User manual ACR ELECTRONICS ACR-EM-1A REV Y

[. . . ] The operating power level is also sufficient to provide adequate sound under high ambient noise level conditions without being over-powering. Specific attention has been given to the physical size so that it can be used effectively in a crowded environment. The integrated circuit amplifier only uses a small current when turned "ON". This extends the life of the batteries so that several hours of operation may be expected when used normally in an intermittent manner. [. . . ] Clean electrical contacts with a cloth dampened with isopropyl alcohol. The power supply used in the megaphone consists of six standard 1½ volt "AA" size batteries. Current drain is minimal (12 mA) with the megaphone "ON", and increases when the user speaks into the microphone. Battery replacement is accomplished by removing three set screws () while holding the microphone and mouthpiece assembly (1) in place. The six cells, contained in three tubes with two cells per tube, are immediately accessible and will drop out when the megaphone is tilted. New batteries may be dropped into the tubes, observing polarity marking adjacent to each tube. CAUTION: Observe polarity of cells carefully before replacement. 3. 2 Battery Replacement SECTION 4 ­ TESTING, TROUBLESHOOTING & REPAIR 4. 1 Testing Note: The megaphone consists of three major assemblies; the microphone and mouthpiece assembly, the megaphone sub-assembly, and the horn and speaker assembly. If a clicking sound is heard, the speaker is operating. 5 Y1-03-0014 Rev. If the alarm is of normal amplitude and sound character, the amplifier and siren circuitry are functioning properly. If the amplification is low, check the batteries and then the amplifier. If the sound character is abnormal, check the batteries and then the siren circuitry. (ACR/EM-1A only) If no sound is heard, remove the microphone and mouthpiece assembly and the batteries. Test amplifier and speaker assembly by replacing the microphone with a spare microphone assembly. If no sound can be produced after microphone replacement, it may be assumed that the amplifier or speaker assembly is defective. Unplug the wires and apply 1 ½ volts intermittently across the speaker. If no clicks are heard, the speaker is defective. Possible faults and corrections are summarized below for ready reference. TROUBLE POSSIBLE CAUSE CORRECTION No sound from speaker Exhausted batteries, defective Replace defective component when handle is squeezed microphone, speaker or (Step 1) amplifier assembly No siren when alarm Exhausted batteries, defective Replace defective component pin is pulled (Step ) siren circuitry or defective (ACR/EM-1A only) amplifier Sound is abnormally low or Exhausted batteries or wrong Check proper insertion of distorted polarity of battery series batteries or replace batteries. Speaker does not respond to Defective speaker Step 5 Replace speaker 4. 2 Repair The megaphone consists of three major sub-assemblies; the microphone and mouthpiece assembly, the megaphone sub-assembly, and the horn and speaker assembly. Repairs are restricted to the replacement of these defective sub-assemblies or the batteries and lanyard assemblies. SECTION 5 ­ DISASSEMBLY & ASSEMBLY 5. 1 Disassembly 1. Megaphone should be disassembled for repair or replacement of components only. [. . . ] Y SECTION 7 - PARTS LIST 12 8 7 17 6 10 16 4 9 3 2 1 5 15 14 13 11 FIGURE 2 ACR/ EM-1A, ACR/EM-1D PORTABLE SAFETY MEGAPHONE ILLUSTRATED PARTS LIST Replaceable parts are illustrated in Figure (shown above) and listed in the table (shown on page 9). Part numbers shown in the "Part Number" column may be ordered from ACR unless another manufacturer's name is given in parentheses in the "Description" column. In this case, replacement parts can be obtained directly from the original manufacturer. Standard parts (MS-, AN-, etc. ) and commercially available hardware (`Commercial') should be obtained from commercial sources. Y1-03-0014 Rev. [. . . ]