Back Pulse Current Generator

[joellagace]

Hello all. I have been experimenting  with various methods despite negative controversy regarding some of these methods. I am most interested in Back EMF and Tesla's work. Specifically the shorting effects of a tuned L/C circuit. I'm not an expert. I just experiment for fun and the curiosity. And more then once using these methods as inspiration has lead me to find something. What ever that something is.

I would like to share my latest Youtube video of my latest prototype. I'm going to try and explain as crude as I know it. Perhaps others can fill the blanks if they don't like my explanation. Not an expert here!

So this one. I use a motor speed controller module as a source of pulse. This one pulses at 50 hz. I saw others on here use more simple methods using a 555 timer IC as a pulse generator feeding a coil collecting back EMF with help of rectifying diode and capacitor back to DC. So with that said back to my project.  I than connect it to 9 volts DC battery source. I got small amp meter connected in series to the module watching the device draw less then 20ma to operate. Since i'm not actually driving a motor with it. It is not taking much current to do the job. What looks like a regular transformer is just a kit module I had handy laying around for a coil source of back EMF. The transformer is connected almost like a regular AC. How ever I set it up so the pulses only go in one direction so that can easily rectify the back pulse with a diode. So the ground side of the transformer is really connected to battery ground and not the pulsed - port. Various experiments lead me to see that using a transformer via back EMF instead of the traditional step up via primary and secondary winding. That it works better current wise. Like stepping up these pulses to crazy high voltages leads to a big current drop. The drop is no where near as apparent using back pulse of coil instead. So more efficient. With that said. Operating in this configuration. With the help of the motor speed step control knob, I can mess around with the waveform and see on the oscilloscope screen the effects. Just at the right spot. The circuit draw less then 20ma and on the Back pulse rectified side generates over 45ma. How ever. A slight change of waveform setting and this effect diminishes. Both meters show around the same current input then output even perhaps more input then out so not very efficient at all. But there is this "Sweet spot" where this seems to be happening. Granted i'm not going to power a hospital any time soon with this micro power. But it seems to show me that there is something worth while exploring out there.

Here is a video of it working with the meters so you can see for yourself.

https://youtu.be/ACi7689vvqA

And here is another video of a similar device but this was one of my first experiments. It back feed the pulses into the circuit and kept a big capacitor charge from dropping fast as the whole thing ran fine for half a day without batteries off its own back EMF pulses. Powering a few LEDS and even a speaker playing a tone.

https://youtu.be/vwHELGIw60w


This is very interesting stuff as every experiment I seem to be finding something worth while investigating. Please don't bash I'm just learning and sometimes It's pure trail and error.
looking forward to hearing your thoughts.

[e2matrix]

What is your voltage in and voltage out ?   It's easy enough to increase current output from the input value with nothing more than a transformer.   So unless you are calculating watts as I assume you know ( voltage x current ) an increase in current output doesn't say much.   Nice work though and you may have something there in that window where a resonance is happening.  Nice to have those lab kits.   Picked one up myself not long ago for $10 at a garage sale - barely used and it seems all the parts are still with it. 

[forest]

Can you draw a schematic ?

[joellagace]

What is your voltage in and voltage out ?   It's easy enough to increase current output from the input value with nothing more than a transformer.   So unless you are calculating watts as I assume you know ( voltage x current ) an increase in current output doesn't say much.   Nice work though and you may have something there in that window where a resonance is happening.  Nice to have those lab kits.   Picked one up myself not long ago for $10 at a garage sale - barely used and it seems all the parts are still with it.

It might, or I should say probably have something do do with resonance.  As moving my body around it while working seems so slightly alter the readings. Putting my hands in between some of the wiring even. And it only happens at a specific setting, You can see on the scope that moment of off time then more pulses in a group then some off time again spaced evenly repeating the cycle. When I move the control knob to a point that the waveform is always pulsing so does the increase of current on both ends seem even at a little over 100ma in and out.

I just did the experiment again real quick as it is still setup. I checked the voltage on the output side and it is 2.5 volts output at 47ma, with input voltage of 9 volts with input current of  just under 10ma. I'm not that great at math does that tell you anything? So 9 X 0.010 = 0.09 input and 2.5 X 0.047 = 0.1175 output or around there?  It varies somewhat as I move my hand around so it is difficult to get an exact number I got in the video!

[endlessoceans]

It might, or I should say probably have something do do with resonance.  As moving my body around it while working seems so slightly alter the readings. Putting my hands in between some of the wiring even. And it only happens at a specific setting, You can see on the scope that moment of off time then more pulses in a group then some off time again spaced evenly repeating the cycle. When I move the control knob to a point that the waveform is always pulsing so does the increase of current on both ends seem even at a little over 100ma in and out.

Hi Joel

Happy experimenting!

1)  What E2matrix said needs to be addressed.  Focussing on current is no better than mentioning voltage alone.  So whats the entire picture?  and it also depnds on the load that you are charging.
Playing with BEMF is where much of this forum started (with the blocking oscillator or joule thief).  If I understand your explanation and have the schematic clear in my mind, what you have there is basically a joule thief which can output modest efficiency.  Where you are placing the 'load' and measuring just means a little less loss.  Nothing new here.  The sweet spot is the resonant point and because you are using a pulser its not very dynamic and can easily drift in and out of resonance.  Resonance will always create higher efficiency because the pulses are not fighting themselves so to speak.

2)  your last post about moving your hand around and it changing things is more of the same.  The circuit is radiating and losing energy as it operates.  Your body acts as a larger grounded capacitor and you touching things is going to change the operational frequency.

Using a pulser is very frustrating because everything is always drifting.  Better to build a self resonant circuit that doesn't have finicky tuning issues

All being said what you have there is just a flyback rudimentary circuit which helps understand some of the principles of how oscillators work.