A few weeks ago I finally figured out the common standard ordinary mainstream textbook theory what makes the Tesla-switch so interesting.
Then yesterday I watched a presentation by Peter Lindemann where he mentioned the Bedini SSG generator-mode.
After some calculations I came up with the following COP for some different SSG-modes:
Std SSG: 50%
Gen Mode: 66%
Ossie/TS Mode: 75%
Mixed Mode: 80%
A short presentation of the theory:
https://www.youtube.com/watch?v=fo1RsJ0ym2Y (https://www.youtube.com/watch?v=fo1RsJ0ym2Y)
A previous video comparing Std SSG vs Ossie/TS Mode in a real life experiment:
https://www.youtube.com/watch?v=_eh5pQpNsGM (https://www.youtube.com/watch?v=_eh5pQpNsGM)
/Hob
Thank you for sharing,
very interesting circuits.
I too am working on simple circuits to find the principle we are looking for.
All the best
dave
Quote from: Dave45 on November 04, 2014, 05:22:21 PM
Thank you for sharing,
very interesting circuits.
I too am working on simple circuits to find the principle we are looking for.
All the best
dave
In the left hand circuit the top diode just wastes power and serves no useful purpose. Ditto the bottom diode in the right hand circuit.
In the left hand circuit, the bottom diode is reverse biased, IE off when the NPN transistor is on. No current flows through the right hand battery. When the NPN transistor turns off, the coil discharges through the diode and the right hand battery. You can make the circuit much more efficient by putting a driver in front of the NPN transistor to switch it off quickly and changing the diode to either a Schottky type or a synchronous rectifier.
I wonder what "COP" you get in MHOP mode.
Meanwhile, Dave and Mark try this little circuit. You'll get a "kick" out of analyzing it, I'm sure. It's the circuit of the Perpendupetulum, and runs off bright room lighting onto a solar cell.
I don't know why C2 is so large. Otherwise it looks like a lot of other harvesting devices.
Wouldn't it be better to pump current into the battery instead of voltage, or how about both.
Quote from: TinselKoala on November 04, 2014, 07:14:11 PM
I wonder what "COP" you get in MHOP mode.
Meanwhile, Dave and Mark try this little circuit. You'll get a "kick" out of analyzing it, I'm sure. It's the circuit of the Perpendupetulum, and runs off bright room lighting onto a solar cell.
Whats interesting is where the pull up resistor is connected.
Does it get hit with pos and then neg.
I wonder how fast it turns on and off.
Current flow follows electron flow, this is why the current doesnt just run to ground.
This causes a cycling through the inductor and diode.
The triggered pulses are pretty short, 25 ms or so.
The circuit in action:
http://www.youtube.com/watch?v=0dMPQs5vpek
Texas we have resonance!
Quote from: TinselKoala on November 04, 2014, 10:04:38 PM
The triggered pulses are pretty short, 25 ms or so.
The circuit in action:
http://www.youtube.com/watch?v=0dMPQs5vpek (http://www.youtube.com/watch?v=0dMPQs5vpek)
Too Cool
Bro I have to say you do good work.
Quote from: TinselKoala on November 04, 2014, 07:14:11 PM
I wonder what "COP" you get in MHOP mode.
Isn't MHOP about how to trigger the switch rather than where the switch (and the rest) is in the circuit?
/Hob
Quote from: nilrehob on November 05, 2014, 01:34:42 AM
Isn't MHOP about how to trigger the switch rather than where the switch (and the rest) is in the circuit?
/Hob
That's mostly true, although there is a little finesse in the output side as well. But yes, it is still your basic lowside switch arrangement.
The MHOP's sense/trigger system gives the operator full control over dwell and timing, and the optional strobe circuit lets the user know the timing and dwell without the use of external instruments like a scope. The coil polarity can be reversed by a switch, so it's easy to change from an attraction-type to a repulsion-type PM without complicated reconfiguring, and the power take-off and recirculation bits have options too. The recirculation, for example, uses 2 neons, one each to the positive and negative poles of the run battery.
Quote from: Dave45 on November 04, 2014, 11:04:00 PM
Too Cool
Bro I have to say you do good work.
Thanks! I'm learning, right along with the rest of us.
Trying out a variant, seemed like a fun thing to try and make, thanks for sharing TK!
Pic of my (second) attempt; used an LED instead of the diode and I added a 331 potentiometer on the positive input instead of a 330 ohm resistor.
Okay, back to lurking... ;)
Phi Chaser
Where's your coil?
Very nicely done!
I don't know what the LED will do in place of the diode, though; I got better performance (according to my definition of "better" i.e. lower voltage operation) when I changed from the 1n4148 / 1n914 type switching diode to the 1n5817 Schottky.
Also, try the LED across the coil in both orientations. In either orientation, if there is too much voltage on the input this LED will light up, but when the device is working "properly" (again, by my definition) this LED will only show tiny flashes.
My coil measures about 11 mH and 36 ohms DC resistance. Around 900 turns of #33 on a small bobbin, air core of course.
The coil I have tried is quite a bit larger I think; 30mm diameter,25mm tall, 62.5mH and 51.6ohms resistance (500+turns of 32? no idea... came out of a shake flashlight). I will post a shot when I get it working properly. Without any battery I can put a neo in the coil and get the main LED to flash when I pull it out of the coil, if done quickly the second LED will eventually start a low flicker.
Some things that I have found interesting; I can get the (main LED) flash if connecting the coil to both ends of the positive rail. I can also get the flash when connecting the coil from the neg input to the pos output (but not the other way around).
I might end up putting that diode back in... I don't have any Schottky diodes.
Phi Chaser
EDIT: For lack of pnp transistors I built another using three parallel caps (2220uf total) and a spot where I can test 'stuff'. I did find a germanium pnp transistor and it let one of the LEDs stay lit for a little while... Uploaded a pic of my second build.
Should this pendulum circuit be a new thread d'ya think?
The shake flashlight coil is kind of large in inner diameter isn't it? And I found that my build works best with a coil that is nearer 10 or 11 mH and 30-40 ohms. I made a bigger one, around 75 ohms, and it works to pulse OK once the pendulum is swinging, but can barely trigger, so it is very difficult to self start. The one in the videos is closer, and I made a third one that is even closer to 10 mH and 30 ohms and it seems to work the best.
I think that for the pendulum you may want to wind a coil of smaller inside diameter, to focus the field more tightly over the end. The original Nuts&Volts article specified a bobbin, and I actually found the spec sheet for the exact bobbin. I made my own of almost the same size out of a section of phenolic tube 1/4 inch ID and some end plates cut from thin plastic or phenolic sheet.
Bobbin spec drawing below: (inch dimensions, sorry)
Yep, the inside of my coil is about 1/2" (inches, mms, whatever works!), I took a closer look and it is probably closer to 1000 turns. The neo fits neatly inside the coil so I figured it would probably work okay for the pendulum...
Thanks for the dimensions on the coil you are using, I will see about winding something that has a smaller inside diameter (closer to the specs) and see if that works better.
Hopefully I can figure out some sort of stand to hang the weight and mount the coil on so I can actually 'watch' it working...
I need to order some parts or go find another 'something' to take apart for pieces'; seems like all I have are npn transistors and I'm running low on caps...
PC
I got my BC556B PNPs from a seller called "thaishine" on Ebay, I've dealt with them several times and am quite happy. Free shipping to US addresses, four days from order to delivery in my mailbox. $3.49 for 50 transistors, delivered! They also respond to emails right away for confirmation, etc.
Search for
"ebay thaishine bc556b"
If you are outside the USA or can wait longer, I see listings for 50 at under two dollars, with a dollar shipping, coming from mainland China or Hong Kong.
Yep, you are going to need a suspension for your pendulum to see the real operation of the circuit, or make a small rotor to try it as a rotary pulse motor. You could probably make a linear version too, with the right magnets and suspension.
One strand for output from a bifilar power coil, looped back to source, should produce some valuable coasting time.
@TinselKoala: I watched your pendulum videos and wonder, why the pendulum stays exactly above the coil.
I know that the pendulum is suspended exactly above the coil. But the pendulum should try to avoid the coil, specially in push mode.
Or is the pendulum in attraction mode, which would always pull the swinging magnet over the centre of the coil core?
Great build!
I got the BC557B instead of the BC556B (which has a lower collector-base voltage -50V instead of -80V, and a lower collector-emitter voltage -45V instead of -65V, the rest of the spec is pretty much the same). Should it also work with the BC557B?
Greetings, Conrad
Quote from: conradelektro on November 07, 2014, 11:14:15 AM
@TinselKoala: I watched your pendulum videos and wonder, why the pendulum stays exactly above the coil.
I know that the pendulum is suspended exactly above the coil. But the pendulum should try to avoid the coil, specially in push mode.
Or is the pendulum in attraction mode, which would always pull the swinging magnet over the centre of the coil core?
Great build!
I got the BC557B instead of the BC556B (which has a lower collector-base voltage -50V instead of -80V, and a lower collector-emitter voltage -45V instead of -65V, the rest of the spec is pretty much the same). Should it also work with the BC557B?
Greetings, Conrad
The pendulum is suspended by a "V" suspension so it only swings in one plane. It's hard to see this in the video, I'm sorry I didn't emphasise it. The two points at the top are 10 cm apart and the vertical height from suspension to magnet is 20 cm. I adjust spacing by raising/lowering the coil, which is just sitting on a plastic 1/4-20 flathead screw with a plastic nut under the coil. Screw head is glued to the baseboard, coil is raised and lowered by the nut. 3 or 4 mm space between magnet and top of coil. The system operates in repulsion, when the drive pulse happens it pushes the magnet away. The suspension's geometry is such that any disturbance winds up being coupled into the plane of the swing, so it doesn't have to be perfectly accurate in position above the magnet to self-start. As usual, try all four combos of magnet and coil polarity to get best performance with triggering and pulsing.
I guess that the BC557 transistor should work fine as well. The original circuit specified 2n4401 and 2n4403.
Thanks for checking it out! It is really a fascinating little toy, I have it running constantly on the light from the desk lamp which is on anyway. I stop it and let it selfstart every now and then. If it doesn't get a trigger pulse from the passing magnet, it pulses automatically every few seconds, which is how it self-starts.
ETA: If there is too much voltage supplied, the coil will stay on. Also the LED (in my build) should make only tiny, short, barely visible flashes when it is running properly. Also, try the LED both ways, see what happens.
Quote from: TinselKoala on November 07, 2014, 04:52:15 PM
The pendulum is suspended by a "V" suspension so it only swings in one plane.
@TinselKoala: Thank you for clarifying the suspension of the pendulum.
I see, the capacitor C2 1000µF provides a pulse every now and then for the self start.
I just have to build one. As you say, very very neat.
The circuit reminds me of the two transistor circuit for a pulse motor (which does not need any separate trigger means, because the Back-EMF of the drive coil provides the trigger):
https://www.youtube.com/watch?v=OqQSJjRJ6EQ
Greetings, Conrad
Experimental update at:
https://www.youtube.com/watch?v=7MhPPuYuGwc (https://www.youtube.com/watch?v=7MhPPuYuGwc)
/Hob
This is my multi-mode circuit I use for easier comparison:
https://2f0f5746-a-62cb3a1a-s-sites.googlegroups.com/site/nilrehob/home/documents/SSG modes COP experiment.png (https://2f0f5746-a-62cb3a1a-s-sites.googlegroups.com/site/nilrehob/home/documents/SSG%20modes%20COP%20experiment.png)
/Hob
Below are the functions of the switches.
/Hob
Quote from: nilrehob on January 04, 2015, 03:36:04 PM
Below are the functions of the switches.
/Hob
Very nice, I like your approach. Live comparisons are the best kind.
But which combination is the "OU" combo? ;)
Quote from: TinselKoala on January 04, 2015, 05:48:13 PM
But which combination is the "OU" combo? ;)
The one in Peters and Arrons book ::)