Portable, Radio-Controlled Sounder Construction: Engineering Goals

  1. Prototype first horn
  2. Build seven total horns
  3. Each sounder will operate separately
  4. Each sounder will be built on a steel 2 wheel hand truck for easy mobility
    1. strapping, bungie-cords, welding http://www.harborfreight.com/bigfoot-hand-truck-97568.html#<script%20type=
      1. $45 as shown
  1. Best option: Self-powered
    1. Advantages
      1. Sounder placement can be anywhere the unit can be wheeled within 1 mile
        1. Provides the option to place sounders in Lake Eola for Oct 25
          1. Having Sounders in the lake provides me with superior musical options
          2. Swan boats with sounders could change positions within the performance
        2. Sounders can be placed on buildings, rooftops, wilderness, etc
      2. Performances would not require necessary bureaucracy to acquire power from performance location
      3. Performances would be safer for the public
        1. Sounders could be at a safe distance from population on ground
        2. Lack of 120V power cables on ground to supply electricity to each sounder
    2. Disadvantages
      1. Engineering challenge to provide 75 cubic feet per minute at 100psi
        1. Stored energy in the form of compressed air to activate horn
        2. Stored energy in the form of electricity from batteries to control solenoid and radio
  2. Acceptable option: External Power source – 120V
    1. Advantages
      1. Ample power to run on-board compressors and radio
    2. Disadvantages
      1. Sounder placement limited to 120V power placement
  3. Known Specifications and Requirements:
    1. Horns need to be controllable from 1 mile line-of-sight
    2. Horns need to produce a short staccato note (approx 250-300msec) as loudly as possible
    3. Horns require 100-125 psi to operate most efficiently, but will operate from 20-150psi
      1. Requires a Direct Acting Solenoid actuated valve to activate horn with a minumum MOPD (Operating Pressure Differential) of 25psi
    4. All train horn require 75 cu feet per minute of airflow
      1. 1.25 cu feet per second
      2. 0.63 per half note @ 120bpm
      3. 0.31 cu ft  per quarter note @ 120bpm
      4. 0.16 per 1/8th note @ 120bpm
      5. 0.08 cu ft per 1/16th note @ 120bpm

 

 

PROTOTYPE A: “High Pressure” sounder

 

  1. High Pressure Sounder 
    1. Advantages
      1. Ample air supply! Supply available for 350 seconds of constant note (5.8min)
      2. No need for 120V power or on-board air compressor
      3. Simple air circuit
    2. Disadvantages
      1. Hi pressure bottle contains a great deal of stored energy – safety first
      2. Paying for re-filling bottles will be necessary 
        1. Available hi pressure home compressor(Freedom8 4500psi compressor $1200) http://bit.ly/1mmF3dE
          1. Requires standard garage compressor as first stage (85psi)

 

PART

COST

Nathan Air Chime train horn

on loan (free)

DOT approved 4500psi Cylinder

$575 new (+ship)http://bit.ly/1e1QQXz

1-5000psi in-line gauge

$39 new (+ship) http://bit.ly/1hBFii0

4500psi Inline Regulator (need to find exact)

$125 new + http://bit.ly/1dGNEUU

Direct Solenoid with over 150psi MOPD

approx $50

Radio equipment

approx $100 parts

 

       Prototype B: Low Pressure Sounder

 

  1. Low Pressure Sounder
    1. Advantages
      1. Greater safety in lower pressure (but still dangerous)
      2. No need to pay for refills
      3. Possibly cheaper to maintain
      4. Compressor will be able to maintain if music requires no more than the available .61 cfm 
        1. .61 cfm is less than a half note @120bpm
        2. Compressors will run almost constantly to maintain pressure
    2. Disadvantages
      1. Limited air supply at pressure will force dependance on compressor to maintain constant loudness and pitch
      2. Compressors will run through entire piece, if horn is played often
      3. Batteries will be expensive in order to provide sufficient power to run both compressor, solenoid, plus radio requirements
        1. Cheaper solid piston (WOB-L) compressor, Thompson 327CD40/12 Requires 16.5A to run and 110A at start (12V)
        2. Expensive articulated piston compressor, Thompson TA4101DC 12v requires 28A to run and 198A to start (12v)
        3. Battery may be large and heavy
        4. High startup amperages might cause brown-out conditions for radio
      4. Compressor may not meet musical requirement (0.68 cu ft per half note @120bpm)
        1. Cheaper solid piston (WOB-L) compressor, Thompson 327CD40/12, is only able to supply 0.61cfm @ 100psi
        2. Expensive articulated piston compressor, Thompson TA4101DC 12v is only able to supply 0.95 cfm@100 psi 
          1. Best of class: Articulated Piston Compressor: Thompson TA5102DC can only provide 1.61 CFM@100psi – very expensive
      5. Compressor noise
      6. Unit may be too large for inexpensive hand truck mounting

 

PARTS

COST

Nathan Air Chime train horn

on loan (free)

Air receiver tank 60 gallon (20″x48″), 0-200psi gauge

$381 new (+ship)http://bit.ly/1jdSTPB

Thomas Compressor 337CDC56/24v or TA-4101DC12v

$125 (ebay) – 885 http://bit.ly/1kKMhK9

Regulator/compressor switch 

 

Direct Solenoid with over 100psi MOPD

approx $50

Radio equipment

approx $100 parts

 

 

 

  • Reply

    Krickiblatt

    02 02 2014

    Nice layout on the design decisions.

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