Comments - Ultra PicoKeyer : tips for connecting it to your computer sound card - QRQcw2024-03-29T09:10:47Zhttps://qrqcwnet.ning.com/profiles/comment/feed?attachedTo=1993813%3ABlogPost%3A23763&xn_auth=noAdding a Straight Key to your…tag:qrqcwnet.ning.com,2016-08-08:1993813:Comment:265252016-08-08T19:01:54.909ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p style="text-align: center;"><strong>Adding a Straight Key to your UltraPico Keyer computer interface</strong></p>
<p style="text-align: center;"><span style="text-align: left;">Using a micro powered <a href="http://www.jameco.com/z/CSS555-ID-Custom-Silicon-Solutions-CSS555-Micropower-Timer-DIP-8_2146433.html" target="_blank">CSS555</a> chip and the simplest 555 oscillator circuit design as described here: …</span></p>
<p style="text-align: center;"><strong>Adding a Straight Key to your UltraPico Keyer computer interface</strong></p>
<p style="text-align: center;"><span style="text-align: left;">Using a micro powered <a href="http://www.jameco.com/z/CSS555-ID-Custom-Silicon-Solutions-CSS555-Micropower-Timer-DIP-8_2146433.html" target="_blank">CSS555</a> chip and the simplest 555 oscillator circuit design as described here: </span><a href="http://www.555-timer-circuits.com/simplest-555-oscillator.html" target="_blank" style="text-align: left;">555</a></p>
<p style="text-align: center;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127152455?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127152455?profile=original" width="406" class="align-full"/></a></p>
<p style="text-align: center;"></p>
<p style="text-align: left;">We add this css 555's output to the "other" audio channel of the stereo MIC jack input. A stereo jack "doubler" audio adapter is used to bring the MIC JACK's stereo ports to both the UPK and the css555 circuit as you see on the breadboard. The UPK will use the LEFT MIC JACK CHANNEL to charge its 10F cap, and the CSS555 will use the RIGHT MIC JACK CHANNEL to charge its 10F cap. The UPK uses the RT MIC JACK CHANNEL to send its sidetone audio output through a .047 uF cap. The CSS555 uses the LEFT MIC JACK CHANNEL to send its sidetone audio output through a .047 uF cap.</p>
<p style="text-align: center;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127152583?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127152583?profile=original" width="648" class="align-full"/></a><strong>Here is a close up of the breadboard</strong></p>
<p style="text-align: center;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127152999?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127152999?profile=RESIZE_1024x1024" width="750" class="align-full"/></a></p>
<p style="text-align: left;">CHARGING THE 10 F CAP: the green wire, from the MIC JACK CABLE, is going through a diode to charge the 10 F cap from one of the MIC JACK's stereo channels; the one not being used for charging the UPK's 10 F cap.</p>
<p style="text-align: left;">NOTE: not shown on schematic is the 100k RESISTOR to ground for pin 4 that you see in this picture just above. We toggle pin 4 to the POSITIVE voltage in order to activate the CSS555 into "sending mode" using the ST KEY. The current drain on the CSS555 is only 3 to 4 uAMPS in standby mode. KEY DOWN on PIN 4 TO POS, will only increase the current drain to @ 100 uAMPS during transmit mode on this CSS555.</p>
<p style="text-align: left;">By using a variable 5 megaohm POTENTIOMETER and/or 365p VARIABLE CAP, you can vary the SIDETONE AUDIO PITCH very smoothly. </p>
<p style="text-align: left;">(<em>This css555 circuit produces a square wave that will need to be filtered or regenerated</em>)</p>
<p style="text-align: left;"></p>
<p style="text-align: left;">HERE IS A PICTURE of the original css555 sidetone output waveform on top to the filtered on bottom:</p>
<p style="text-align: left;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153039?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127153039?profile=original" width="669" class="align-full"/></a></p>
<p style="text-align: left;"></p>
<p style="text-align: left;"></p>
<p style="text-align: left;">HERE is a picture of the spectrum output of the css555 output before and after bandpass filtering:</p>
<p style="text-align: left;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153469?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127153469?profile=RESIZE_1024x1024" width="721" class="align-full"/></a></p>
<p style="text-align: left;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127155133?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127155133?profile=RESIZE_1024x1024" width="721" class="align-full"/></a></p>
<p style="text-align: center;">HERE IS THE cw audio BANDPASS FILTER being used:</p>
<p style="text-align: center;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127155359?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127155359?profile=RESIZE_1024x1024" width="721" class="align-full"/></a></p>
<p style="text-align: center;">and HERE is what the ST KEY and PADDLES sound like with this setup</p>
<p style="text-align: center;"><iframe width="560" height="315" src="https://www.youtube.com/embed/gSKGLqWJ17E?wmode=opaque" frameborder="0" allowfullscreen=""></iframe>
</p>
<p style="text-align: left;"></p>
<p style="text-align: left;"></p> Here is a picture of the fina…tag:qrqcwnet.ning.com,2016-04-25:1993813:Comment:239252016-04-25T14:36:50.386ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p style="text-align: center;"><strong>Here is a picture of the final voltage and charging current once the SuperCap reaches full charge after a few days of charging from the MIC JACK power supply</strong></p>
<p style="text-align: center;"><strong><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=original" target="_self"><img class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=RESIZE_1024x1024" width="750"></img></a> <strong>Here is a picture of the final voltage and charging current once the SuperCap reaches full charge after a couple more weeks…</strong></strong></p>
<p style="text-align: center;"><strong>Here is a picture of the final voltage and charging current once the SuperCap reaches full charge after a few days of charging from the MIC JACK power supply</strong></p>
<p style="text-align: center;"><strong><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=RESIZE_1024x1024" width="750" class="align-full"/></a><strong>Here is a picture of the final voltage and charging current once the SuperCap reaches full charge after a couple more weeks of charging from the MIC JACK power supply</strong><br/></strong></p>
<p style="text-align: center;"><strong><strong><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127155318?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127155318?profile=RESIZE_1024x1024" width="721" class="align-full"/></a></strong></strong></p>
<p style="text-align: center;">And below is another picture showing that after 3 hours of holding down the dit paddle handle for a continuous dit stream test, after the SUPER CAP had reached the 2.568 volts as pictured just above, the voltage dropped down to only 2.157 volts and the CAP charging current only went up to 45 uAmps.</p>
<p style="text-align: left;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127156820?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127156820?profile=RESIZE_1024x1024" width="721" class="align-full"/></a>This 10 FARAD cap works fantastic as a battery eliminator - that even after 3 hours of steadily holding down the dit paddle handle, the voltage/storage capacity of the 10 FARAD SUPER CAPACITOR has barely dropped (only 4 tenths of a volt) and the MIC JACK POWER SUPPLY charging current is still under 50 microamps.(the INTERNAL MIC POWER SUPPLY can sink about 600 uAmps per channel)</p>
<p style="text-align: center;"></p> The Ultra Picokeyer setup for…tag:qrqcwnet.ning.com,2016-04-24:1993813:Comment:239242016-04-24T21:32:04.919ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p style="text-align: center;"><strong>The Ultra Picokeyer setup for your MAC computer will work with the same setup as Windows 10</strong></p>
<p style="text-align: center;"><strong><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/wJr0q6QBKvo?wmode=opaque" width="560"></iframe>
</strong></p>
<p style="text-align: center;"><strong>Here is a screenshot…</strong></p>
<p style="text-align: center;"></p>
<p style="text-align: center;"><strong>The Ultra Picokeyer setup for your MAC computer will work with the same setup as Windows 10</strong></p>
<p style="text-align: center;"><strong><iframe width="560" height="315" src="https://www.youtube.com/embed/wJr0q6QBKvo?wmode=opaque" frameborder="0" allowfullscreen=""></iframe>
</strong></p>
<p style="text-align: center;"><strong>Here is a screenshot</strong></p>
<p style="text-align: center;"><strong><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127152802?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127152802?profile=RESIZE_1024x1024" width="750" class="align-full"/></a></strong></p>
<p style="text-align: center;"></p>
<p style="text-align: center;"><strong>CARLA</strong>(<em>jack audio connection bay</em>) and <strong>Mbandpass filter</strong> have MAC versions too as you see above</p>
<p style="text-align: center;">you can download jackOSX from the same website: <a href="http://jackaudio.org/downloads/" target="_blank">http://jackaudio.org/downloads/</a></p>
<p style="text-align: center;">El Capitan version - JackOSX.0.92_b3.zip - <a href="https://github.com/jackaudio/jack2/issues/73" target="_blank">https://github.com/jackaudio/jack2/issues/73</a></p>
<p style="text-align: center;">take a look at jackpilot here: <a href="http://www.jackosx.com/about.html" target="_blank">http://www.jackosx.com/about.html</a></p>
<p style="text-align: center;">Mbandpass filter has versions for MAC : <a href="https://www.meldaproduction.com/MBandPass" target="_blank">https://www.meldaproduction.com/MBandPass</a></p>
<p style="text-align: center;">KXstudio's CARLA jack connection bay for MAC here: <a href="http://kxstudio.linuxaudio.org/Downloads" target="_blank">http://kxstudio.linuxaudio.org/Downloads</a></p> Here is a video tutorial show…tag:qrqcwnet.ning.com,2016-04-17:1993813:Comment:238222016-04-17T10:11:44.019ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p style="text-align: center;"><strong>Here is a video tutorial showing how to have a morse code qso from one UltraPico Keyer CW OP to another UltraPico Keyer CW OP over the internet using just your CHROME BROWSER(WebRTC)</strong></p>
<p style="text-align: center;"><strong><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/gcufFg0J4Fk?wmode=opaque" width="560"></iframe>
</strong></p>
<p style="text-align: left;"><span>Using just your CHROME BROWSER,…</span></p>
<p style="text-align: center;"><strong>Here is a video tutorial showing how to have a morse code qso from one UltraPico Keyer CW OP to another UltraPico Keyer CW OP over the internet using just your CHROME BROWSER(WebRTC)</strong></p>
<p style="text-align: center;"><strong><iframe width="560" height="315" src="https://www.youtube.com/embed/gcufFg0J4Fk?wmode=opaque" frameborder="0" allowfullscreen=""></iframe>
</strong></p>
<p style="text-align: left;"><span>Using just your CHROME BROWSER, WebRTC will allow you to use your UltraPico Keyer sidetone with your computer sound card to have a morse code qso over the internet with another CW OP using a similar setup.</span><br/><br/><span>Source-Connect Now, in this setup example, provides the WebRTC function via the CHROME BROWSER. This works on windows, mac and linux if you have the Chrome Browser.</span><br/><br/><span>LINKS:</span><br/><span>Source-Connect Now</span><br/><a href="https://now.source-elements.com/#!/" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://now.source-elements.com/#!/</a><br/><span>Melda free Mbandpass VST PLUGIN</span><br/><a href="https://www.meldaproduction.com/MBandPass" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://www.meldaproduction.com/MBand...</a><br/><span>Calf filter</span><br/><a href="http://calf-studio-gear.org/" class="yt-uix-sessionlink" rel="nofollow" target="_blank">http://calf-studio-gear.org/</a><br/><br/><span>JACKROUTER FOR WINDOWS 10</span><br/><a href="https://youtu.be/zzd7naKzRgw" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://youtu.be/zzd7naKzRgw</a><br/><span>SYNCHRONOUS AUDIO ROUTER</span><br/><a href="https://youtu.be/l-U1rEz4K38" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://youtu.be/l-U1rEz4K38</a><br/><span>JACKROUTER FOR LINUX</span><br/><a href="https://youtu.be/GBD-wsMiZCk" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://youtu.be/GBD-wsMiZCk</a><br/><a href="https://youtu.be/-ky2WJEZnxU" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://youtu.be/-ky2WJEZnxU</a><br/><span>JACKROUTER FOR MAC</span><br/><a href="https://youtu.be/R9ctwPgoal0" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://youtu.be/R9ctwPgoal0</a><br/><span>NOTE: FOR MAC</span><br/><span>use this free virtual audio cable</span><br/><a href="https://github.com/mattingalls/Soundflower" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://github.com/mattingalls/Soundf...</a><br/><span>melda's MBandpass filter is also for MAC </span><br/><a href="https://www.meldaproduction.com/download/plugins" class="yt-uix-sessionlink" rel="nofollow" target="_blank">https://www.meldaproduction.com/downl...</a><br/><br/><span>BASIC SETUP </span><br/><br/><span>CW OPs send their UPK SIDETONE into the mic input or line input jack of their sound card. Using jackrouter, the audio from the mic or line input is routed to a bandpass filter plugin. After it has been filtered, the audio is routed to two points... THE COMPUTER SOUND CARD SPEAKERS/headphones so you can monitor your sidetone in real time, AND at the same time, the output of the bandpass filter is routed over to a "virtual audio input" that directly connects with the input to Source-Connect Now and then over to and through the internet to the other UPK CW OP.</span><br/><br/><span>FULL DUPLEX - fast break-in - low latency - is possible with WebRTC and Source-Connect Now. In this same QRQcw youtube channel there are other videos that go over the jackrouter and Synchronous Audio Router setup</span></p>
<p style="text-align: center;">NOTE: this setup also works well with the voice chat APP - Mumble - for a qso on the iCW server.</p>
<p style="text-align: center;"><a href="https://sites.google.com/site/icwoip/" target="_blank">https://sites.google.com/site/icwoip/</a></p>
<p style="text-align: center;"><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127152378?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127152378?profile=original" width="360"/></a></p> Here is a REVISED version of…tag:qrqcwnet.ning.com,2016-04-11:1993813:Comment:237692016-04-11T15:31:39.265ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p>Here is a REVISED version of the schematic and some circuit mods shown to place everything on the original Ultra PicoKeyer circuit board. <strong> </strong></p>
<p style="text-align: center;"><strong>- <em>click on pictures for full size view -…</em><br></br></strong></p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127150832?profile=original" target="_self"><img class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/3127150832?profile=RESIZE_1024x1024" width="750"></img></a></p>
<p style="text-align: center;"></p>
<p>Here is a REVISED version of the schematic and some circuit mods shown to place everything on the original Ultra PicoKeyer circuit board. <strong> </strong></p>
<p style="text-align: center;"><strong>- <em>click on pictures for full size view -</em><br/></strong></p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127150832?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127150832?profile=RESIZE_1024x1024" width="750" class="align-full"/></a></p>
<p style="text-align: center;"><span style="text-decoration-line: underline;"><strong>MODS</strong></span></p>
<p style="text-align: center;"><strong>Here is the FRONT of the UPK BOARD</strong> </p>
<p style="text-align: left;">On the front of the board the <strong>10 FARAD ULTRACAP</strong>(2.5 volts) is soldered into place to the + and - power supply pins at the edge of the board.(the battery holder & the speaker are unsoldered and removed in order to make room for the <a href="https://www.sparkfun.com/products/746?gclid=CJ3A-6P2hswCFQMQaQodalYKYg" target="_blank">2.5 VOLT UltraCap</a>)</p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127151031?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127151031?profile=RESIZE_1024x1024" width="750" class="align-full"/></a></p>
<p></p>
<p>HERE IS THE BOTTOM OF THE BOARD where you have to break the copper traces between the left and right headphone jack pathways and the UPK CHIP to the headphone jack pathway and then solder in a .047uF cap. Also shown is a connection from the POSITIVE RAIL of the incoming mic input cable (RT CHANNEL) to the POSITIVE pin of the UPK POWER SUPPLY/supercap(through the 1n914 diode). Also a wire connects from the MIC INPUT CABLE(UPK HEADPHONE JACK OUTPUT) GROUND to the UPK negative pole of the power supply pin where the SUPERCAP is soldered, connecting the grounds between the HEADPHONE JACK ground and the UPK main circuit board ground.(in the original schematic of the UPK this ground is normally isolated via a CAP, but we need the grounds to "dc" connect in order to make use the power supply from the computer mic jack to trickle charge/recharge the UltraCap to 2.5 volts.</p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127151098?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127151098?profile=original" width="543" class="align-full"/></a></p>
<p></p>
<p>HERE IS A CLOSE UP of the new solder points and circuit trace "breaks" near the UPK headphone jack output</p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127151050?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127151050?profile=original" width="744" class="align-full"/></a></p>
<p></p>
<p>THIS VIEW HIGHLIGHTS WHERE THE NEW SOLDER POINTS and TRACE BREAKS are located:</p>
<p>the red circles are the solder points, and the red horizontal lines are where the trace breaks have been carved into the board by a box knife and triangular file.</p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153254?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127153254?profile=RESIZE_1024x1024" width="721" class="align-full"/></a></p>
<p></p>
<p>HERE IS AN VIEW FROM ABOVE OF THE MOD'd UPK BOARD and the COMPUTER MIC INPUT </p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127155288?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3127155288?profile=original" width="665" class="align-full"/></a></p>
<p></p>
<p>THE 10 FARAD CAP now will act like a battery supply and provide all the voltage and current needed to operate the UPK KEYER for as long as you need it to operate. During periods of NON USE and KEY UP, the MICROPHONE POWER SUPPLY will trickle charge(< 1 ma) the 10 FARAD SUPER CAP back to 2.5 volts.</p>
<p>NOTE: on my laptop STEREO microphone power supply, the voltage is @2.9 volts on both the left and right channels...the 1N914 diode knocks the mic voltage down to @2.5 volts. (measured after 2 days of trickle charging) </p>
<p>MEASURE YOUR MICROPHONE VOLTAGE and verify that it is no more than 3 VOLTS...and also to see if you have a STEREO or MONO MIC on your computer before attempting these mods to your UPK. If your mic voltage measures more than 3 volts, lower it by adding more diodes in series until the charging voltage matches the VOLTAGE RATING of your UltraCap... usually either 2.5 or 2.7 volts.</p>
<p><strong>NOTE:</strong> Although this version shows a <strong>10 F</strong>arad supercap, a <strong>1 F</strong>arad supercap may be sufficient. I have never run out of "juice" when using a <strong>1 F</strong>arad supercap during any of my cw qso's. The <strong>10 F</strong>arad takes many hours more to get to full charge with only the MIC JACK providing the power source compared to a <strong>1 F</strong>arad supercap. If you jump start the charging of the supercap with an external power source, make sure not to exceed the voltage rating of the supercap(2.5 or 2.7 volts) and it may be best to use a current limiting resistor...@5 to 10 ohms. I have used 2 d cells(3 volts) and pre-charged the supercap to 2 volts and then allowed the mic jack to the do the rest. My UPK starts working once the supercap reaches a 1.6 volt charge. Its nice to hear the UPK send out its 73 cw sidetone alert message, once the UPK supercap power supply charges up enough to reach its "critical mass" for START UP.</p>
<p style="text-align: center;"><strong>HERE IS A VIDEO TUTORIAL COVERING THIS BATTERY ELIMINATOR CIRCUIT</strong></p>
<p style="text-align: center;"><strong><a href="https://youtu.be/5-f0iSwMQAw" target="_blank"><iframe width="560" height="315" src="https://www.youtube.com/embed/5-f0iSwMQAw?wmode=opaque" frameborder="0"><strong><a href="https://youtu.be/5-f0iSwMQAw" target="_blank"></a></strong><p></p>
<p style="text-align: center;"></p>
<p style="text-align: center;">Here is the final voltage and charging current once the SuperCap reaches full charge</p>
<p style="text-align: center;"></p>
<a href="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/3127153466?profile=RESIZE_1024x1024" width="721" class="align-full"/></a><p></p>
</iframe>
</a></strong></p> Here is an experimental batte…tag:qrqcwnet.ning.com,2016-04-08:1993813:Comment:237132016-04-08T15:25:10.424ZChuck aa0hwhttps://qrqcwnet.ning.com/profile/chase
<p style="text-align: center;"><strong>Here is an experimental battery eliminator circuit for the Ultra PicoKeyer.</strong></p>
<p style="text-align: center;"><em>click on picture for full size view</em></p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127150931?profile=original" target="_self"><img class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/3127150931?profile=RESIZE_1024x1024" width="750"></img></a></p>
<p></p>
<p>Since I am using the STEREO MIC JACK of the computer soundcard, and both channels of the STEREO MIC JACK already have a built in power supply of around…</p>
<p style="text-align: center;"><strong>Here is an experimental battery eliminator circuit for the Ultra PicoKeyer.</strong></p>
<p style="text-align: center;"><em>click on picture for full size view</em></p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/3127150931?profile=original" target="_self"><img width="750" src="http://storage.ning.com/topology/rest/1.0/file/get/3127150931?profile=RESIZE_1024x1024" width="750" class="align-full"/></a></p>
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<p>Since I am using the STEREO MIC JACK of the computer soundcard, and both channels of the STEREO MIC JACK already have a built in power supply of around 2.9 volts that can deliver about 600 microamps per channel, (@1.2 milliamps total) to charge the <strong>1</strong> <strong>F</strong>ARAD SUPER CAP, the UPK will run for a long time easily on the 2.5 volts from the fully charged <strong>1 F</strong>ARAD SUPER CAP(~<em>2.5 volts</em> <em>due</em> <em>to the voltage drop from the diodes</em>), and then you never have to worry about batteries. The UPK will continue to work perfectly down to about 1.6 volts, but even after a long qso, and due to the continuous recharging by the mic voltage energy harvesting circuit during receive(<em>key up</em>), the voltage on the SUPER CAP never dropped below 2 volts. The charging current into the <strong>1 F</strong>ARAD SUPER CAP is also limited by the "dc" resistance of the 100 mH CHOKE COIL.(<em>the choke coil helps to keep the output signal of the UPK from going back to ground through the super cap.)</em></p>
<p><strong>WARNING:</strong> MEASURE YOUR MIC VOLTAGE FIRST ! - to make sure that your mic voltage is <strong>3 volts or less</strong>...or you could damage the UPK CHIP , if your mic jack is more than 3 volts, knock it down by adding more diodes in series until it matches your 2.5 volt or 2.7 volts UltraCap rating.</p>