Bedini's Linear Current Amplifier

[Nityesh Schnaderbeck]

The beta multiplier is a Gyrator circuit, it uses a small capacitance to simulate a large inductor (without the backemf), so the beta multiplier is like a choke. (a big coil in series).

Changing the voltage to the base of the beta multiplier, is changing the output voltage at the emitter of the beta multiplier..

If you had 10 watts available in the pre-filter cap, you can chose to have it served as "10V @ 1A" or "1V @ 10A" according to the controlling voltage to the base of the beta multiplier.

The beta multiplier and the pre-filter cap, make a power source with adjustable impedance. So you can adjust your voltage current ratio.

Because the beta multiplier is an inductance simulator, this provides a very high impedance to high frequency's, so they don't pass through.

The radiant spikes are now allowed to charge the pre-filter capacitor, without getting loaded, only the DC component is allowed to pass the beta multiplier.

The impedance of the battery is sensed, and a special feedback voltage, (that represents the battery impedance), is fed to the beta multiplier, this achieves automatic impedance matching. Between the beta multiplier and the battery, for maximum power transfer.

The command voltage (set by your voltage adjustment), sets the impedance/voltage threshold, of what the battery charges to.

[Nityesh Schnaderbeck]

Hey all,
I believe it is the PNP we need to use to feed the battery, i don't know that it needs to be a darlington pair maybe, if you go to
http://www.allaboutcircuits.com/videos/74.html by the example of the op amp internal circuit. the v+ power feed comes in and runs through a single PNP. the professor sz its a transistor being used as a resistor to control current pick up the video around 1:15. The PNP is being used as a resistor for current. Mr Bedini shows the amplifier circuit feeding the battery, and he draws out a op amp on the white board.
don't we want that circuit to regulate the current, the Beta circuit is controlling the voltage..... and providing the current(not controlling)

In the following video http://www.allaboutcircuits.com/videos/74.html the pnp transistor, that he says is being used as a resistor, is part of a circuit known as a current source http://en.wikipedia.org/wiki/Current_source. A current reference instead of a voltage reference. A current source is used to stabilize, the differential amp, resistor networks, and many other circuits.

A current source is a current regulator, there are many designs for current sources. By the way it can be a pnp transistor or npn transistor current source.

You could have some thing here, maybe the output transistor circuit is a kind of current source.


By the way "Ecancanvas" I really like how your circuits are neat and tidy, nice work.

[Nityesh Schnaderbeck]

you still need the darlington....


Tom C

Yes, a darlington, There must be a reason why these are the same transistor. 2 of the same transistor. Notice how bedini has the 2 transistors that make up the beta multiplier, on the same heatsink.

And guess what this means, if you need thermal coupling between the transistors, then the characteristics of the transistors must need be the same, with changes in temperature.

I say this because only 1 of these transistors will be getting hot, and will be heating up the other transistor to maintain identical characteristics, to keep the transistors a matched pair.

Conclusion The 2 transistors of the beta multiplier, is a matched pair

[Nityesh Schnaderbeck]

Hey all,
I believe it is the PNP we need to use to feed the battery, i don't know that it needs to be a darlington pair maybe, if you go to
http://www.allaboutcircuits.com/videos/74.html by the example of the op amp internal circuit. the v+ power feed comes in and runs through a single PNP. the professor sz its a transistor being used as a resistor to control current pick up the video around 1:15. The PNP is being used as a resistor for current. Mr Bedini shows the amplifier circuit feeding the battery, and he draws out a op amp on the white board.
don't we want that circuit to regulate the current, the Beta circuit is controlling the voltage..... and providing the current(not controlling)

The only reason the Output transistor is darlington is because the op-amp cannot drive enough current to control a power transistor directly, and uses a small transistor to control a bigger one (the power output transistor).

But if you had an output transistor with enough current gain. Then there would be no reason for the output transistor to be a darlington.

[Nityesh Schnaderbeck]

so the low output impedance of the emitter follower goes on the back end to allow maximum current into the battery or load correct? So all we need to do is swap out that pnp darlington pair with an npn power transistor and add some emitter resistance then connect the charge battery in parallel across the emitter resistance. But that will cause the battery to want to discharge through that emitter resistance but that is where the output is from an emitter follower is according to the above link....so confused!

The emitter resistor is a voltage source. Converts the current, flowing though it to a voltage.
If it was 12V across the emitter resistor, the circuit would not know the difference if this resistor was replaced with a 12V battery (12V battery in series with a resistor)

[Ecancanvas]

The impedance of the battery is sensed, and a special feedback voltage, (that represents the battery impedance), is fed to the beta multiplier, this achieves automatic impedance matching. Between the beta multiplier and the battery, for maximum power transfer.

So its kind of like power factoring with a cap-bank to bring into harmonics both sources of power. This minimizes the waist of energy and promotes the best power transfer?

The Gyrator circuit follows what John Bedini said about having just the right cap on the base of the Beta multiplier to set the current. So in the circuit we are working on,the feedback resistors R9,R13and R16 are effecting voltage between R3 and R6. and from other post we want that voltage to be double the charging battery voltage?

Thanks Nityesh, Lots of things to experiment with to find the answers.

Thanks Tom for chipping in. I know you probably know Johns circuit, so i hope you keep us from going down the wrong path. I'm not after duplicating Mr Bedini's circuit, but i sure want to duplicate his results, and the only way we are going to do that is to keep learning and experimenting.
This is a fun project.
Cheers

[Nityesh Schnaderbeck]

In power supply regulator design you need at least one stable non varying, voltage reference.

Lots of power supply's can be turned into adjustable ones by adjusting the reference voltage.

So now I am only going to use the voltage regulators as a balanced adjustable voltage reference. Here is my schematic, first I will get this working, this will be my experiment base.

Any attempt of me to connect the feedback to the voltage regulators, only makes my voltage reference unstable. Resulting in very strange voltage adjustment, like non linear.

development base.pdf

Once I have nice stable voltage reference, I will have a stable circuit.

I can add on from this.

Then I will turn the balanced voltage reference, into an unbalanced voltage reference using an op-amp.






This op-amp drives the output device.
The feedback is taken from the output device, and fed into an input of the op-amp via the feedback resistor. So to achieve negative feedback.

At this stage I will have a regulated single rail adjustable voltage, power supply from 1.25V to 15V with current. Then once this is working, I can add on.

[Nityesh Schnaderbeck]

So its kind of like power factoring with a cap-bank to bring into harmonics both sources of power. This minimizes the waist of energy and promotes the best power transfer?

The Gyrator circuit follows what John Bedini said about having just the right cap on the base of the Beta multiplier to set the current. So in the circuit we are working on,the feedback resistors R9,R13and R16 are effecting voltage between R3 and R6. and from other post we want that voltage to be double the charging battery voltage?

Thanks Nityesh, Lots of things to experiment with to find the answers.

Thanks Tom for chipping in. I know you probably know Johns circuit, so i hope you keep us from going down the wrong path. I'm not after duplicating Mr Bedini's circuit, but i sure want to duplicate his results, and the only way we are going to do that is to keep learning and experimenting.
This is a fun project.
Cheers

It could be that the beta multiplier is an adjustable simulated inductor, which is connected is series with the pre-filter cap. And does it have a resonance frequency.

[Nityesh Schnaderbeck]

Here is the next stage, to make an adjustable single rail power supply 1.25V to 15V.

development base2.pdf

Once this is working correctly as an adjustable power supply from 1.25V to 15V. Then I/we can add on. Then to figure out the impedance sensing and feedback circuits.

R11 will need to be adjusted/trimmed so that op-amp ground is exactly half voltage of the beta multiplier output, Maybe around 5K.

R1, R2, Q3, Q4, LED1 and C2 is the clamping circuit, and it is supposed to waste power. If someone made this circuit with a big machine, and they disconnect the battery while the machine is running, then the clamping circuit could be clamping a couple of amps or so.

When the "linear amp regulator" is loaded, and the pre-filter cap is below 30V, the clamping circuit does nothing at all, so the only thing doing the smoothing is the capacitor at the base of the beta multiplier.

Then this is working as a Gyrator, it is transforming the capacitance at the base of the beta multiplier, into a simulated inductance, that is choking the high frequency pulses. The high frequency radiant pulses can charge the pre-filter cap, without getting loaded, only the DC component is allowed to pass.

The clamping circuit only stops the base of the beta multiplier from raising above 30V.

"Ecancanvas" I like how you changed R1 to 5.6K, this will save the zener. The zener is a weak link, so protect this.

If you get the datasheet for the zener, it will tell you what the best biasing current is, from this the resistors can be calculated.

"Ecancanvas" you have figured out the impedance sensing of the battery without knowing it. I could not really understand the phrase "The emitter resistor that balances the emitter", unless it is a current source..

If the output device was a current source, then the battery voltage would be a function of the impedance. Because the current is held as a constant value (current reference). The voltage drop across the battery, will vary in order to keep the current constant. (current regulator)

And the battery voltage will indicate the impedance. Just like how a current source can measure a resistor.

The beta multiplier will know the battery impedance, so super cool.

[Nityesh Schnaderbeck]

This schematic now has a current source for impedance sensing

linear amp regulator2.pdf

R11 will need to be adjusted/trimmed so that op-amp ground is exactly half voltage of the beta multiplier output, Maybe around 5K.

[Ecancanvas]

"Ecancanvas" you have figured out the impedance sensing of the battery without knowing it. I could not really understand the phrase "The emitter resistor that balances the emitter", unless it is a current source..

Glad to be your Muse, Ill reconfigure the circuit i have bread boarded to follow along and test your new adaptations.

[Nityesh Schnaderbeck]

Here is a schematic that uses a PNP current source as the output device.



linear amp regulator2-pnp.pdf

Both NPN and PNP variations can be tested, so we can find out what is the best.

[Joster]

Nityesh,

Awesome work..I suppose I was alittle early laying out a pcb board for this haha...looks like you have things fleshed out now quite well. Would you say i could go ahead and order the parts for this first prototype now?

[Nityesh Schnaderbeck]

Nityesh,

Awesome work..I suppose I was alittle early laying out a pcb board for this haha...looks like you have things fleshed out now quite well. Would you say i could go ahead and order the parts for this first prototype now?

If you have the inspiration to do this don't hold back, and have lots of fun.

[Nityesh Schnaderbeck]

The current that passes through the beta multiplier is the same current that flows though the output device and the battery, because these are connected in series.

For the battery to see the same impedance as it'sellf the voltage needs to be double, with the same current.

R10 sets the current regulation, if there is too much current, it will drag the voltage of the pre-filter cap to less than double, so R10 needs to be set so it does not drag down the voltage of the "linear amp regulator." to less than double.

The beta multiplier gyrator and pre-filter cap is a power source with adjustable impedance, because the current is held constant, the voltage of the beta multiplier becomes a function of the impedance, just like with the battery.