analogizing logic gates

[PG1995]

Hi

How would you analogize logic gates? For example, voltage could be though of as a pressure, transistor could be thought of as device with three gates where middle gate control anything passing thru other two gates, diode could be though as valve which lets flows only in one direction. Perhaps, my examples are not very precise and accurate but you get the idea what I'm after. Thank you.

 

[devilwar]

The idea is really exciting. Never thought like this. I would search for some answers although I dont have any at present. I would also appreciate if you get any answer plz uplod here too. I will be following this post....Cheers mate for such a nice idea...

 

[alexxx]

It looks like you are describing Hydraulic and Pneumatic systems, working with oil (at least the one I have seen) and air respectively. I'm most aware of pneumatics.

Pneumatics - Wikipedia, the free encyclopedia

I haven't work with them since I was a student, but all those components exist. The load was always a pneumatic cylinder and there are components acting as diodes, relays etc. Like voltage difference in electronics, there you are dealing with air pressure difference, using an air compressor to power on the circuit. Cylinder was driven by pneumatic valves. I also remember some electrovalves to be involved, but I'm not sure if they were used in pneumatics or hydraulics. It is really exiting, it also helps you understand DC circuits better, it involves the same phylosophy and way of thinking. Those circuits are met in industrial places where current is dangerous to be used, at least that was what my teachers told me at that time. I am not really an expert on this, I'm just giving you a starting point to search for more.

Hydraulic Pneumatic Circuit Symbols
http://www.freestudy.co.uk/fluid%20power/cylinders.pdf

Regards,
Alexandros

 

[kak111]

**broken link removed**

read all parts.........
Pneumatic Instrumentation - Introduction

Pneumatic Logic & Controls
http://www.normanequipment.com/Brochures/Telepneumatic Lit/PCC-4-PneuLogic&Controls.pdf

Pneumatic logic components
**broken link removed**

Moving part air logic controls
**broken link removed**

Microfluidic Pneumatic Logic Circuits and Digital Pneumatic
Microprocessors for Integrated Microfluidic Systems
http://www.rsc.org/suppdata/lc/b9/b904354c/b904354c.pdf

Microfluidic Pneumatic Logic Circuits and Digital Pneumatic Microprocessors for Integrated Microfluidic Systems
Microfluidic Pneumatic Logic Circuits and Digital Pneumatic Microprocessors for Integrated Microfluidic Systems

 

[BradtheRad]

Hmmm. Logic gates occupy a different world than the analog world where we live with Maybe and Almost and Some.

It may be hard to come up with an ANALOGY for logic gates in this ANALOG world.

Ha ha. (Are you all laughing at that one?)

Back to the question...

When you think about it, a logic gate is a decision maker. It isn't just an on-off switch.

In a sense there might as well be an elf inside the chip saying "Did all the inputs vote Yes? If so then make the output high."

Don't know if that's an adequate analogy.

Because the analogy also ought to hint that a logic gate can be a building block.

A bunch of logic gates can be made into a computer.

One clock cycle trickles through a structure of a million logic gates, causing a change of state here and there.

The next clock cycle changes a few more states.

And we have a magic box that forecasts weather, cleans up scratchy music on our vinyl records, and gives us the internet.

Hard to believe I take it for granted now.

 

[alexxx]

Amazing references you got there kak11!

@BradtheRad: According to those references logic gates could be constructed out of pneumatic components. Of course you are right to wonder what the ultimate goal could be, construct a cylinder drive or a computer...

 

[kak111]

Yet one addition to this thread
In 50´s-70´s automation and control systems generally used
pneumatic and hydraulic components to perform the mathematical functions
Here is examples pneumatic division , multiplication and square-root devices.


PC191 Pneumatic Computing Relay
http://www.foxboro-eckardt.de/pdf/CA_FoxEck/PC191_9CA_A_001_en.pdf

Model 21 Adjustable Ratio Relay
infinite signal multiplication/division over the range of 1:30 to 30:1 by turning a simple adjustment knob.
**broken link removed**
**broken link removed**

Model 557 Pneumatic Square Root Extractor
Square-Root Characterizations
http://resource.invensys.com/instrumentation/documentation/eib/pl/pl_006-346.pdf

Manual : Bailey Mini-Line520 pneumatic computer/controller
http://www.infi90.com/Files/Bailey ...Mini-Line 520 Computer-Controller Type FC.pdf

 

[BradtheRad]

Amazing references you got there kak11!

@BradtheRad: According to those references logic gates could be constructed out of pneumatic components. Of course you are right to wonder what the ultimate goal could be, construct a cylinder drive or a computer...

Yes, I just looked at kak's pneumatic valve references. I had no idea they made such things. They're even called pneumatic logic gates.

There are AND gates, NAND gates, NOR gates, flip flops, oscillators, etc. Made with tubes and air valves.

One assembly even looks as though it starts to approach the complexity of a microprocessor.

And it's an analogy which conveys the binary aspect of logic gates. One extreme or the other. Absence of noise. (These are characteristics which give digital operation a major advantage over analog.)

An analogy is most instructive when our eyes can take it in. Seems like logic gates made with tubes and air valves fills the bill.

I wouldn't be surprised if someone will make (or did make) educational models, made from clear housings so you can see the moving valves.

And it would make a good science fair project. Hands-on visible operating logic gates.