OU/COP>1 switched cap PS cct like Tesla's 'charge siphoning'

[nul-points]

@Magnethos

thanks for the Neg. Res. links


hi Poynt

thanks for your interest in these switched charge experiments

perhaps you can close the loop somehow.

i've shared my thoughts on the limitations and conditionals for the OU behaviour of the switched charge circuit - my experiments continue

I wonder why Dave was not able to get similar results?

if Cap'n P can achieve the basic charge anomaly then anybody can 

Do you have coil construction specs?

i don't believe the coil construction is critical - i usually use a few tens of turns of 0.45mm magnet wire random wound, solenoid-style, on a tubular ferrite core, approx 12mm OD x 30mm, inductance around a few mH, DC resistance probably best between 0.5 - 1ohm, plenty of additional ferrite

home in on the charge anomaly first; then inspect the circuit to reduce losses and maximise energy conversion at the load

On a side note; there are hundreds of SMPS designs out there, and none are ou. How could the development of these designs over all these years not have revealed any anomalies such as what you're seeing?

I can't help feeling that we're missing something.

look at the efficiency of charging a cap, then look at the claimed efficiencies of SMPS systems - something doesn't add up!


BTW i think your Joules Meter is going to revolutionise OU experimentation - you'll probably bring this forum to a standstill 

all the best
s.

[poynt99]

look at the efficiency of charging a cap, then look at the claimed efficiencies of SMPS systems - something doesn't add up!

Could you elaborate?

I see no irregularity in this comparison.

Claimed SMPS efficiencies are around 95%.

I just ran a sim test with your coil (2.5mH, 0.5 Ohm) and two 4.7uF capacitors. Energy transfer n is 93.7%.

Regards,
.99

[Edit]
Actually, the stated efficiency of 93.7% is not quite correct. This would be only for voltage transfer, not energy transfer. The energy transfer efficiency in this case computes to 87.8%.

[nul-points]

hi Poynt

> Quote from: nul-points on December 21, 2008, 10:54:26 PM
> look at the efficiency of charging a cap, then look at the claimed efficiencies of SMPS systems - something doesn't add up!

Could you elaborate?

I see no irregularity in this comparison.

Claimed SMPS efficiencies are around 95%.

yes - claimed efficiency for charging a cap (ie. just that - nothing fancy) is 50%

I just ran a sim test with your coil (2.5mH, 0.5 Ohm) and two 4.7uF capacitors. Energy transfer n is 93.7%.

interesting sim results - is the sim really saying that one cap discharges from 18V to 1V while the second cap charges from 0 to 17V?

all the best
s.

[poynt99]

Sandy,

Yes, the voltages are as denoted in the scope shot.

On an equal playing field (i.e. using an inductor in each case as I stated), the SMPS and simple cap to cap transfer are about the same efficiency, if the values are set correctly. I used 4.7uF caps and your 2.5mH inductor. Transfer is done through a diode in one shot as you can see from the scope shot.

.99

[nul-points]

hi Poynt

your latest sim run very eloquently illustrates my point earlier about the comparison between the claimed efficiency for SMPS and that claimed for charging a capacitor:

when using a series coil & some means of rectifying the charge transfer (eg. diode or switch) to a cap, an SMPS manufacturer can claim 90+% energy efficiency

when supplying current direct to the capacitor (no coils or rectification), the text books claim 50% energy efficiency


as you've seen from the results of the switched charge tests here, it appears that its possible to refine the coil/rectification approach to get up to 150% energy efficiency on a resistive load

all the best
s.