https://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&feed=atom&action=historyTech:Optical bell - Revision history2024-03-29T10:36:01ZRevision history for this page on the wikiMediaWiki 1.34.1https://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=906&oldid=prevMirwi: Typo fix in explanation.2018-04-03T03:11:56Z<p>Typo fix in explanation.</p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Optoring_schem.png|center|schematic]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Optoring_schem.png|center|schematic]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The circuit is shown in the schematic above. The diode D2 rectifies the positive portion of the input ringing voltage and charges up the capacitor C3. Of course the negative portion could have been used equivalently, with the diode in correct polarity connected to the negative side of C3. The maximum peak voltage observed at C3, with heavy cranking at a field phone, was about 150V. As a second stage, the capacitor C1 is now "slowly" charged form C3 trough the resistor R1. Voltage at <del class="diffchange diffchange-inline">C3 </del>will rise until the base voltage of Q1, generated from <del class="diffchange diffchange-inline">C3 </del>voltage through the divider formed by R2 and (R3+R8), is high enough to make Q1 conduct and turn on M1. The moment M1 turns on, there is a significant amount of current that starts flowing through the LED D1 and R8. The now present voltage drop over R8 will additionally feed the base of Q1 and ensures that it stays conducting until the LED current has subsided. C1 will quickly discharge into the LED, making it flash very briefly, for about 2ms, but with high brightness. When C1 voltage has fallen and the LED current has also decreased, Q1 is no longer conducting and M1 also will <del class="diffchange diffchange-inline">returne </del>to non conducting mode. As long as there is still charge in C3, C1 is again charged up via R1 and the next led flash is initiated. The time required for C1 charge up will increase with falling C3 voltage. This results in a continuously slowing down flashing of the LED.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The circuit is shown in the schematic above. The diode D2 rectifies the positive portion of the input ringing voltage and charges up the capacitor C3. Of course the negative portion could have been used equivalently, with the diode in correct polarity connected to the negative side of C3. The maximum peak voltage observed at C3, with heavy cranking at a field phone, was about 150V. As a second stage, the capacitor C1 is now "slowly" charged form C3 trough the resistor R1. Voltage at <ins class="diffchange diffchange-inline">C1 </ins>will rise until the base voltage of Q1, generated from <ins class="diffchange diffchange-inline">C1 </ins>voltage through the divider formed by R2 and (R3+R8), is high enough to make Q1 conduct and turn on M1. The moment M1 turns on, there is a significant amount of current that starts flowing through the LED D1 and R8. The now present voltage drop over R8 will additionally feed the base of Q1 and ensures that it stays conducting until the LED current has subsided. C1 will quickly discharge into the LED, making it flash very briefly, for about 2ms, but with high brightness. When C1 voltage has fallen and the LED current has also decreased, Q1 is no longer conducting and M1 also will <ins class="diffchange diffchange-inline">return </ins>to non conducting mode. As long as there is still <ins class="diffchange diffchange-inline">enough </ins>charge in C3, C1 is again charged up via R1 and the next led flash is initiated. The time required for C1 charge up will increase with falling C3 voltage. This results in a continuously slowing down flashing of the LED.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_full.png|600px|center|simulation]] <br /></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_full.png|600px|center|simulation]] <br /></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_blitz.png|600px|center|simulation - single LED flash]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_blitz.png|600px|center|simulation - single LED flash]]</div></td></tr>
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</table>Mirwihttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=801&oldid=prevMirwi: Image of hw added.2017-01-15T15:37:46Z<p>Image of hw added.</p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The measurement results of the actual built units match pretty well with the simulation. The voltage across R8 is perfectly suited for monitoring the LED current with an oscilloscope...</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The measurement results of the actual built units match pretty well with the simulation. The voltage across R8 is perfectly suited for monitoring the LED current with an oscilloscope...</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:hw_optical_bell.jpg|center|Hardware build of the optic bell circuit.]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:hw_optical_bell.jpg<ins class="diffchange diffchange-inline">|600px</ins>|center|Hardware build of the optic bell circuit.]]</div></td></tr>
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</table>Mirwihttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=790&oldid=prevMirwi at 15:33, 15 January 20172017-01-15T15:33:51Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The measurement results of the actual built units match pretty well with the simulation. The voltage across R8 is perfectly suited for monitoring the LED current with an oscilloscope...</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The measurement results of the actual built units match pretty well with the simulation. The voltage across R8 is perfectly suited for monitoring the LED current with an oscilloscope...</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[[File:hw_optical_bell.jpg|center|Hardware build of the optic bell circuit.]]</ins></div></td></tr>
</table>Mirwihttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=185&oldid=prevPhilmacFLy at 12:27, 6 January 20172017-01-06T12:27:40Z<p></p>
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<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">== Opitcal bell ==</del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>At the [[Events:GPN16|GPN16]] the plan was to put field phones in all lecture halls, close to the speaker desks. To be allowed to do so, the requirement was that these phones should not disturb any lectures by loud ringing. So the phones were silenced (TODO: link to description) and equipped with the optical ring indicator described below, before deployment.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>At the [[Events:GPN16|GPN16]] the plan was to put field phones in all lecture halls, close to the speaker desks. To be allowed to do so, the requirement was that these phones should not disturb any lectures by loud ringing. So the phones were silenced (TODO: link to description) and equipped with the optical ring indicator described below, before deployment.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
</table>PhilmacFLyhttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=182&oldid=prevPhilmacFLy: PhilmacFLy moved page Tech:Opitcal bell to Tech:Optical bell2017-01-06T12:26:32Z<p>PhilmacFLy moved page <a href="/index.php/Tech:Opitcal_bell" class="mw-redirect" title="Tech:Opitcal bell">Tech:Opitcal bell</a> to <a href="/index.php/Tech:Optical_bell" title="Tech:Optical bell">Tech:Optical bell</a></p>
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</table>PhilmacFLyhttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=178&oldid=prevPhilmacFLy: PhilmacFLy moved page Tech chaos optoring to Tech:Opitcal bell2017-01-06T12:24:27Z<p>PhilmacFLy moved page <a href="/index.php/Tech_chaos_optoring" class="mw-redirect" title="Tech chaos optoring">Tech chaos optoring</a> to <a href="/index.php/Tech:Opitcal_bell" class="mw-redirect" title="Tech:Opitcal bell">Tech:Opitcal bell</a></p>
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</table>PhilmacFLyhttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=174&oldid=prevMirwi at 16:25, 4 January 20172017-01-04T16:25:58Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Optoring_schem.png|center|schematic]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Optoring_schem.png|center|schematic]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The circuit is shown in the schematic above. The diode D2 rectifies the positive portion of the input ringing voltage and charges up the capacitor C3. Of course the negative portion could have been used equivalently, with the diode in correct polarity connected to the negative side of C3. The maximum peak voltage observed at C3, with heavy cranking at a field phone, was about 150V. As a second stage, the capacitor C1 is now slowly charged form C3 trough the resistor R1. Voltage at C3 will rise until the base voltage of Q1, generated from C3 voltage through the divider formed by R2 and (R3+R8), is high enough to make Q1 conduct and turn on M1. The moment M1 turns on, there is a significant amount of current that starts flowing through the LED D1 and R8. The now present voltage drop over R8 will additionally feed the base of Q1 and ensures that it stays conducting until the LED current has subsided. C1 will quickly discharge into the LED, making it flash very briefly, for about 2ms, but with high brightness. When C1 voltage has fallen and the LED current has also decreased, Q1 is no longer conducting and M1 also will <del class="diffchange diffchange-inline">have returned </del>to non conducting mode. As long as there is still charge in C3, C1 is again charged up via R1 and the next led flash is initiated. The time required for C1 charge up will increase with falling C3 voltage. This results in a continuously slowing down flashing of the LED.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The circuit is shown in the schematic above. The diode D2 rectifies the positive portion of the input ringing voltage and charges up the capacitor C3. Of course the negative portion could have been used equivalently, with the diode in correct polarity connected to the negative side of C3. The maximum peak voltage observed at C3, with heavy cranking at a field phone, was about 150V. As a second stage, the capacitor C1 is now <ins class="diffchange diffchange-inline">"</ins>slowly<ins class="diffchange diffchange-inline">" </ins>charged form C3 trough the resistor R1. Voltage at C3 will rise until the base voltage of Q1, generated from C3 voltage through the divider formed by R2 and (R3+R8), is high enough to make Q1 conduct and turn on M1. The moment M1 turns on, there is a significant amount of current that starts flowing through the LED D1 and R8. The now present voltage drop over R8 will additionally feed the base of Q1 and ensures that it stays conducting until the LED current has subsided. C1 will quickly discharge into the LED, making it flash very briefly, for about 2ms, but with high brightness. When C1 voltage has fallen and the LED current has also decreased, Q1 is no longer conducting and M1 also will <ins class="diffchange diffchange-inline">returne </ins>to non conducting mode. As long as there is still charge in C3, C1 is again charged up via R1 and the next led flash is initiated. The time required for C1 charge up will increase with falling C3 voltage. This results in a continuously slowing down flashing of the LED.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_full.png|<del class="diffchange diffchange-inline">thumb</del>|simulation]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_full.png|<ins class="diffchange diffchange-inline">600px|center</ins>|simulation]] <ins class="diffchange diffchange-inline"><br /></ins></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_blitz.png|<del class="diffchange diffchange-inline">thumb</del>|simulation - single LED flash]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:opotring_sim_blitz.png|<ins class="diffchange diffchange-inline">600px|center</ins>|simulation - single LED flash]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The whole circuit is simulated using LTSpice. The results are shown in the two graphs above. On complete one, where the LED slow down is nicely visible, and a zoom of a single LED flash, where the decrease of <del class="diffchange diffchange-inline">C1 </del>voltage <del class="diffchange diffchange-inline">can be seen</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The whole circuit is simulated using LTSpice. The results are shown in the two graphs above. On complete one, where the LED slow down is nicely visible, and a zoom of a single LED flash, where the <ins class="diffchange diffchange-inline">rapid </ins>decrease of <ins class="diffchange diffchange-inline">LED (D1) current becomes obvious. </ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">The measurement results of the actual built units match pretty well with the simulation. The </ins>voltage <ins class="diffchange diffchange-inline">across R8 is perfectly suited for monitoring the LED current with an oscilloscope..</ins>.</div></td></tr>
</table>Mirwihttps://wiki.chaosvermittlung.de/index.php?title=Tech:Optical_bell&diff=170&oldid=prevMirwi: Created page with "== Opitcal bell == At the GPN16 the plan was to put field phones in all lecture halls, close to the speaker desks. To be allowed to do so, the requirement wa..."2017-01-04T00:17:56Z<p>Created page with "== Opitcal bell == At the <a href="/index.php/Events:GPN16" title="Events:GPN16">GPN16</a> the plan was to put field phones in all lecture halls, close to the speaker desks. To be allowed to do so, the requirement wa..."</p>
<p><b>New page</b></p><div>== Opitcal bell ==<br />
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At the [[Events:GPN16|GPN16]] the plan was to put field phones in all lecture halls, close to the speaker desks. To be allowed to do so, the requirement was that these phones should not disturb any lectures by loud ringing. So the phones were silenced (TODO: link to description) and equipped with the optical ring indicator described below, before deployment.<br />
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[[File:Optoring_schem.png|center|schematic]]<br />
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The circuit is shown in the schematic above. The diode D2 rectifies the positive portion of the input ringing voltage and charges up the capacitor C3. Of course the negative portion could have been used equivalently, with the diode in correct polarity connected to the negative side of C3. The maximum peak voltage observed at C3, with heavy cranking at a field phone, was about 150V. As a second stage, the capacitor C1 is now slowly charged form C3 trough the resistor R1. Voltage at C3 will rise until the base voltage of Q1, generated from C3 voltage through the divider formed by R2 and (R3+R8), is high enough to make Q1 conduct and turn on M1. The moment M1 turns on, there is a significant amount of current that starts flowing through the LED D1 and R8. The now present voltage drop over R8 will additionally feed the base of Q1 and ensures that it stays conducting until the LED current has subsided. C1 will quickly discharge into the LED, making it flash very briefly, for about 2ms, but with high brightness. When C1 voltage has fallen and the LED current has also decreased, Q1 is no longer conducting and M1 also will have returned to non conducting mode. As long as there is still charge in C3, C1 is again charged up via R1 and the next led flash is initiated. The time required for C1 charge up will increase with falling C3 voltage. This results in a continuously slowing down flashing of the LED.<br />
[[File:opotring_sim_full.png|thumb|simulation]]<br />
[[File:opotring_sim_blitz.png|thumb|simulation - single LED flash]]<br />
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The whole circuit is simulated using LTSpice. The results are shown in the two graphs above. On complete one, where the LED slow down is nicely visible, and a zoom of a single LED flash, where the decrease of C1 voltage can be seen.</div>Mirwi