Model PA300 Electronic Siren
Price $4.00 Model PA300* ELECTRONIC SIREN INSTALLATION, SERVICE, AND OPERATING INSTRUCTIONS LIMITED WARRANTY The Signal Division, Federal Signal Corporation (Federal), warrants each new product to be free from defects in material and workmanship, under normal use and service, for a period of two years on parts replacement and one year on labor from the date of delivery to the first user-purchaser. During this warranty period, the obligation of Federal is limited to repairing or replacing, as Federal may elect, any part or parts of such product which after examination by Federal discloses to be defective in material and/or workmanship. Federal will provide warranty for any unit which is delivered, transported prepaid, to the Federal factory or designated authorized warranty service center for examination and such examination reveals a defect in material and/or workmanship. This warranty does not cover travel expenses, the cost of specialized equipment for gaining access to the product, or labor charges for removal and re-installation of the product. Lamps, flash tubes, or batteries are not covered under warranty. This warranty does not extend to any unit which has been subjected to abuse, misuse, improper installation or which has been inadequately maintained, nor to units which have problems relating to service or modification at any facility other than the Federal factory or authorized warranty service centers. THERE ARE NO OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL FEDERAL BE LIABLE FOR ANY LOSS OF PROFITS OR ANY INDIRECT OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY SUCH DEFECT IN MATERIAL OR WORKMANSHIP. SECTION I GENERAL DESCRIPTION reproduction without feedback “squeal”. The microphone push-to-talk switch overrides any siren signal for instant PA use. PA and radio volume are adjustable by means of a front panel GAIN control. Radio inter-connect wires are built-in. No additional cables are required. The Model PA300's 100-watt output is designed to drive a single high power speaker. The Tap II feature allows the driver to change the siren sound from wail to yelp (or vice-versa) via the vehicle's horn ring. Tap II provides especially effective traffic clearing capability. In addition to Tap II, additional alternate sounds can be activated in two other selector switch positions by depressing and holding the horn ring for as long as the alternate sound is desired. The charts in Section IV of this manual illustrate the operation of these features more fully. Figure 1-1. Model PA300* Electronic Siren. The Federal Model PA300 (figure 1-1) is a precision built, efficient and economical, full-featured electronic siren of advanced design. It provides wail, yelp and hi-lo siren tones, as well as the Tap II feature, public address (PA), radio rebroadcast and an air horn sound. Other special features of the Model PA300 include: • High degree of reliability is achieved through the use of integrated circuits and silicon output transistors. The siren may be installed in positive or negative ground vehicles with 12-volt electrical systems. It is protected against failure modes (including reversed polarity) by a fuse that is replaceable without tools. No components protrude from the bottom of the siren to interfere with mounting arrangements. • Control panel is illuminated with non-glare lighting. • Newly designed printed circuit board provides improved performance and durability under a wide range of environmental conditions. A noise-cancelling microphone is wired-in to prevent loss or theft. It provides high quality voice -1- SECTION II SPECIFICATIONS Input Voltage . . . . . . . . . . . . . 11VDC to 16VDC (16V operation limited to 15 minutes). Polarity . . . . . . . . . . . . . Negative or positive ground. Standby Current . . . . . . . . . . . . 120ma. max. (not incl. panel light). Operating Temperature Range . . . . . . . -30°C (-22°F) to +60°C (+149°F). Operating Current (14VDC-Wail mode) . . . . 10 amperes, max. Frequency Range . . . . . . . . . . . . 725 to 1575Hz. Cycle Rate . . . . . . . . . . . . Wail- 12 cycles/min. Yelp- 180 cycles/min. Hi-Lo- 60 cycles/min. Voltage Output (approx.) . . . . . . . . . 64V peak-to-peak. Dimensions (HWD) . . . . . . . . . . 2-1/2" (6.35cm) x 6-1/2" (16.51cm) x 8-1/2" (21.59cm). Net Weight (incl. microphone). . . . . . . . 4-1/2 lbs. (2.04kg). Shipping Weight . . . . . . . . 6-1/2 lbs. (2.94kg). . . . . . . . . . NOTE The following parameters were obtained with the radio input potentiometer and GAIN control set at maximum. Audio Frequency Range . . . . . . 300 to 10,000Hz. Harmonic Audio Distortion (300-3,000Hz). . . . 10% max. all power levels from 1/2 to 50 watts (frequency response ±3dB). Input Impedance (Radio) . . . 2000 ohms. Input voltage required to obtain 20VRMS across speaker load (Radio) . . . . . . . . . . 0.55VRMS. . . . . . . . . . . -2- SECTION III INSTALLATION SAFETY MESSAGE TO INSTALLERS OF ELECTRONIC SIRENS WARNING The lives of people depend on your proper installation and servicing of Federal products. It is important to read and follow all instructions shipped with the products. In addition, listed below are some other important safety instructions and precautions you should follow: • Sound output will be severely reduced if any objects are in front of the speaker. If maximum sound output is required for your application, you should ensure that the front of the speaker is clear of any obstructions. • Install the speaker(s) as far forward on the vehicle as possible, in a location which provides maximum signaling effectiveness and minimizes the sound reaching the vehicle’s occupants. Refer to the National Institute of Justice guide 500-00 for further information. • Mounting the speakers behind the grille will reduce the sound output and warning effectiveness of the siren system. Before mounting speakers behind the grille, make sure the vehicle operators are trained and understand that this type of installation is less effective for warning others. • Sound propagation and warning effectiveness will be severely reduced if the speaker is not facing forward. Carefully follow the installation instructions and always install the speaker with the projector facing forward. • DO NOT install the speaker(s ) or route the speaker wires where they may interfere with the operation of air bag sensors. • Installation of two speakers requires wiring speakers in phase. • Never attempt to install aftermarket equipment, which connects to the vehicle wiring, without reviewing a vehicle wiring diagram - available from the vehicle manufacturer. Insure that your installation will not affect vehicle operation and safety functions or circuits. Always check vehicle for proper operation after installation. • DO NOT install equipment or route wiring or cord in the deployment path of an air bag. • Locate the control head so the vehicle, controls, and microphone can be operated safely. • When drilling into a vehicle structure, be sure that both sides of the surface are clear of anything that could be damaged. Before Installation Qualifications • To properly install an electronic siren: you must have a good understanding of automotive electrical procedures and systems, along with proficiency in the installation and service of safety warning equipment. Always refer to the vehicle's service manuals when performing equipment installations on a vehicle. Sound Hazards • Your hearing and the hearing of others, in or close to your emergency vehicle, could be damaged by loud sounds. This can occur from short exposures to very loud sounds, or from longer exposures to moderately loud sounds. For hearing conservation guidance, refer to federal, state, or local recommendations. OSHA Standard 1910.95 offers guidance on “Permissible Noise Exposure.” • All effective sirens and horns produce loud sounds (120 dB) that may cause permanent hearing loss. Always minimize your exposure to siren sound and wear hearing protection. Do not sound the siren indoors or in enclosed areas where you and others will be exposed to the sound. • Federal Signal siren amplifiers and speakers are designed to work together as a system. Combining a siren and speaker from different manufacturers may reduce the warning effectiveness of the siren system and may damage the components. You should verify or test your combination to make sure the system works together properly and meets federal, state and local standards or guidelines. During Installation • • • • DO NOT get metal shavings inside the product. Metal shavings in the product can cause the system to fail. If drilling must be done near the unit, place an ESD approved cover over the unit to prevent metal shavings from entering the unit. Inspect the unit after mounting to be sure there are no shavings present in or near the unit. After Installation DO NOT connect this system to the vehicle battery until ALL other electrical connections are made, mounting of all components is complete, and you have verified that no shorts exist. If wiring is shorted to vehicle frame, high current conductors can cause hazardous sparks resulting in electrical fires or flying molten metal. Be sure the siren amplifier and speaker(s) in your installation have compatible wattage ratings. In order for the electronic siren to function properly, the ground connection must be made to the NEGATIVE battery terminal. • After installation, test the siren system and light system to ensure that it is operating properly. • Test all vehicle functions, including horn operation, vehicle safety functions and vehicle light systems, to ensure proper operation. Ensure that installation has not affected vehicle operation or changed any vehicle safety function or circuit. • After testing is complete, provide a copy of these instructions to the instructional staff and all operating personnel. • File these instructions in a safe place and refer to them when maintaining and/or reinstalling the product. Failure to follow all safety precautions and instructions may result in property damage, serious injury, or death to you or others. -3- C. Secure the mounting bracket to the dash with (2 each) 1/4-20 x 3/4 hex head screws, 1/4 split lockwashers and 1/4-20 hex nuts as shown in figure 3-1. 3-1. UNPACKING. After unpacking the Model PA300, examine it for damage that may have occurred in transit. If the equipment has been damaged, file a claim immediately with the carrier stating the extent of damage. Carefully check all envelopes shipping labels and tags before removing or destroying them. D. Secure the PA300 unit to the mounting bracket with black 1/4-20 x 7/16 hex head screws and 1/4 split lockwashers. 3-2. MOUNTING BRACKET. E. Tilt the unit to the desired position. Tighten the black 1/4-20 x 7/16 hex head screws. WARNING 3-3. POWER CABLE INSTALLATION. When installing equipment inside air bag equipped vehicles, the installer MUST ensure that the equipment is installed ONLY in areas recommended by the vehicle manufacturer. The power cable included in the carton is equipped with a twelve-prong plug (P5) that mates with the connector (J5) on the rear of the electronic siren (see figure 3-2). The various wires on the connector must be connected as follows: Failure to observe this warning will reduce the effectiveness of the air bag, damage the air bag, or potentially damage or dislodge the equipment, causing serious injury or death to you or others. WARNING Failure to observe this WARNING may result in fire, burns or blindness. If shorted to vehicle frame, high current conductors can cause hazardous sparks resulting in electrical fires or molten metal. The PA300 comes equipped with a swinging bracket which enables it to be mounted in variety of positions. Positioning the bracket above the unit allows mounting to the underside of the dash. Positioning the bracket below the unit will permit mounting on any horizontal surface. DO NOT connect this system to vehicle battery until ALL other electrical connections are made and mounting of all components is complete. The unit should be mounted in a position that is both comfortable and convenient to the operator. Keep visibility and accessibility of controls in mind. To install the unit under the dash, determine the mounting location and proceed as follows (see figure 3-1). Verify that no short circuits exist, before connecting to the Positive (+) battery terminal. CAUTION The unit must be installed in an adequately ventilated area. Never install near heater ducts. A. Use one of the mounting brackets as a template and scribe two drill positioning marks at the selected mounting location under the dash. CAUTION Before drilling holes in ANY part of a vehicle, be sure that both sides of the mounting surface are clear of parts that could be damaged; such as brake lines, electrical wiring or other vital parts. B. Drill two 1/4-inch diameter holes at the position marks. Figure 3-1. installation of PA300 Under Dash. -4- CAUTION The horn ring transfer circuit of the siren is capable of switching a maximum of 2amperes. Some vehicles do not have a horn relay and, consequently, will draw more than 2-amperes when the vehicle horn is activated. Consult your vehicle service manual or a qualified mechanic to determine the current required to activate the horn. If it is less than 2-amperes, perform the procedure in step 3. If it is greater than 2-amperes, perform steps 4 through 10. Figure 3-2. Rear View of PA300. A. Speaker. CAUTION Connecting a low power speaker (58W), or two speakers, to the unit will damage the siren or speaker(s). Always use one 11-ohm, high power (100W) speaker. 3. Splice the white control cable wire (P5, pin 10) to the horn side of the cut wire. Insulate the splice with a wire nut. The unit is designed to operate with one 11ohm, high power (100W) speaker. 4. Obtain a SPST relay of sufficient contact current capacity to activate the vehicle horn. Refer to figure 3-4 while performing the following steps. Connect the speaker leads (18 gauge wire) as shown in Control Cable Wiring Diagram, figure 3-3. 5. Mount the relay in a suitable location. 6. Connect the horn side of the wire cut in step 1 to the relay contact terminal. B. Radio. To allow incoming radio messages to be rebroadcast over the outside speakers, connect the two brown zip cord leads (P5, pins 9 and 12) across the two-way radio’s speaker. 7. Determine the “sense” of the vehicle’s horn ring activation circuit, i.e., does the horn circuit require a switched positive voltage or switched ground for activation. C. Horn Ring. 8. Connect the relay wiper terminal to the positive or negative potential determined in step 7. In order to utilize the Tap II and Press-andHold features of the siren, the following procedure must be performed. 9. Connect the white control cable wire to one end of the relay coil. 1. Locate the wire that connects the vehicle horn ring switch to the horn or horn relay. Cut this wire. 10. Connect the other end of the relay coil to the opposite potential of that connected to the wiper in step 8. 2. See figure 3-4. Splice the white/yellow control cable wire (P5, pin 7) to the horn ring side of the wire that was cut in step 1. Insulate the splice with the wire nuts (supplied). D. Connection to Power Source. The PA300 can operate from any 12-volt positive or negative ground vehicle electrical system. Figure 3-3. Control Cable Wiring Diagram. Figure 3-4. Horn Ring Connections. -5- Therefore, before making any electrical connections, determine the polarity of the vehicle electrical system ground. the battery. If necessary, additional #14 gauge or heavier wire can be spliced to the red lead. WARNING Power for the siren can be obtained from the vehicle’s power distribution center or directly from the vehicle battery. If power is going to be obtained directly from the vehicle battery, drill a hole in the vehicle firewall for the power lead to enter the engine compartment. Place a grommet or similar device in the hole to pro-tect the wire against damage from rough edges. If wires are shorted to the vehicle frame or each other, high current conductors can cause hazardous sparks resulting in electrical fires and molten metal. Verify that no short circuits exist before connecting to the Positive (+) battery terminal. DO NOT connect this system to the vehicle battery until ALL other electrical connections are made and mounting of all components is complete. CAUTION Before drilling holes in ANY part of the vehicle, ensure that both sides of the surface are clear of parts that could be damaged; such as brake lines, fuel lines, electrical wiring or other vital parts. Failure to observe this WARNING will result in fire, burns and blindness. d. Connect the in-line fuseholder lead to the positive (+) battery terminal. If your vehicle has a negative ground electrical system, perform the procedure in paragraph 1. Perform the procedure in paragraph 2, if the vehicle has a positive ground system. 1. e. Connect the black wire to the negative terminal of the battery. 2. Negative Ground. Positive Ground. a. Connect the green (P5, pin 5) control cable lead to the vehicle chassis as close as practical to the siren. Scrape paint away from the selected bolt hole to ensure a good electrical connection to the chassis. a. Connect the green (P5, pin 5) control cable lead to the vehicle chassis as close as practical to the siren. Scrape paint away from the selected bolt hole to ensure a good electrical connection to the chassis. b. Route the black (P5, pin 4) and the red (P5, pin 6) control cable leads, through the previously drilled hole, into the engine compartment. Route the wire through existing clamps and holders toward the battery. b. Route the red (P5, pin 6) and the black (P5, pin 4) control cable leads, through the previously drilled hole, into the engine compartment. Route the wires through existing clamps and holders toward the battery. c. To protect the black wire when connected to the battery terminal, use an in-line fuseholder and 20-ampere fuse (not supplied). The fuseholder should be installed as close as practical to the battery. If necessary, additional #14 gauge or heavier wire can be spliced to the black lead. c. To protect the red wire when connected to the battery terminal, use an in-line fuseholder and 20-ampere fuse (not supplied). The fuseholder should be installed as close as practical to -6- the microphone push-to-talk switch, speak in a normal voice, and adjust the GAIN control for the desired sound level outside the vehicle. Turn-on the vehicle’s two-way radio and adjust the volume to a comfortable listening level inside the vehicle. Then set the Selector switch to RADIO. Stand outside of the vehicle and note the radio rebroadcast loudness. If the sound volume is too loud or too soft, adjust R11 through the hole at the bottom of the siren (see figure 3-6) to the desired sound level. WARNING If wires are shorted to the vehicle frame or each other, high current conductors can cause hazardous sparks resulting in electrical fires and molten metal. Verify that no short circuits exist before connecting to the Positive (+) battery terminal. After the adjustment is completed, the loudness of the radio rebroadcast and public address may be varied with the front panel GAIN control. DO NOT connect this system to the vehicle battery until ALL other electrical connections are made and mounting of all components is complete. 3-6. TESTING AFTER INSTALLATION. Failure to observe this WARNING will result in fire, burns and blindness. WARNING d. Connect the in-line fuseholder lead to the negative (hot) battery terminal. All effective sirens and horns produce loud sounds (120 dB) that may cause permanent hearing loss. Always minimize your exposure to siren sound and wear hearing protection. Do not sound the siren indoors or in enclosed areas where you and others will be exposed to the sound. e. Connect the red wire to the positive terminal of the battery. 3-4. AIR HORN PRESS-AND-HOLD MODIFICATION. After installation; test the electronic siren, including horn operation, to ensure that it is operating properly. The unit comes from the factory set so that the peak-and-hold sound will be heard when the Selector switch is set to MANUAL and the vehicle horn ring is activated. To change the sound to air horn, merely move jumpers JU1 and JU2 from the “PEAK” position on the P.C. board to the “AIR” position (see figure 3-5). After testing is complete, provide a copy of this manual to all operating personnel. 3-5. RELATIVE PA LOUDNESS ADJUSTMENT. After the PA300 is completely installed in the vehicle, set the Selector switch to MANUAL. Depress Figure 3-5. Press and Hold Modification. Figure 3-6. Relative PA Loudness Adjustment. -7- SECTION IV OPERATION SAFETY MESSAGE TO OPERATORS OF FEDERAL SIGNAL ELECTRONIC SIRENS AND LIGHT/SOUND SYSTEMS WARNING • The lives of people depend on your safe operation of Federal products. It is important to read and follow all instructions shipped with the products. In addition, listed below are some other important safety instructions and precautions you should follow: Signaling Limitations • Be aware that the use of your visual and audible signaling devices does not give you the right to force your way through traffic. Your emergency lights, siren, and actions are REQUESTING the right-of-way. • Although your warning system is operating properly, it may not alert everyone. People may not hear, see, or heed your warning signal. You must recognize this fact and continue driving cautiously. • Situations may occur which obstruct your warning signal when natural or man-made objects are between your vehicle and others. This can also occur when you raise your hood or trunk lid. If these situations occur, be especially careful. Qualifications • To properly use an electronic siren and speaker(s): you must have a good understanding of general vehicle operation, a high proficiency in the use of safety warning equipment, and thorough knowledge of state and federal UNIFORM TRAFFIC CODES. Sound Hazards • • Your hearing and the hearing of others, in or close to your emergency vehicle, could be damaged by loud sounds. This can occur from short exposures to very loud sounds, or from longer exposures to moderately loud sounds. For hearing conservation guidance, refer to federal, state, or local recommendations. OSHA Standard 1910.95 offers guidance on “Permissible Noise Exposure.” Driving Limitations All effective sirens and horns produce loud sounds (120 dB) that may cause permanent hearing loss. Always minimize your exposure to siren sound, roll up your windows and wear hearing protection. Do not sound the siren indoors or in enclosed areas where you and others will be exposed to the sound. Only use the siren for emergency response situations. Sound Limitations • • Frequently inspect the speaker to ensure that it is clear of any obstruction, such as mud or snow, which will reduce maximum sound output. Before using the vehicle, check to see if the siren speakers are concealed from view. If the siren speaker is not in clear view on the front of the vehicle, use extra caution when operating the vehicle. A concealed siren speaker installation is less effective at warning others. • At the start of your shift, you should ensure that the light/sound system is securely attached to the vehicle and operating properly. • If the unique combination of emergency vehicle equipment installed in your vehicle has resulted in the siren controls being installed in a position that does not allow you to operate them by touch only, OPERATE CONTROLS ONLY WHILE YOUR VEHICLE IS STOPPED. • If driving conditions require your full attention, you should avoid operating the siren controls while the vehicle is in motion. Continuing Education • Maximum sound output will be severely reduced if any objects are in front of the speaker. If your installation has obstructions in front of the speaker, drive even more cautiously. File these instructions in a safe place and refer to them periodically. Give a copy of these instructions to new recruits and trainees. Failure to follow these safety precautions may result in property damage, serious injury, or death to you, to passengers, or to others. -8- 4-1. GENERAL. C. WAIL. All controls utilized during normal operation of the Model PA300 are located on the front panel (see figure 4-1). In this position, the siren produces a continuous “wailing” sound, up and down in frequency. D. YELP. The wired-in noise cancelling microphone provides high quality voice reproduction in the public address mode. The microphone push-to-talk switch will override all siren functions, except radio rebroadcast, for instant PA use. In this position; a continuous, rapid “warbled” tone is generated. E. HI-LO. 4-2. GAIN CONTROL. In this position, a two-tone sound will be heard. This distinctive tone may be reserved for any special indication or situation. The GAIN control is used to turn the siren on and off. Also, it is used to control the volume when the siren is used for public address or radio amplification. Clockwise rotation of the knob increases voice volume in the public address or radio amplification mode. The GAIN control does not control the volume of the siren signals. 4-4. HORN/SIREN SWITCH. The HORN/SIREN switch, located on the left side of the front panel, activates the electronic air horn sound (up) or peak-and-hold sound (down) in any siren mode except radio. The maximum clockwise setting of the control will be determined, in most cases by the point at which feedback or “squeal” occurs. This will depend upon the microphone gain, open windows, speaker placement, proximity of reflecting surfaces (building or other vehicles), etc. Adjust the GAIN control to a position just below the point at which feedback occurs or as desired. 4-5. TAP II FUNCTIONS. Tap II allows the driver to change the siren sound via the vehicle’s horn ring. This feature is especially effective for clearing traffic. The chart below demonstrates how the horn ring can be used to change the siren sound: 4-3. SELECTOR SWITCH. TAP II FUNCTIONS The Selector switch is a five-position rotary switch used to select the mode of operation. The following are positions on the Selector switch. Selector Switch Position A. RADIO. In this position, incoming radio messages are amplified by the siren and rebroadcast over the outside speaker. Wail Yelp First Horn Ring Tap Produces Yelp Wail Second Horn Ring Tap Produces Wail Yelp 4-6. PRESS AND HOLD FUNCTIONS. B. MANUAL. Additional alternate sounds can be activated in two other Selector switch positions, by depressing and holding the horn ring for as long as the alternate sound is desired. The chart below shows these additional “Press and Hold” functions: In this position, it is possible to operate the siren by activating the HORN/SIREN switch. The siren can also be activated by means of an auxiliary switch, such as the horn ring button (refer to paragraph 4-6). PRESS AND HOLD FUNCTIONS Selector Switch Position Hi-Lo Manual Figure 4-1. Front View. -9- Press on Horn Ring Produces Release of Horn Ring Produces Air Horn Peak and Hold or Air Horn Hi-Lo Coast down and silence or silence SECTION V CIRCUIT DESCRIPTION the control pin (IC10-6) goes low putting the switch in a high impedance state (OFF), and allows the RC rate capacitor (C11) to charge as the siren tone peaks. 5-1. GENERAL. The Model PA300 circuitry can be divided into seven functional blocks. Refer to figure 5-1 and 6-4 while reading the following paragraphs. IC12B, another astable oscillator, generates the control voltage required to generate the air-horn sound. Normally, IC12B is held in the reset state (IC12-10 low) until the air horn control line is pulled high. 5-2. RATE OSCILLATORS AND VOLTAGE CONTROLLED OSCILLATOR. The heart of the Model PA300 circuitry is the rate oscillator and VCO sections. The rate oscillator not only determines the cycling rate of each siren tone, but also generates the control voltage that operates the voltage controlled oscillator (VCO). The VCO generates a square-wave output whose frequency is directly proportional to the control voltage. The output of the VCO is coupled to the siren’s power output amplifier. IC8C, a one-of-two analog switch, selects the siren or air horn control voltage from IC12A or IC12B. IC8B selects either the RC control voltage (manual, wail and yelp modes) or the square wave control voltage (hi-lo) derived from the output of IC12A. The voltage divider network of R27, R28, R29 and CR8 provides the DC level shifting of the IC12A output necessary to obtain the desired hi-lo tone frequencies. The siren rate oscillator consists of an LM556 dual timer configured as two astable oscillators. The first astable oscillator (IC12A) employs analog switches (IC10A , IC10B) to select the resistance for the RC timing network which determines the astable oscillator’s cycling rate. IC10C , another analog switch, connects the discharge pin of IC12A to the RC timing network. When the peak function is called for, IC13, a phase-locked loop, contains the voltage controlled oscillator. C21, R46, R47, R57, and the control voltage on pin 9 determine the output frequency. Figure 5-1. Functional Block Diagram. -10- As the siren coasts down in the manual mode, the output of the VCO must be disabled to prevent frequencies lower than 350Hz from damaging the amplifier’s output transistors. IC4D, a voltage comparator, compares the VCO control voltage to the low frequency reference voltage set by R40 and R41. When the VCO control voltage drops below the reference, IC4-8 goes high and forces the inhibit pin of the VCO high through OR gate IC9D. The VCO is also inhibited when the radio or microphone push-totalk input is selected. These logic inputs are gated through IC7B, IC9C and IC9D to the VCO inhibit pin. siren function, as long as the horn ring switch is depressed. If manual or hi-lo is the selected mode and JU1 and JU2 are set to “AIR”, the window comparator output will be passed through AND gate IC5D to activate the air horn override circuitry (refer to paragraph 5-2). 5-5. AUDIO SELECTOR AND POWER AMPLIFIER. The siren has two audio inputs: radio rebroadcast and microphone public address. The radio input is derived from direct connection to the radio speaker. A fraction of the audio voltage developed across the radio balance potentiometer (R11) is applied to the input of a differential amplifier (IC4C). The differential amplifier eliminates any ground reference problem that may exist between the PA300 and various makes of radios. The microphone has a built-in transistor amplifier and therefore requires no external pre-amplifier. Resistor R14 serves as the collector bias resistor for the microphone’s amplifier. The microphone output, derived from J2-1, and the radio audio from IC4C are selected via 1 of 2 analog switch IC8A. Normally, the microphone audio is gated through the multiplexer unless the Selector switch is set to the RADlO position. The selected audio is applied to IC11-2. 5-3. SIREN MODE CONTROL. The siren mode is controlled by the logic levels applied to J2-3, 5, 6, 7, 8 and J3-1, 2 and 7 (via Selector switch SW2), HORN/SIREN switch SW3, and the microphone push-to-talk switch. IC2 buffers the control inputs. IC3 and IC9 provide most of the decoding necessary to control the rate oscillator and analog switching of the audio and VCO control voltages. 5-4. TAP II CONTROL. As long as power is applied to the siren circuitry, the vehicle’s horn ring switch will be connected through P3-5 and K1A to the inputs of a window comparator consisting of IC4A and IC4B. A positive or negative horn ring contact will result in a logic “1” pulse of equal duration at the junction of CR1 and CR2. IC11 is an audio power amplifier integrated circuit which provides the necessary power gain to drive the push-pull amplifier stages beyond driver transformer T1. A biasing network consisting of TH1, CR15, Q4, R52, R53 and R54 is activated whenever the radio or the microphone push-to-talk switch is activated. This eliminates all “crossover” distortion associated with the push-pull output amplifier. When the siren is in the wail or yelp mode, the horn ring pulse passes to the input of IC6A, is “debounced”, and then applied to toggle flip-flop IC6B. Every time the horn ring is operated, the output of IC6B (pin 5) changes state and inverts the state of the yelp control line. (The exclusive OR gate contained in IC13 functions as a controlled inverter where a logic “1” present on pin 3 forces the output (pin 2) to Y or “yelp not”.) 5-6. 8-VOLT REGULATOR, POWER CONTROL AND HORN RING TRANSFER. When the GAIN control (on/off switch) is rotated clockwise, B+ is applied to the circuit board via J3-4 and J4-4. The networks consisting of CR4, C6 and CR10, R36, C17 provide filtering of the B+ voltage for the 8-volt regulator (IC1) and the audio amplifier (IC11). The large capacitances employed insure that all control logic remains stable and prevents “popping” noises heard through the loudspeaker when power is turned off. If the Selector switch mode is changed during a Tap II operation, the circuitry consisting of IC7A, IC5B and IC7C resets the toggle flip-flop (IC6B) and allows the true state of the yelp control line to pass to the rate oscillator section. This is necessary to insure that the Selector switch position corresponds to the audible siren tone produced. Q1, Q2, Q3 and associated components form the power-on control circuitry. This network delays the activation of K1 approximately one-second after B+ is applied. During the interim, all siren control logic stabilizes allowing C15 to charge, bypassing the primary of driver transformer T1. This circuitry suppresses loud turn-on “thumps” from the loudspeaker and allows the vehicle horn ring switch to operate the siren’s Tap II feature. NOTE The reset circuitry relies on the fact that the Selector switch is of the non-shorting type. When the siren is in the manual mode, and JU1 and JU2 are left connected to “PEAK” (factory setting), the window comparator output will be passed through AND gate IC5C to activate the peak -11- SECTION VI SERVICE AND MAINTENANCE • SAFETY MESSAGE TO PERSONNEL SERVICING FEDERAL SIGNAL ELECTRONIC SIRENS WARNING The lives of people depend on your proper servicing of Federal products. It is important to read and follow all instructions shipped with the products. In addition, listed below are some other safety instructions and precautions you should follow: • Read and understand all instructions in this manual before servicing the electronic siren or speaker. • To properly service an electronic siren or speaker: you must have a good understanding of automotive electrical procedures and systems, along with proficiency in the installation and service of safety warning equipment. Always refer to the vehicle's service manuals when performing service on a vehicle. • Electronic circuit and speaker repairs must be performed by a qualified and competent electronic technician. • Your hearing and the hearing of others, in or close to your emergency vehicle, could be damaged by loud sounds. This can occur from short exposures to very loud sounds, or from longer exposures to moderately loud sounds. For hearing conservation guidance, refer to federal, state, or local recommendations. OSHA Standard 1910.95 offers guidance on “Permissible Noise Exposure.” • DO NOT connect this system to the positive terminal of the battery until servicing is complete, and you have verified that there are no short circuits to ground. • In order for the electronic siren to function properly, the ground connection must be made to the NEGATIVE battery terminal. • Failure to follow all safety precautions and instructions may result in property damage, serious injury, or death to you or others. 6-1. GENERAL. Most of the component electronic parts used in the Model PA300 are standard items that can be obtained from any TV or electronics supply shop. In order to reduce equipment down-time. Federal recommends that the entire printed circuit board (Part No. 200C860) be replaced. The printed circuit boards are relatively inexpensive allowing you to keep an adequate supply in your repair shop. The diagrams in this section should be an aid to a repairman in isolating a malfunction and locating components. The factory can and will service your equipment or assist you with technical problems, should any arise, that cannot be handled satisfactorily and promptly locally. Communications and shipments should be addressed to: All effective sirens and horns produce loud sounds (120 dB) that may cause permanent hearing loss. Always minimize your exposure to siren sound and wear hearing protection. Do not sound the siren indoors or in enclosed areas where you and others will be exposed to the sound. • Federal Signal siren amplifiers and speakers are designed to work together as a system. Combining a siren and speaker from different manufacturers may reduce the warning effectiveness of the siren system and may damage the components. You should verify or test your combination to make sure the system works together properly and meets both federal, state and local standards or guidelines. Service Department Federal Signal Corporation 2645 Federal Signal Drive University Park, IL 60466 1-800-433-9132 If any unit is returned for adjustment or repair, it can be accepted only if we are notified by letter or phone in advance of its arrival. Such notice should clearly indicate the service requested and give all pertinent information regarding the nature of malfunction and, if possible, its cause. 6-2. SIREN. A. General. After repair, test the electronic siren and speaker system to ensure that it is operating properly. Any competent TV repairman or electronic technician should have little difficulty in tracing and -12- correcting a malfunction, should any occur. For emergency replacement of any of the small components, care must be used when soldering. Heat easily impairs transistors, capacitors and circuit boards. It is therefore advisable to use longnose pliers or a similar heat sink on the lead being soldered. have a detrimental effect on the output transistors, and is therefore not recommended. Federal recommends that both output transistors be replaced should only one device prove to be defective. This practice will ensure long periods of service between failures. If IC13 or C21 are replaced, it may be necessary to adjust R57. With the Selector Switch set to MANUAL, hold the paddle switch in the SIREN position and adjust R57 for 1510 Hz ±10 Hz at the siren output. When installing new output transistors, ensure that the Sil-Pad insulators are installed between the heat-sink and transistors. CAUTION B. Removal for Servicing. Make certain that the speaker is not defective prior to installing the repaired PA300. When removing the chassis for servicing, loosen the two hexagon head screws on the underside of the unit, near the front edge. Slide the entire chassis out of the case as shown in figure 6-1. 6-3. TESTING AFTER SERVICE. WARNING All effective sirens and horns produce loud sounds (120 dB) that may cause permanent hearing loss. Always minimize your exposure to siren sound and wear hearing protection. Do not sound the siren indoors or in enclosed areas where you and others will be exposed to the sound. C. Removal of Circuit Board. The PC board is secured to the chassis by four Phillips head screws. Unplug the four wafer connectors and microphone before removing the screws. D. Replacement of Output Transistors. After installation; test the electronic siren, including horn operation, to ensure that it is operating properly. Failure of one or both of the output transistors (Q7, Q8) is usually the result of a defective speaker (short circuited voice coil). Rebroadcast of unsquelched radio or music for long periods will also After testing is complete, provide a copy of this manual to all operating personnel. -13- Figure 6-1. Chassis Removal. Figure 6-2. Internal View. -14- -15Figure 6-3. Component Location Diagram. -16Figure 6-4. Schematic Diagram. PARTS LIST Schematic Symbol Description Schematic Symbol Part No. *RESISTORS R1, 4, 14, 15 R2, 5, 6, 42, 45 R3 R7, 17, 18, 19, 22, 33, 44 R8 R9, 12 R10, 13, 20 R11 R16, 30 R21, 55 R23, 31, 32, 34, 38 R24 R25 R26 R27, 41 R28 R29 R35 R36, 49, 50 R37 R39 R40 R43, 47 R46 R48, 51 R52 R53 R54 R56 R57 R58 4700 Ohm 100K Ohm 27K Ohm 10K Ohm 100A298 100A262 100A244 100A257 68K Ohm 36K Ohm 15K Ohm 2K Ohm, Potentiometer 18K Ohm 5600 Ohm 1000 Ohm 100A261 100A275 100A239 106A203A-01 100A258 100A253 100A233 4.7K Ohm, 2% 100A713 22K Ohm, 2% 82K Ohm, 2% 33K Ohm 47K Ohm 68K Ohm, 2% 27 Ohm 10 Ohm 10K Ohm, Potentiometer, GAIN 10K Ohm 56K Ohm 1.5 Megohm 68K Ohm 150 Ohm 27 Ohm 8.2 Ohm 270 Ohm, 2 watt, Wirewound 2700 Ohm 200K Ohm, Potentiometer 470 Ohm 100A797 100A789 100A211 100A228 100A775 100A290 100A251 106A116 100A257 100A229 100A217 100A261 100A238 100A290 100A234 103A128 100A256 106A203A-03 100A248 IC1 IC2 IC3, IC9 IC4 IC5 IC6 IC7 IC8 IC10 IC11 IC12 IC13 Q1 Q2, 3, 4 Q5, 6 Q7, 8 J1, 2, 3, 4 J5 H1, 2, 3, 4 P5 K1 Z1 RT1 T1 T2 F1 DS1 SW2 SW3 TB1 107A263 108A143 108A142 108A149 107A634 108A144 107A1103 107A677A-02 107A211 108A147 107A1101 107A766 107A211 108A122 TI55 115B101 ED3002S 115B301 1N4738, 8.2V, Zener Rectifier, 6 amp. 50V 115A232 115A317 128A097 128A092A-01 128B082 128A098 128A077 128A044 128A100 128A099 128A047 128A046 128A038-01 128B079 TIS93, PNP TIS92, NPN 2N6109, PNP 2N5885, NPN, Power 125B133 125B132 125B431 125B432 MISCELLANEOUS DIODES CR1, 2, 3, 6, 7, 8, 9, 11 CR4, 5, 10, 13, 14, 15 CR16 CR17 UA78MO8CKC CD4050BE MC14071BCP LM324N MC14081BCP MC14027BCP MC14069UBCP MC14053BCP MC14066BCP LM380N NAT LM556 MC14046BCP TRANSISTORS CAPACITORS 0.001UF, 500V, Disc 10UF, 16V, Electrolytic 2.2UF, 25V, Electrolytic 1000UF, 35V, Electrolytic 10UF, 10V, Tantalum 22UF, 16V, Electrolytic 0.1UF, 35V, Tantalum 22UF, 15V, Tantalum 0.005UF, 100V, Disc 150UF, 16V, Electrolytic 0.22UF, Radial Tantalum 0.15UF, 5%, 100V, Poly 0.005UF, 100V, Disc 500UF, 15V, Electrolytic Part No. INTEGRATED CIRCUITS *Unless otherwise specified, all RESISTORS are carbon type, ±5%, 1/4 watt. C1, 2, 18, 22, 23 C3, 20 C4, 5, 13 C6, 17 C7, 8, 12, 16 C9 C10 C11 C14 C15 C19 C21 C24, 25 C26 Description -17- Connector, Wafer Connector, 12-pin Terminal, Male Plug, 12-pin Relay, 180 Ohm, 12V, DPDT Resistor Network, 9 x 10K Thermistor, 200 Ohm Transformer, Driver Transformer, Output Fuse, 15A, 3AG, 32V Lamp, 14V, Green Switch, Rotary Switch, Paddle Terminal, Strip Microphone Socket, Transistor (Q7, Q8) Socket, Lamp (DS1) Holder, Fuse (F1) Knob, GAIN control Knob, Selector Insulator (Q7, Q8) Circuit Board (without parts) Circuit Board (with parts installed) Standoff Bracket, Lamp Bracket, Mounting Bracket, Transistor (Q7, Q8) Accessory Kit Housing Wire Harness 140A170 139A152 233A106 140A154 131A130A-01 100A801 104A111 120B145 120C151A-01 148A107 149A121A 122B215 122A214 229A127 258B577-01 138A125 138A126B 143A106 141A102 141A111 235A123A-01 130C301B 200C860 230A123 8536A025 8536B022 8537B303 8537A301A 8537C002 175B434 255A198M REV. M 901 Printed in U.S.A.
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