1 | <?php |
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2 | $seiten_id = 'functional-pianola'; |
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3 | $version = '$Id'; |
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4 | $titel = 'Functional explanation of the pianola'; |
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5 | |
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6 | require '../../lib/technikum29.php'; |
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7 | ?> |
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8 | <h2>This page is in the development, please check back later</h2><br> |
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9 | <h2><?php print $title; ?></h2> |
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10 | |
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11 | |
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12 | |
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13 | <div class="desc-right auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken"> |
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14 | <a class="popup" href="fotos/pianola-offen.jpg"><img src="fotos/thumb.pianola-offen.jpg" alt="Inside view of the pianola" width="300" height="225"></a> |
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15 | <p>Inside view of the pianola</p> |
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16 | </div> |
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17 | |
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18 | <p>The "pianola" is an automatic piano - the instrument shown in the picture on |
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19 | the right was built in 1915. Instruments of this type are controlled by a |
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20 | vacuum system that is powered by bellows operated either manually or by means |
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21 | of a motor. The pneumatic system of the instrument described in the following |
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22 | is powered by a motor.</p> |
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23 | |
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24 | |
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25 | <div class="desc-left auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken"> |
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26 | <a class="popup" href="fotos/abfuehlkamm.jpg"><img src="fotos/thumb.abfuehlkamm.jpg" alt="Touch sliding block" width="268" height="109"></a> |
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27 | <p>Touch sliding block</p> |
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28 | </div> |
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29 | |
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30 | <div class="desc-left auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken" style="clear: left;"> |
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31 | <a class="popup" href="fotos/notenrolle.jpg"><img src="fotos/thumb.notenrolle.jpg" alt="music roll" width="268" height="175"></a> |
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32 | <p>Music roll</p> |
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33 | |
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34 | </div> |
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35 | <!--<div class="left-thumb" style="width: 260px;"> |
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36 | <img src="zoomgrafiken/rolle.png" alt="Rolle schematisch"> |
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37 | <p>Die ablaufende Rolle und die Abtastung rein schematisch</p> |
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38 | </div>--> |
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39 | The piano roll is a strip of paper, many meters long, with holes punched in |
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40 | rows. Single holes or sequences of holes represent notes. This paper strip |
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41 | moves over a pickup bar with 88 openings (one for each key of the piano). In |
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42 | addition to these, this pickup contains additional openings which are used to |
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43 | control the pedals, the attack and the like. |
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44 | |
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45 | |
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46 | </p> |
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47 | <div class="desc-right auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken"> |
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48 | <a class="popup" href="fotos/pianola-innen.jpg"><img src="fotos/thumb.pianola-innen.jpg" alt="Back view of the pianola" width="300" height="225"></a> |
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49 | <p>Back view of the pianola</p> |
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50 | </div> |
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51 | <p>Clearly visible in the picture of the right are the yellow colored lead tubes |
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52 | that connect the pickup bar with the pneumatic amplifiers. These amplifiers are |
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53 | called "relays" and amplify the tiny differential pressures delivered by the |
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54 | pickup mechanism sufficiently to actuate the keys and pedals of the piano.</p> |
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55 | |
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56 | |
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57 | <div class="box center" title="Zum Vergrößern klicken"> |
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58 | <a href="zoomgrafiken/schema-uebersicht.png"><img style="border: none;" src="zoomgrafiken/thumb.schema-uebersicht.png" alt="Schematic diagram of a single amplifier/actuator |
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59 | (relay) element"></a> |
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60 | <p> Schematic diagram of a single amplifier/actuator |
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61 | (relay) element |
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62 | (<a href="zoomgrafiken/schema-uebersicht.png">größeres Bild</a>)</p> |
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63 | </div> |
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64 | |
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65 | |
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66 | <!-- |
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67 | Befehle zum Generieren der Thumbnails: |
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68 | |
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69 | $ for bild in *.png; do convert -verbose $bild -resize 200x150\> -size 200x150 xc:white +swap -gravity center -composite thumb.$bild; done; |
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70 | --> |
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71 | |
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72 | <h3><a href="einzelbilder/Bild1.png">Picture 1</a>: Quiescent state</h3> |
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73 | <div class="box left"> |
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74 | <a class="thumb" href="einzelbilder/Bild1.png"><img src="einzelbilder/thumb.Bild1.png" alt="Amplifier/actuator in quiescent state"></a> |
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75 | </div> |
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76 | |
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77 | <p>The schematic diagram shows one relay element. 88 of these are necessary to |
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78 | control all of the piano's keys. Due to their size, these 88 relays are mounted |
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79 | in three rows. Yellow color denotes part of the vacuum system while blue marked |
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80 | areas are at atmospheric pressure. </p> |
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81 | |
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82 | <h3><a href="einzelbilder/Bild2.png">Picture 2</a>: Hole in the piano roll, air enters the pickup bar</h3> |
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83 | <div class="box left"> |
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84 | <a href="einzelbilder/Bild2.png"><img src="einzelbilder/thumb.Bild2.png" alt="Schema des pneumatischen Systems während Luft einströmt"></a> |
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85 | </div><div class="box right"> |
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86 | <a href="einzelbilder/Bild2.png"><img src="einzelbilder/big.Bild2.png" alt="Ausschnitt aus dem Schema des pneumatischen Systems, während Luft einströmt"></a> |
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87 | </div> |
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88 | |
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89 | <p>A hole in the piano roll allows air to enter the corresponding hole in the |
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90 | pickup bar. A small "pillow" located under the right valve of the relay is |
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91 | inflated by this stream of air which in turn opens the valve. |
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92 | </p> |
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93 | |
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94 | |
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95 | <h3><a href="einzelbilder/Bild3.png">Picture 3</a>: Amplification:</h3> |
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96 | <div class="box left"> |
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97 | <a href="einzelbilder/Bild3.png"><img src="einzelbilder/thumb.Bild3.png" alt="Schema des pneumatischen Systems, erster Kolben bewegt sich"></a> |
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98 | </div><div class="box right"> |
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99 | <a href="einzelbilder/Bild3.png"><img src="einzelbilder/big.Bild3.png" alt="Vergrößerung des Verstärkungseffekts durch den Kolben"></a> |
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100 | </div> |
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101 | |
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102 | <p>This right valve allows air to enter the left part of the relay which is built |
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103 | in a similar way. Another "pillow" actuates the left valve which is much bigger |
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104 | than the left valve and thus allows more air to flow. These two valves in fact |
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105 | act like an amplifier: The small pressure difference sensed by the pickup bar |
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106 | controls the first (right) valve which acts as a first amplifier stage. This |
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107 | controls the second (left) valve which acts as a power amplifier operating the |
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108 | the bellow shown below the relay unit.</p> |
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109 | |
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110 | |
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111 | <h3><a href="einzelbilder/Bild4.png">Picture 4</a>: Contracting the bellow</h3> |
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112 | <div class="box left"> |
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113 | <a href="einzelbilder/Bild4.png"><img src="einzelbilder/thumb.Bild4.png" alt="Schema des pneumatischen Systems: Der zweite Kolben sorgt für eine weitere Verstärkung des Effektes"></a> |
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114 | </div><div class="box right"> |
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115 | <a href="einzelbilder/Bild4.png"><img src="einzelbilder/big.Bild4.png" alt="Ausschnitt aus dem Schema in der jetzigen Position"></a> |
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116 | </div> |
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117 | |
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118 | <p>The left valve of the relay connects the bellow located under the relay block |
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119 | with the evacuated part of the pneumatic system. When activated, this valve |
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120 | will cause the bellow to contract which in turn moves the corresponding key of |
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121 | the piano.</p> |
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122 | |
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123 | |
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124 | <h3 class="clear"><a href="einzelbilder/Bild5.png">Picture 5</a>: Preview of a tone</h3> |
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125 | <div class="box left"> |
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126 | <a href="einzelbilder/Bild5.png"><img src="einzelbilder/thumb.Bild5.png" alt="Schema des pneumatischen Systems: die Luft strömt aus dem Blasebalg, er zieht sich zusammen"></a> |
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127 | </div><div class="box right"> |
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128 | <a href="einzelbilder/Bild5.png"><img src="einzelbilder/big.Bild5.png" alt="Vergrößerung der Bewegung des Blasebalges"></a> |
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129 | </div> |
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130 | <p>Without additional hardware, the bellow would stay in the contracted state |
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131 | after being actuated once. Thus, some means are necessary to release the bellow |
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132 | after a note and ready the system to play the next note. If there is no hole in |
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133 | the piano roll following the hole which actuated the bellow, the bellow must be |
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134 | returned to its inflated state as quickly as possible. </p> |
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135 | |
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136 | |
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137 | <p>The picture on the right shows a small connection between the tube coming from |
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138 | the pickup strip and the vacuum system on the far right. This connection has a |
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139 | very small diameter so that it does not negatively affect the inrushing air |
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140 | current from the pickup bar when a hole is detected. If there is no hole, this |
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141 | connection withdraws the remaining air at atmospheric pressure from the right |
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142 | valve system thus closing this valve which, in turn, will close the second |
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143 | valve, which will eventually cause the bellow to inflate again. Now the |
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144 | pianola is ready to play the next note. </p> |
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145 | |
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146 | <div class="right"> |
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147 | <img src="entlueftung.png" alt="Die Entlüftungskammer"> |
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148 | </div> |
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149 | |
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150 | <p>The pianola is able to play pieces which were impossible to play for a human |
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151 | player. Accordingly, there are pieces composed for the pianolo exclusively |
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152 | (like the "Studies for Player Piano" by Conlon Nancarrow). |
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153 | |
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154 | It is impressive to see what can be done by more or less simple mechanical |
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155 | systems. |
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156 | |
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157 | |
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158 | |
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