Selected page of Realistic Police Siren Kit
Realistic
POLICE
SIREN
KIT Runs on 6 to 12 volts. Drives any speaker. Two volume levels, 250 mW and
5 Watts. Easy to build two transistor circuit
teaches too! Kids love it!
Duplicates the upward and downward wail of a police siren. Great for
alarms, kids toys, bikes, go-karts, etc. Easily built by all ages!
Kit No. SM3
Realistic
POLICE
SIREN
KIT Runs on 6 to 12 volts. Drives any speaker. Two volume levels, 250 mW and
5 Watts. Easy to build two transistor circuit
teaches too! Kids love it!
Duplicates the upward and downward wail of a police siren. Great for
alarms, kids toys, bikes, go-karts, etc. Easily built by all ages!
Kit No. SM3
| SM3 2
SM3 2
INTRODUCTION TO THE SM3
The Ramsey SM3 will duplicate the sound of a police siren at a low (200 mw) or high (2 watts)
volume depending upon construction. Closing a pushbutton switch will cause the siren to "wail" up in
frequency and opening the button will cause it to "coast" down in frequency. You'll find plenty of uses
for the SM3. Kids love to play fire truck or ambulance on their bikes and wagons (Mom will appreciate
the low volume setting here!) and there are the obvious uses for alarms and alerting.
PARTS LIST FOR THE SM3 1 .01 or .02 uf disc capacitor [if .01: marked .01, 103, or 10 nF if .02: marked .02, 203, or
20 nF], (C1) 1 47 uF electrolytic capacitor, (C2) 2 47K resistor [yellow-violet-orange] (R1, R2) 1 1.5K resistor [brown-green-red] (R3) 1 PNP power transistor [green] (Q1) 1 NPN transistor [small black] (Q2) 1 SM3 PC board
INTRODUCTION TO THE SM3
The Ramsey SM3 will duplicate the sound of a police siren at a low (200 mw) or high (2 watt
| SM3 3
SM3 3
ASSEMBLING THE SM3
Installing and soldering six parts on a small PC board doesn't seem like much of a task, but there is
still the possibility for error, so follow our step-by-step directions and you'll be "wailing" real soon!
When we say to install a part, we mean: Carefully select the right part and insert it in the PC board. Gently press it fully down to the board surface. Solder the lead wires and don't be afraid of using too much heat for a good solid
connection. Clip or trim off the excess component lead wire.
SM3 parts layout
ASSEMBLING THE SM3
Installing and soldering six parts on a small PC board doesn't seem like much of a task, but there is
still the possibility for error, so follow our step-by-step directions and you'll be "wailing" real soon!
When we say to install a part, we mean: Carefully select the right part and insert it in the PC board. Gently press it fully down to the board surface. Solder the lead wires and don't be afraid of usi
| SM3 4
SM3 4 1. Orient the PC board as shown in the parts layout diagram with the five larger "pad" areas in a
row along the bottom. 2. Install C2, 47 uF. Observe polarity. Electrolytic capacitors have polarity markings. Generally,
capacitors will indicate the with a black stripe or arrow, while PC boards will usually show the hole. 3. Install R2, 47K (yellow-violet-orange). 4. Install C1, .01 or .02 uF. The holes for C2 are spaced far apart (you'll see why later) so just
stretch C1's leads to fit. 5. Install R1, 47K (yellow-violet-orange). 6. Install Q1, green power transistor. The metal back-side of Q1 must face as shown or your siren
won't work. 7. Install Q2, the black NPN transistor. Transistors always have to be installed in a certain way.
Be sure you position the flat side as shown. 8. Check your work especially the soldering. Let's hook it up! 1. Orient the PC board as shown in the parts layout diagram with the five larger "pad" areas in a
row along the bottom. 2.
| SM3 5
SM3 5
TESTING THE SM3
For testing your SM3 you'll need: A speaker with an impedance from 3 to 45 ohms. Any style will do, but a horn type will give the
most volume. Power source from 9 to 12 volts DC. A 9 volt battery will suffice for now. Pushbutton switch. A doorbell button works well, but simply touching two wires together will do. 1. Connect up the speaker to points 1 and 2. 2. Connect your pushbutton (or wires to touch) between point 4 and point 3 (the power
connection). 3. Connect power to point 3 and ground to point 5. 4. Depress the button and you'll hear the characteristic upward wail of the police siren.
TESTING THE SM3
For testing your SM3 you'll need: A speaker with an impedance from 3 to 45 ohms. Any style will do, but a horn type will give the
most volume. Power source from 9 to 12 volts DC. A 9 volt battery will suffice for now. Pushbutton switch. A doorbell button works well, but simply touching two wires together will do. 1. Connect up the speaker
| SM3 6
SM3 6
MODIFICATIONS HIGHER VOLUME: To increase the volume level, we add a resistor in series with C1 (that's why
we have the holes spaced farther apart!) Simply unsolder one end of C1 and connect to R3, 1.5K
(brown-green-red) as shown: YELPING SIREN: To make your siren sound like the yelping type (and get a tired pushbutton
finger, too!), change C2 from 47 uF to a smaller value such as 5 or 10 uF. Experiment with
different values for the right rate. You may find extra capacitors in old radios or other devices. If
need be, you can even buy them new at Radio Shack for about 69 a pair!
C1
TO HOLES
FOR C1
MODIFICATIONS HIGHER VOLUME: To increase the volume level, we add a resistor in series with C1 (that's why
we have the holes spaced farther apart!) Simply unsolder one end of C1 and connect to R3, 1.5K
(brown-green-red) as shown: YELPING SIREN: To make your siren sound like the yelping type (and get a tired pushbutton
finger, too!), change C2 from 47 uF t
| SM3 7
SM3 7 COUPLING THE AUDIO OUT TO A MICROPHONE INPUT: The SM3's audio can be easily
coupled into a microphone input for a PA system or radio. You only need to simulate a speaker
connected and add an audio coupling capacitor. Both parts are available at Radio Shack.
FINISHING TOUCHES
Your siren can be easily mounted in most any handy box or enclosure. A coffee or juice can makes
a dandy enclosure for speaker, battery, siren and pushbutton. Use your imagination, and see how
much use and fun you can get for such a small kit investment! We hope you enjoyed this entry level
Ramsey kit. Our catalog is loaded with lots of fun kits that you can build, from FM Stereo
Transmitters to complete Two-Way Ham Radio Transceivers. Call or write for a catalog today! COUPLING THE AUDIO OUT TO A MICROPHONE INPUT: The SM3's audio can be easily
coupled into a microphone input for a PA system or radio. You only need to simulate a speaker
connected and add an audio coupling capacitor
| SM3 8
SM3 8
The Ramsey Kit Warranty
Please read carefully BEFORE assembling your kit. All Ramsey kits will work if assembled properly. The very fact that your kit includes this new
manual is your assurance that a team of knowledgeable people have field-tested several "copies" of this kit straight from the Ramsey inventory. If you
need help, please read through your manual carefully, all information required to properly build and test your kit is contained within the pages!
1. DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit, Before you conclude that a part may be bad, thoroughly check your
work. All our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety (90) days from the date of purchase.
Defective parts will be replaced promptly at our expense. If you suspect any part to be defective, please mail it to our factory for testing and
replacement. Please send only the defective part(s), not the ent
| Published by Ramsey Electronics, Inc.
Copyright 1994 All rights reserved. Ramsey Electronics, Inc.
793 Canning Parkway Victor, NY 14564
Phone (716) 924-4560
Fax (716) 924-4555
www.ramseykits.com
Call or write for our
full line catalog!
RAMSEY TRANSMITTER KITS FM-10A FM Stereo Transmitter FM-1,2,4,5 FM Wireless Microphones PB-1 Telephone Transmitter
RAMSEY RECEIVER KITS FR-1 FM Broadcast Receiver AR-1 Aircraft Band Receiver SR-1 Shortwave Receiver AA-7 Active Antenna SC-1 Shortwave Converter
RAMSEY AMATEUR RADIO KITS FX Series VHF and UHF Transceivers HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW-700 Micro Memory CW Keyer PA Series VHF and UHF Power Amplifiers Packet Computer Interfaces QRP Power Amplifiers
RAMSEY HOBBY KITS SG-7 Personal Speed Radar SS-70 Speech Scrambler SP-1 Speakerphone MD-3 Microwave Motion Detector PH-14 Peak Hold Meter TG-1 DTMF Tone Grabber
TOTAL SOLDER POINTS
21
ESTIMATED ASSEMBLY
TIME
Beginner...............0.
|
|
