source: t29-www/en/devices/functional-explanation-pianola.php @ 351

Last change on this file since 351 was 351, checked in by heribert, 7 years ago

..die Pianola durch "das" Pianola ersetzt.
Englische Seite der Pianola-Funktionserklärung probehalber hochgeladen.
Link steht bei der Pianola (miscellaneous)

File size: 7.9 KB
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1<?php
2        $seiten_id = 'functional-pianola';
3        $version = '$Id';
4        $titel = 'Functional explanation of the pianola';
5       
6        require '../../lib/technikum29.php';
7?>
8<h2>This page is in the development, please check back later</h2><br>
9<h2><?php print $title; ?></h2>
10
11
12
13<div class="desc-right auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken">
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>
15   <p>Inside view of the pianola</p>
16</div>
17   
18<p>The "pianola" is an automatic piano - the instrument shown in the picture on
19the right was built in 1915. Instruments of this type are controlled by a
20vacuum system that is powered by bellows operated either manually or by means
21of a motor. The pneumatic system of the instrument described in the following
22is powered by a motor.</p>
23
24
25<div class="desc-left auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken">
26   <a class="popup" href="fotos/abfuehlkamm.jpg"><img src="fotos/thumb.abfuehlkamm.jpg" alt="Touch sliding block" width="268" height="109"></a>
27   <p>Touch sliding block</p>
28</div>
29
30<div class="desc-left auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken" style="clear: left;">
31   <a class="popup" href="fotos/notenrolle.jpg"><img src="fotos/thumb.notenrolle.jpg" alt="music roll" width="268" height="175"></a>
32   <p>Music roll</p>
33
34</div>
35<!--<div class="left-thumb" style="width: 260px;">
36   <img src="zoomgrafiken/rolle.png" alt="Rolle schematisch">
37   <p>Die ablaufende Rolle und die Abtastung rein schematisch</p>
38</div>-->
39The piano roll is a strip of paper, many meters long, with holes punched in
40rows. Single holes or sequences of holes represent notes. This paper strip
41moves over a pickup bar with 88 openings (one for each key of the piano). In
42addition to these, this pickup contains additional openings which are used to
43control the pedals, the attack and the like.
44
45
46</p>
47<div class="desc-right auto-bildbreite borderless no-copyright" title="Zum Vergrößern klicken">
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>
49   <p>Back view of the pianola</p>
50</div>
51<p>Clearly visible in the picture of the right are the yellow colored lead tubes
52that connect the pickup bar with the pneumatic amplifiers. These amplifiers are
53called "relays" and amplify the tiny differential pressures delivered by the
54pickup mechanism sufficiently to actuate the keys and pedals of the piano.</p>
55
56
57<div class="box center" title="Zum Vergrößern klicken">
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
59(relay) element"></a>
60   <p> Schematic diagram of a single amplifier/actuator
61(relay) element
62   (<a href="zoomgrafiken/schema-uebersicht.png">größeres Bild</a>)</p>
63</div>
64
65
66<!--
67    Befehle zum Generieren der Thumbnails:
68
69    $ for bild in *.png; do convert -verbose $bild -resize 200x150\> -size 200x150 xc:white +swap -gravity center -composite thumb.$bild; done;
70-->
71
72<h3><a href="einzelbilder/Bild1.png">Picture 1</a>: Quiescent state</h3>
73<div class="box left">
74    <a class="thumb" href="einzelbilder/Bild1.png"><img src="einzelbilder/thumb.Bild1.png" alt="Amplifier/actuator in quiescent state"></a>
75</div>
76
77<p>The schematic diagram shows one relay element. 88 of these are necessary to
78control all of the piano's keys. Due to their size, these 88 relays are mounted
79in three rows. Yellow color denotes part of the vacuum system while blue marked
80areas are at atmospheric pressure. </p>
81
82<h3><a href="einzelbilder/Bild2.png">Picture 2</a>: Hole in the piano roll, air enters the pickup bar</h3>
83<div class="box left">
84    <a href="einzelbilder/Bild2.png"><img src="einzelbilder/thumb.Bild2.png" alt="Schema des pneumatischen Systems während Luft einströmt"></a>
85</div><div class="box right">
86    <a href="einzelbilder/Bild2.png"><img src="einzelbilder/big.Bild2.png" alt="Ausschnitt aus dem Schema des pneumatischen Systems, während Luft einströmt"></a>
87</div>
88
89    <p>A hole in the piano roll allows air to enter the corresponding hole in the
90pickup bar. A small "pillow" located under the right valve of the relay is
91inflated by this stream of air which in turn opens the valve.
92</p>
93
94
95<h3><a href="einzelbilder/Bild3.png">Picture 3</a>: Amplification:</h3>
96<div class="box left">
97    <a href="einzelbilder/Bild3.png"><img src="einzelbilder/thumb.Bild3.png" alt="Schema des pneumatischen Systems, erster Kolben bewegt sich"></a>
98</div><div class="box right">
99    <a href="einzelbilder/Bild3.png"><img src="einzelbilder/big.Bild3.png" alt="Vergrößerung des Verstärkungseffekts durch den Kolben"></a>
100</div>
101
102<p>This right valve allows air to enter the left part of the relay which is built
103in a similar way. Another "pillow" actuates the left valve which is much bigger
104than the left valve and thus allows more air to flow. These two valves in fact
105act like an amplifier: The small pressure difference sensed by the pickup bar
106controls the first (right) valve which acts as a first amplifier stage. This
107controls the second (left) valve which acts as a power amplifier operating the
108the bellow shown below the relay unit.</p>
109
110
111<h3><a href="einzelbilder/Bild4.png">Picture 4</a>: Contracting the bellow</h3>
112<div class="box left">
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>
114</div><div class="box right">
115    <a href="einzelbilder/Bild4.png"><img src="einzelbilder/big.Bild4.png" alt="Ausschnitt aus dem Schema in der jetzigen Position"></a>
116</div>
117
118<p>The left valve of the relay connects the bellow located under the relay block
119with the evacuated part of the pneumatic system. When activated, this valve
120will cause the bellow to contract which in turn moves the corresponding key of
121the piano.</p>
122
123
124<h3 class="clear"><a href="einzelbilder/Bild5.png">Picture 5</a>: Preview of a tone</h3>
125<div class="box left">
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>
127</div><div class="box right">
128    <a href="einzelbilder/Bild5.png"><img src="einzelbilder/big.Bild5.png" alt="Vergrößerung der Bewegung des Blasebalges"></a>
129</div>
130<p>Without additional hardware, the bellow would stay in the contracted state
131after being actuated once. Thus, some means are necessary to release the bellow
132after a note and ready the system to play the next note. If there is no hole in
133the piano roll following the hole which actuated the bellow, the bellow must be
134returned to its inflated state as quickly as possible. </p>
135
136
137<p>The picture on the right shows a small connection between the tube coming from
138the pickup strip and the vacuum system on the far right. This connection has a
139very small diameter so that it does not negatively affect the inrushing air
140current from the pickup bar when a hole is detected. If there is no hole, this
141connection withdraws the remaining air at atmospheric pressure from the right
142valve system thus closing this valve which, in turn, will close the second
143valve, which will eventually cause the bellow to inflate again. Now the
144pianola is ready to play the next note. </p>
145
146<div class="right">
147        <img src="entlueftung.png" alt="Die Entlüftungskammer">
148</div>
149
150<p>The pianola is able to play pieces which were impossible to play for a human
151player. Accordingly, there are pieces composed for the pianolo exclusively
152(like the "Studies for Player Piano" by Conlon Nancarrow).
153
154It is impressive to see what can be done by more or less simple mechanical
155systems.
156
157
158
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