Re-Inventing The Wheel-Part1-Clemente_Figuera-THE INFINITE ENERGY MACHINE

[RandyFL]

Rams,

What is Pulsed DC? The Analog voltmeter which can show both DC and AC voltage readings showed 270 volts. But the digital multimeter showed 220 volt AC and 90 Volt DC. Now Patrick has taught me that pulsed DC is nothing but AC without the negative or bottom wave while Randy says it is DC.

I would stick to transformers and bridge rectifiers...I would also go with what Patrick stated about DC... AC comes in from the mains as a sine wave and goes thru a transformer which either steps up or steps downs or is a 1:1 for special purposes...then thru a bridge rectifier that converts it to just positive ( slices the negative out )...the circuit that Patrick provided... the 12 volt battery powers the 555 ( IC ) oscillates it to pulse 3 volts of square wave ( the variable resistor in the circuit provides a way of increasing the frequency - very handy )...

Gyula
My question is...( because I have never done it ) when you connect an analog Multimeter to rectified DC does the needle go back and forth... LOL ( my assumption is that the needle doesn't have time to swing both ways...)

Also...what is better...clipped off DC from a bridge rectifier or a oscillating half square wave from a 555 ( or arduino or etc.. ) which is more efficient...

[TinselKoala]

It appears that there are some misconceptions forming in this topic.

First, a fullwave diode bridge does not "slice out the negative" of the incoming AC waveform --- see the graphic below. Rather, it takes that negative portion and flips it over to become a positive portion in the output waveform. If the input is "50Hz" then the output will have 100Hz peaks.

Second, the "220VAC" that the wall plug provides is 220 V RMS. This means that the _peak_ voltages are quite a bit higher: about + and - 310 V.
When this is run through an unflitered Full Wave diode bridge, the DC Peaks as shown in the waveform below will be at +310V, minus a little bit for the fed voltage drop of the bridge. An averaging meter will then knock off some more from this value -- 270 volts DC might well be an indicated "average" from this kind of waveform. Once this DC output from the bridge is filtered by capacitors, the voltage will be steady and near the _peak_ value of the AC input... not the RMS value. So it is not surprising that a bridge rectifier can put out DC voltage measurements that are much higher than the "nameplate" voltage input (which will usually be an RMS value.) I think this fully explains the Variac results reported by NRamaswami: nothing unusual happening, just some misunderstandings about FWB action, RMS vs. Peak values, and the averaging functions of meters.

Third... DC pulses most certainly do interact with the inductances of coils. One common form of inductance meter stimulates the coil-under-test with square wave pulses at a given frequency, then looks at the ringdown frequency of the coil's response and computes the inductance from that. If the coil didn't respond to the DC impulses in the first place, this couldn't happen. As long as there is a _change_ in voltage, for example at the leading and trailing edges of a DC pulse, the inductance "feels" this change.

Fourth... what is AC, what is DC? You will find that even trained engineers will argue about this distinction. In my opinion AC requires that the direction of current flow changes, so an oscillating signal must go below the zero baseline level for at least part of a cycle. Others will say that simply oscillating voltage magnitude is enough to call it "AC" even though the current _direction_ may always be going in the same direction, while only the magnitude fluctuates. For example a 5v peak-to-peak sine wave with a 7 volt positive offset would still be called "AC" by this camp. I don't happen to agree with this view myself since the direction of current in such a signal does not change direction.

(EDITED to remove the "wrong" FWB diode diagram! I got that image from the internets and didn't notice it had the diodes mixed up until just now. Sorry about any confusion that might have caused...        )

[RandyFL]

TinselKoala,
Thanks for clarifying the bridge rectifier part...😊...sometimes I just glance at the pictures and keep going...kinda like filling up my car with gas and not knowing how the ICE ( internal combustion engine ) works...

[TinselKoala]

Heh... you should be even more confused... since that silly drawing I got from the Internet doesn't even have the FWB schematic correct! I just noticed this myself...

The waveforms are correct but the diode configuration isn't.

Here's what it should look like:

[RandyFL]

TK,
Oops...sorry I just glanced at it and assumed it was right 😊
How do you feel about transformerless power supplies...