiment #51: Logic Combination
EXPERIMENT #51: Logic Combination This last circuit is a combination of some of the other digital gates, and has 3 inputs. See if you can fill in the truth table by just looking at the schematic. Then connect the wires according to the Wiring Checklist, test all eight input combinations, and see if you were right. -
Page 71: Test Your Knowledge #3
TEST YOUR KNOWLEDGE #3 1. Adjusting the input to something based on what its output is doing is an example of __________. 2. A speaker converts electrical energy into __________ __________ variations, called sound waves. 3. An oscillator’s frequency __________ when you add resistance or capacitance. - Page 72 Elenco Electronics, Inc. 150 W. Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 http://www.elenco.com e-mail: elenco@elenco.com...