CODE PRACTICE OSCILLATOR powered by any computer MIC JACK - no batteries needed - EVER -

Every computer MICROPHONE INPUT jack,  has its own voltage and current that is already built inside it, in order to power Electret Mics.  By modifying a very simple and low voltage square wave generator circuit to make use of this MIC VOLTAGE, a very simple and NO BATTERY NEEDED -  EVER -   code practice oscillator can be made using this circuit, the MIC JACK,  and  an AUDIO to MIDI technique to regenerate the original input cw tone from this LM3909 and convert it to an amazing sine wave shaped cw note.

 

 Here is the circuit used for this:

 

- HERE IS WHAT THIS OSCILLATOR SOUNDS LIKE -

Just like it sounds with no filtering and then by using AUDIO to MIDI technique to regenerate the tone

Views: 395

Tags: AUDIO to MIDI, LM3909, code practice oscillator, css555, sineCW, software CPO

Comment by Chuck aa0hw on February 24, 2014 at 4:34pm

HERE IS A VIDEO SHOWING A SIMILAR SETUP USING A MICRO POWERED LOW VOLT 555 CHIP

This video demonstrates an experimental setup for powering a CODE PRACTICE OSCILLATOR css555 MICRO POWER, LOW VOLTAGE TIMER circuit from just the voltage and current available at any sound card MIC JACK. This example is for a STEREO MIC jack. [ This technique will also work on a mono jack too, but the MONO MICROPHONE /css555 circuit is different and will be demonstrated in a follow up video later on in this series. ] The micro power and low voltage mode of the css555 timer chip is the key ingredient in this stereo mic powered CPO CIRCUIT. You are able to hook as many keyers, bugs, straight keys, etc, all at the same time, to this circuit to key this CPO. AUDIO to MIDI is used to regenerate the cw tones. A 15khz output tone from the css555 is utilized for maximum performance from the REAGATE VST PLUG for AUDIO to MIDI technique which outputs midi NOTE ON and NOTE OFF data, precisely duplicating the original length of the dits and dahs from the keyer(s) output, also pitch midi messages are delivered to the software CPO - SATYR, that is keyed by these midi messages.

NOTE: the voltage measurements on my mic jack were 2.2 volts - no load, and 1.6 volts with this circuit engaged in a "key down" condition.

HERE ARE THE LINKS MENTIONED IN THIS VIDEO:
1. css555 from JAMECO
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001...
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?lang...
http://www.jameco.com/Jameco/Products/ProdDS/2158733.pdf
2. Data sheet for the css555
http://www.customsiliconsolutions.com/downloads/Revised%20Standard%...
3. previous videos for AUDIO to MIDI setups for generating a cw sidetone:
A. https://www.youtube.com/watch?v=h0nmo3FlHxA
B. https://www.youtube.com/watch?v=OPeYsPfjPqg
C. https://www.youtube.com/watch?v=FavCoF8IIG4
D. https://www.youtube.com/watch?v=2B47s1_WXbo
3. SATYR VSTi PLUGIN
http://www.vstplanet.com/News/10/Satyr.htm
4. AUDIO to MIDI - REAGATE PLUGIN
http://www.kvraudio.com/product/reagate_by_cockos
http://www.reaper.fm/reaplugs/
5. JACKROUTER VIDEO DEMO
https://www.youtube.com/watch?v=h883l3PUJ50

Comment by Chuck aa0hw on December 3, 2014 at 1:57pm

A low power TLC555 timer chip works for the MIC POWERED CPO


An experiment with a TLC 555 low power timer chip proved to be successful in working in this circuit. This circuit is powered only by the internal voltage of the MICROPHONE INPUT JACK of a laptop.

I also hooked up a scope and tested how much the voltage could be lowered and see that there was still output from the 555 chip oscillator....I was able to go down as low as 1.1 volts to work with the TLC 555...it might be worth trying this TLC 555 chip first,  before purchasing the CSS555.

HERE ARE THE BASICS on the TLC 555 data chip

HERE IS A VIEW OF THE 10khz 555 INPUT and the 700 hz SINE WAVE SHAPED CW OUTPUT

MPowerSynth creates a very clean spectrum for QRQcw morse code audio tones

Comment by Chuck aa0hw on February 17, 2015 at 11:22am

HERE IS THE LATEST VERSION OF THE css555 CIRCUIT


click on diagram to enlarge to full page view 

- The 10 F cap stores the 2.5 volts from the mic jack power, acts like a small battery pack

- The 1 Henry inductor keeps PIN 3's output from being grounded through the power supply of the circuit

- The freq of this css555 CPO circuit is 20khz, which gets converted to a 700 hertz sinewave sidetone by the AUDIO TO MIDI software VST PLUGINs - REGATE and sineCW

- The current drain of this circuit using the "stock unprogrammed css555" or the TLC555 is around 250 uA.  The maximum current that my mic jack can sink using both TIP and RING in parallel( stereo mic ) is about 850 uA.  The 10 F cap supplies most of the current to the circuit during keydown, and during keyup...the CAP will recharge slowly back to @ 2.4 volts.

Here is a picture of the css555 20khz waveform which goes to the computer sound card's mic jack input in order to be converted to a 700 hertz sine wave CPO by REAGATE and sineCW VST PLUGINs.

With different cap/resistor values you can of course modify this circuit to generate any audio frequency.  I am choosing 20khz for optimal results for regenerating the cw elements using AUDIO to MIDI conversion.

I thought it was interesting that this css555 circuit produces a sinewave instead of a square wave.  Here is a picture of the audio spectrum analysis of this circuit showing one predominant frequency at @20khz.

The AUDIO to MIDI conversion is extremely accurate in its timing and reproducing exactly the same length of the original cw elements and the spacing between them.  Here is an example of a test stream of fast dits keyed from my LOGIKEY K1 KEYER, which keys the css555 circuit just like it would key a rig and the resultant dit lengths and space between dits are exactly the same on all of them.

Here is what the cw looks like after the AUDIO to MIDI conversion  -  very accurate regenerative cw

Here is the first AUDIO to MIDI plugin used for the cw regenerative conversion process - REAGATE

Here is the actual plugin that is generating the MORSE CODE AUDIO TONES with adjustments for RISE and FALL time,  post bandpass filter settings to minimize key clicks and edge noise - sineCW

Here is the audio spectrum analysis of sineCW 

all this audio DSP processing is done in software using a VST HOST like MINIHOST MODULAR

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