I have been thinking (a dangerous situation.)

There are only 3 passive electronic components:

resistors
Capacitors

 

 

Capacitoes

I've had a toe swell up badly a time or two!

 

I have been thinking (a dangerous situation.)

There are only 3 passive electronic components:

resistors
capacitors
inductors (including mutual)

To these we need to add at least amplifying device, and perhaps a rectifying device.

Then, I believe we can basically do anything an electronic circuit can do.

Remove any of these, and I think we cannot.

First question: is this true?

Second question: are there other hypothetical components that can do the same. Specifically, could we replace resistors, capacitors and inductors with other functions tha do not look much like resistors, capacitors or inductors, and do the same?

I have a gut feeling that these functions are elementary and essential to electronics, and any other components would essentially be a combination of the ones I gave mentioned.

It seems like a resistor is needed to limit current, a capacitor is needed to store energy as a voltage, and an inductor to store energy as a current.

Thoughts?

Bob

 

View attachment 232201

I have a T shirt that says the opposite:

“Resistance is not futile, it is voltage over current.”

Bob

 

You could add to the list:

1. negative resistor
2. gyrator
3. noise generator
4. photon capture device
5. quantum mechanical tunneling device
6. dark matter detector
7. quartz crystal
8. surface acoustic wave device
9. electrochemical cell
10. biochemical cell

.... and so many more.

 

I think a possible alternate cimponent would be a “delayer”, a two terminal device that the voltage on pin 2 is the voltage on pin 1 at t - delay. At least you could make an oscillator with that.

Bob

 

You could add to the list:

1. negative resistor
2. gyrator
3. noise generator
4. photon capture device
5. quantum mechanical tunneling device
6. dark matter detector
7. quartz crystal
8. surface acoustic wave device

.... and so many more.

My list is intended to be minimal, Can you propose a black box that I cannot replicate without those?

Bob

 

How about a photo-voltaic cell for starters?

 

Based on MrChip’s reply, I think I need to clarify the thought experiment a little more.

Let’s talk about a black box containing existing electronic components that has inputs and outputs that are voltages or currents.

I contend that with ideal components that I mentioned, any black box can be replicated, a contention that I do not have a proof for.

The more interesting question is the one about an alternate set of components.

Bob

 

How are you going to replicate a microcontroller?

 

Aha, I have definitely left off one other necessary component. A voltage source. Which can also serve as a voltage reference.

Bob

 

My list is intended to be minimal, Can you propose a black box that I cannot replicate without those?

Bob

Any black box that don't depend on lump-matter assumptions.

EM field effects that break lumped-element assumptions:
The change of the magnetic flux in time outside a conductor is NOT zero.
The change of the charge in time inside conducting elements is NOT zero.
Signal timescales of interest are sizable fraction of propagation delay across the lumped element.

https://courses.edx.org/asset-v1:MI...e@asset+block/handouts_6002-L1-oei12-gaps.pdf

 

In reply to MrChips:

Well, with a BJT or MOSFET as the amplifying device, I don’t think it is too hard.

Bob

 

You could add the galena crystal and extrapolate from that. There has been much conjecture and discussion as to whether to include the Diode as a passive device.

 

Any black box that don't depend on lump-matter assumptions.

EM field effects that break lumped-element assumptions:
The change of the magnetic flux in time outside a conductor is NOT zero.
The change of the charge in time inside conducting elements is NOT zero.
Signal timescales of interest are sizable fraction of propagation delay across the lumped element.

https://courses.edx.org/asset-v1:MI...e@asset+block/handouts_6002-L1-oei12-gaps.pdf

I am talking ideal components here.

Bob

 

You could add the galena crystal and extrapolate from that. There has been much conjecture and discussion as to whether to include the Diode as a passive device.

I did mention a rectifying device, though I am not certain it is needed.

Bob

 

I am talking ideal components here.

Bob

That's what I'm talking about too. The electronic circuit theory assumptions for ideal lumped-element components is a sub-set of EM theory. There are things inside a possible passive 'Black Box' that can't be modeled or build using ideal components if effects in the Black Box depend on the EM effects of matter-space geometry. How do you build a passive microwave magatron cavity from electronic components.

 

Rectification is only one of many uses for a diode...

 

Ohm's law states that the electrical current (I) flowing in a circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

We can classify components and show examples but the equivalent models do not violate ohms law.
When we discuss electron flow it is better to change our approach from conventional current by using an accepted alternate approach.