Can we demonstrate over unity energy?

[forest]

I see you are experts in LtSpice and electronics. Can you help me ? I have one interesting problem to solve electronically . I need advice if it's possible and how.

[partzman]

I see you are experts in LtSpice and electronics. Can you help me ? I have one interesting problem to solve electronically . I need advice if it's possible and how.

Forest,

I'm certainly not an expert but I would be willing to help if possible.  Not all circuitry can be successfully or accurately simulated such as unusual transformer arrangements, non-linear magnetics, etc.  LtSpice does have a good forum on Yahoo with lots of examples, circuits, models, and general help in the use of the software.  There is a help section in LtSpice but it can be rather cryptic for a newb so the forum can really be good source to help understand the commands and features.

Anyway, describe what you need and we'll see if something can be worked out.

Regards,
Pm

[forest]

The issue seems simple and maybe it is , but I'm lost.
How to make electronically DC CURRENT to rise across resistor in triangle wave from some small value (above zero) to the maximum current (directed by Ohm law) and again to small value. I know it can be done using kind of variable power supply (rising and lowering input voltage) but how to make it electronically (not in simulation  but in real circuit) ? Something like DC-DC converter with variable voltage output ? Kind of SCR controlled by triangle signal ?
If not possible I think that quite close output can generate  common emitter transistor amplifier with sine wave signal input - not a triangle current wave but sine but close. Parameters however have to be computed in reverse : we have the maximum current (which is Ohm law based) flowing through the resistor of known value and power source of known DC voltage. Is there a way to find by LTSpice simulation in that situation values of required bias resistors  ?

[lancaIV]

Thanks TK!  The energy is dissipated in the load, circuit switching losses, coil resistances, etc.  Actually DR's circuit is not as inefficient as it appears in the last sim.  If C1 is replaced with a 10ufd cap and the sim is then run until the circuit stabilizes, the COP is ~ .93 and this could be improved upon with mosfet switching and some timing.  Unfortunately it is still conservative.

Regards,
Pm

Hello pm,
#reply 10 COP is .093 ergo less than 10% !
This means 10 times structural optimation to reach COP=1


Sincerely
              OCWL

[partzman]

The issue seems simple and maybe it is , but I'm lost.
How to make electronically DC CURRENT to rise across resistor in triangle wave from some small value (above zero) to the maximum current (directed by Ohm law) and again to small value. I know it can be done using kind of variable power supply (rising and lowering input voltage) but how to make it electronically (not in simulation  but in real circuit) ? Something like DC-DC converter with variable voltage output ? Kind of SCR controlled by triangle signal ?
If not possible I think that quite close output can generate  common emitter transistor amplifier with sine wave signal input - not a triangle current wave but sine but close. Parameters however have to be computed in reverse : we have the maximum current (which is Ohm law based) flowing through the resistor of known value and power source of known DC voltage. Is there a way to find by LTSpice simulation in that situation values of required bias resistors  ?

OK, the most efficient solution would be to use PWM or pulse width modulation.  This is the technique that most if not all class D audio amplifiers use to achieve high power with high efficiency.  Basically, a high frequency square wave oscillator has it's duty cycle modulated by a lower frequency source and a low pass filter is then used on the output to attenuate the high frequency.  In your case, this low frequency would be a positive triangle wave but it could be any wave shape unipolar, bipolar, or complex as in music content. 

There are really low cost class D amplifier pcb modules available from China thru Ebay which would be cheaper and easier than trying to build your own.  You would then only need to provide the power supply and input signal in the wave shape of your choice and connect the load.  IIRC, I have purchased 100w class D stereo modules in the past for ~$15.00 and free shipping.

Hope this helps,
Pm