10. The speaker is driven by transistors ________ and ________. 9. The frequency of oscillation of Q3 and Q4 is about ____________ cycles per second. 8. Capacitor C3 causes transistor Q3 and Q4 to _____________. 7. The charge to discharged ratio on C1 is ___________. 6. Capacitor C1 charges through resistor _______ and discharges through resistor __________. 5. When the power is first turned on, the voltage across C1 is ___________. 4. When the power is first turned on, the voltage at the base of Q2 is ___________. 3. The high frequency oscillations are generated by transistors __________ and __________. 2. The low frequency oscillations are generated by transistors __________ and __________. 1. The Whooper Alarm has ___________ oscillators. QUIZ 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Website: www.elenco.com e-mail: firstname.lastname@example.org Elenco® Electronics, Inc. Answers: 1) two; 2) Q1, Q2; 3) Q3, Q4; 4) 5.4V; 5) zero; 6) R2, R8; 7) 22:1; 8) oscillate; 9) 1,000; 10) Q4, Q5 Revised 2009 REV-F No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher. Copyright © 2009, 1989 by Elenco® Electronics, Inc. All rights reserved. ® Elenco Electronics, Inc. Instruction & Assembly Manual MODEL K-24 WHOOPER ALARM KIT 753224 Symbol Q1, Q3, Q4 Q2 Q5 Symbol Qty. r3 r1 r1 Qty. r1 r1 r1 Battery Snap Transistor • Insert battery with correct polarity. • Use only 9V type (not included). Qty. r1 r1 r2 Symbol B1 SPK1 -1- Speaker Switch Description Battery Snap 9V Speaker 8Ω Wire 4” Blue not be Part # 590098 590102 814620 Part # 323904 323906 326531 Part # 244780 281044 Part # 131000 141000 142200 146800 151500 152200 152700 • Batteries are harmful if swallowed, so keep away from small children. • Non-rechargeable batteries should recharged. • Remove battery when it is used up. Discap Electrolytic Capacitors • Never throw battery in a fire or attempt to open it. • Do not short circuit the battery terminals. BATTERIES Part # 518000 541102 551124 MISCELLANEOUS Description Transistor Transistor Transistor SEMICONDUCTORS Description Discap Electrolytic CAPACITORS Color Code brown-black-brown-gold brown-black-red-gold red-red-red-gold blue-gray-red-gold brown-green-orange-gold red-red-orange-gold red-violet-orange-gold PARTS IDENTIFICATION Description PC Board Switch Slide SPDT Solder Roll 24” Value 2N3904 2N3906 MPS6531 Value .047μF (473) 100μF Description 100Ω 5% 1/4W 1kΩ 5% 1/4W 2.2kΩ 5% 1/4W 6.8kΩ 5% 1/4W 15kΩ 5% 1/4W 22kΩ 5% 1/4W 27kΩ 5% 1/4W Resistor Symbol C2, C3 C1, C4 Qty. r2 r2 S1 Symbol R8 R3, R6 R2 R5 R1, R9 R4 R7 Qty. r1 r2 r1 r1 r2 r1 r1 RESISTORS Consult your instructor or contact Elenco® Electronics if you have any problems. DO NOT contact your place of purchase as they will not be able to help you. If you are a student, and any parts are missing or damaged, please see instructor or bookstore. If you purchased this Whooper Alarm Kit from a distributor, catalog, etc., please contact Elenco® Electronics (address/phone/e-mail 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. SCHEMATIC DIAGRAM -6- 5. Read the circuit operation lesson manual to familiarize yourself with the workings of the circuit. 4. Use a fresh 9 volt battery. 3. Be sure that transistors Q1 - Q5 have been installed correctly. The flat side should be in the same direction as shown on the top legend. 2. Be sure that the electrolytic capacitors C1 and C4 have been installed correctly. These capacitors have polarity, the negative and positive leads must be in the correct holes, as shown on the top legend of the PC board. 1. Be sure that all of the components have been mounted in their correct places. COMPONENT CHECK d) Have any solder bridges formed? A solder bridge may occur if you accidentally touch an adjacent foil by using too much solder or by dragging the soldering iron across adjacent foils. Break the bridge with your soldering iron. c) Solder should flow into a smooth puddle rather than a round ball. Resolder any connection that has formed into a ball. b) All solder connections should be shiny. Resolder any that are not. a) Tug slightly on all parts to make sure that they are indeed soldered. 1. One of the most frequently occurring problems is poor solder connections. TROUBLESHOOTING PARTS LIST R5 - 6.8kΩ 5% 1/4W Resistor (blue-gray-red-gold) C3 - .047μF (473) Discap B1 - Battery Snap (see Figure D) R2 - 2.2kΩ 5% 1/4W Resistor (red-red-red-gold) Q4 - 2N3904 Transistor (see Figure A) C2 - .047μF (473) Discap PC board Figure D Insert the red and black wires through the hole in the PC board as shown. Insert the red wire into the positive (+) hole and the black wire into the negative hole. Solder and cut off the excess leads. Flat -5- Red Speaker lugs Battery snap Black 4” Wires Cut two 4” wires and strip 1/8” of insulation off of both wires. Solder a wire to each lug of the speaker and then insert the other end of the wires through the hole in the PC board, and solder in the place shown on the top legend. Mount the transistor with the flat side in the same direction as shown on the PC board. Solder and cut off the excess leads. PC board Figure B Figure A C1 - 100μF Electrolytic Cap. (see Figure C) R7 - 27kΩ 5% 1/4W Resistor (red-violet-orange-gold) Polarity marking Foil Side of PC Board Marking on legend side of PC board If the capacitor is connected with incorrect polarity, it may heat up and either leak, or cause the capacitor to explode. Warning: Electrolytic capacitors have polarity. Be sure to mount them with the negative (–) lead (marked on side) in the correct hole. Figure C Q2 - 2N3906 Transistor (see Figure A) R4 - 22kΩ 5% 1/4W Resistor (red-red-orange-gold) C4 - 100μF Electrolytic Cap. (see Figure C) R9 - 15kΩ 5% 1/4W Resistor (brown-green-orange-gold) R8 - 100Ω 5% 1/4W Resistor (brown-black-brown-gold) S1 - Slide Switch Q5 - MPS 6531 Transistor (see Figure A) R1 - 15kΩ 5% 1/4W Resistor (brown-green-orange-gold) Q1 - 2N3904 Transistor (see Figure A) SPK - Speaker (see Figure B) R6 - 1kΩ 5% 1/4W Resistor (brown-black-red-gold) R3 - 1kΩ 5% 1/4W Resistor (brown-black-red-gold) Q3 - 2N3904 Transistor (see Figure A) ASSEMBLE COMPONENTS TO THE PC BOARD 2 3 4 5 6 7 8 9 1 Digit 0 Color Black Brown Red Orange Yellow Green Blue Violet Gray White Digit 0 1 2 3 4 5 6 7 8 9 BAND 2 2nd Digit Color Black Brown Red Orange Yellow Green Blue Silver Gold Multiplier 1 10 100 1,000 10,000 100,000 1,000,000 0.01 0.1 Multiplier Color Silver Gold Brown Red Orange Green Blue Violet Tolerance ±10% ±5% ±1% ±2% ±3% ±0.5% ±0.25% ±0.1% Resistance Tolerance 1 2 Multiplier BANDS Tolerance Polarity Marking Abbreviation p n μ m – k M Means pico nano micro milli unit kilo mega 100V 10 1 2 100 -2- Or 10-12 10-9 10-6 10-3 100 103 106 5 0.1 9 = 1 micro unit = 1 nano unit Note: The letter “R” may be used at times to signify a decimal point; as in 3R3 = 3.3 = 1 kilo unit 5. 1,000 units = 1 mega unit = 1 unit 4. 1,000 milli units 6. 1,000 kilo units 8 10k 100k .01 4 3. 1,000 micro units = 1 milli unit 2. 1,000 nano units 1. 1,000 pico units The letter K indicates a tolerance of +10% The letter J indicates a tolerance of +5% * The letter M indicates a tolerance of +20% Multiply Unit By .000000000001 .000000001 .000001 .001 1 1,000 1,000,000 1k 3 Maximum Working Voltage Tolerance* Multiplier 1 0 The value is 10 x 1,000 = 10,000pF or .01μF 100V First Digit 103K Multiply By For the No. Second Digit Multiplier METRIC UNITS AND CONVERSIONS If the capacitor is connected with incorrect polarity, it may heat up and either leak, or cause the capacitor to explode. Warning: Electrolytic capacitors have a positive and a negative electrode. The negative lead is indicated on the packaging by a stripe with minus signs and possibly arrowheads. Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or μF (microfarads). Most capacitors will have their actual value printed on them. Some capacitors may have their value printed in the following manner. The maximum operating voltage may also be printed on the capacitor. IDENTIFYING CAPACITOR VALUES Color Black Brown Red Orange Yellow Green Blue Violet Gray White BAND 1 1st Digit Use the following information as a guide in properly identifying the value of resistors. IDENTIFYING RESISTOR VALUES Figure 3 -3- The circuit of the high frequency oscillator is shown in Figure 3. Transistors Q3 and Q4 are wired as amplifier stages. The bias for these amplifiers are controlled by the sawtooth of Figure 2. These amplifiers normally would amplify the low frequency pulses, except for the addition of capacitor C3. This capacitor takes the output of Q4 and feeds it in phase to the input of Q3. This causes the circuit to oscillate. The frequency of oscillation is controlled by the RC time constants of C3 and R6. The frequency of oscillation is about 1,000 cycles per second. This frequency is modulated with the low frequency oscillations to produce the Whooper Alarm sounds. Transistor Q5 further amplifies the signals and drives the speaker. HIGH FREQUENCY OSCILLATOR A current is flowing in resistor R2 charging capacitor C1. When the voltage across C1 reaches 6V, transistor Q2 starts sending a current in the collector of Q1. The current in the collector of Q1 is mulitplied by the gain of transistor Q1 and this rapidly turns on transistor Q2. Capacitor C1 quickly discharges through resistor R8 as shown in Figure 2. Note that C1 charges through a 2200Ω resistor R2, but discharges through a 100Ω resistor R8. Thus, the charge to discharge ratio is 22:1. When C1 is discharged, Q1 and Q2 turn off and the whole cycle repeats itself. Figure 1 shows the circuits of the low frequency oscillator. When the power is first applied to this circuit, transistors Q1 and Q2 will not conduct. This is because the base of transistor Q2 is about 5.4V while the emitter is at zero volts. CIRCUIT OPERATION The Whooper Alarm circuit consists of two oscillators, a low frequency oscillator which drives a higher frequency unit at a predetermined rate. The high frequency oscillator drives an output transistor which powers the speaker. The Whooper Alarm puts out a wavering sound that is sure to startle an intruder. It can be used independently or as an accessory to the Burglar Alarm Kit K-23. MINIATURE RADIO TRANSMITTER Volts Figure 2 Time Figure 1 4. Here is what a good solder connection looks like. 3. Allow the solder to flow around the connection. Then, remove the solder and the iron and let the connection cool. The solder should have flowed smoothly and not lump around the wire lead. 2. Apply a small amount of solder to the iron tip. This allows the heat to leave the iron and onto the foil. Immediately apply solder to the opposite side of the connection, away from the iron. Allow the heated component and the circuit foil to melt the solder. 1. Solder all components from the copper foil side only. Push the soldering iron tip against both the lead and the circuit board foil. Foil Solder Foil Solder Foil Soldering Iron Soldering Iron Circuit Board Component Lead Soldering Iron A good solder connection should be bright, shiny, smooth, and uniformly flowed over all surfaces. What Good Soldering Looks Like • Use the correct tip size for best heat transfer. The conical tip is the most commonly used. • Keep the iron tinned at all times. Use these procedures to increase the life of your soldering iron tip when using lead-free solder: Lead-free solder is different from lead solder: It has a higher melting point than lead solder, so you need higher temperature for the solder to flow properly. Recommended tip temperature is approximately 700OF; higher temperatures improve solder flow but accelerate tip decay. An increase in soldering time may be required to achieve good results. Soldering iron tips wear out faster since lead-free solders are more corrosive and the higher soldering temperatures accelerate corrosion, so proper tip care is important. The solder joint finish will look slightly duller with lead-free solders. For many years leaded solder was the most common type of solder used by the electronics industry, but it is now being replaced by leadfree solder for health reasons. This kit contains lead-free solder, which contains 99.3% tin, 0.7% copper, and has a rosin-flux core. Solder The most important factor in assembling your K-24 Whooper Alarm Kit is good soldering techniques. Using the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is recommended. The tip of the iron must be kept clean at all times and well tinned. Introduction CONSTRUCTION -4- ' 4. Solder bridges - occur when solder runs between circuit paths and creates a short circuit. This is usually caused by using too much solder. To correct this, simply drag your soldering iron across the solder bridge as shown. 3. Excessive solder - could make connections that you did not intend to between adjacent foil areas or terminals. 2. Insufficient solder - let the solder flow over the connection until it is covered. Use just enough solder to cover the connection. 1. Insufficient heat - the solder will not flow onto the lead as shown. Foil Solder Gap Drag Soldering Iron Component Lead Solder Soldering iron positioned incorrectly. Rosin Types of Poor Soldering Connections DO NOT USE ACID CORE SOLDER! In all of the following assembly steps, the components must be installed on the top side of the PC board unless otherwise indicated. The top legend shows where each component goes. The leads pass through the corresponding holes in the board and are soldered on the foil side. Use only rosin core solder. Assemble Components • Do not hold solder in your mouth. Solder is a toxic substance. Wash hands thoroughly after handling solder. • Locate soldering iron in an area where you do not have to go around it or reach over it. Keep it in a safe area away from the reach of children. • Be sure there is adequate ventilation when soldering. • Always wear safety glasses or safety goggles to protect your eyes when working with tools or soldering iron, and during all phases of testing. Safety Procedures • Tips should be cleaned frequently to remove oxidation before it becomes impossible to remove. Use Dry Tip Cleaner (Elenco® #SH-1025) or Tip Cleaner (Elenco® #TTC1). If you use a sponge to clean your tip, then use distilled water (tap water has impurities that accelerate corrosion). • Turn off iron when not in use or reduce temperature setting when using a soldering station.
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