relays

Oh, the central point of my argument is that nothing really has power gain, it's just that you can control a power supply with a device. And since a relay switches a power supply, it has gain.

On a sunny day (Thu, 13 Nov 2008 08:10:17 -0800 (PST)) it happened snipped-for-privacy@netzero.com wrote in :

Sure you are right. The Relay was invented by Edison to boost telegraph signals IIRC, so amplify those.

A la*unch nucl*ear wea*pons button has gain.. One light finger press and cities blow up. (Small force controlling a larger force.)

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

Sure. And a latching relay has infinite gain.

John

100mW into a relay can switch 1kW or so, so that's a gain of 10,000, minimum.

Cheers, James Arthur

No, it was probably hydraulic.

John

If you're considering other systems other than electrical, one could make an argument that the first gain element was the lever.

For more complex systems, where power control is involved, there are waterwheels and windmills (particularly the windmill steering mechanisms, which rotated the windmill blade assembly into or out of the wind).

No. It's an impedance transformer, but it has no power gain.

John

Lever.

No power gain directly, but it can be used to control much larger energies, much like the relay example.

Yeah, I remember that, I also recall some clever system to do with "police boxes", and I don't mean a TARDIS. Or was it a fire box? Oh well.

No. Its output energy is less than its input energy. A gain element needs a power supply that's separate from the input signal, and a lever has none.

John

Has no power gain.

John

On a sunny day (Thu, 13 Nov 2008 16:22:30 GMT) it happened Jan Panteltje wrote in :

Oops, it was in 1835 that Joseph Henry invented the relay.

Edison worked on a 'carbon relay' something that became the carbon microphone, some sort of analog pressure contact...

I believe that you are incorrect. Because it can be difficult to differentiate between power gain and power transformation in the face of possible measurement errors, the gold standard for proving that a device has power gain is to make an oscillator out of it. That's how Bardeen and Brattain proved that they had attained semiconductor on December 24th, 1947. Levers and transformers cannot sustain oscillation. Relays, hydraulic valves, vacuum tubes and transistors can.

If I remember correctly, the first demonstration of vacuum-tube oscillation was somewhere around 1910 to 1920, and the first carbon-arc oscillator was developed in the late 1800s.

--
Guy Macon

I was gonna say "whining"--baby bird chirps, momma bird barfs some food down its beak. Huge, but that's a different kind of 'gain.'

Cheers, James Arthur

Attach lever to ox. Whip ox. Ta dah! Power gain... :) /No actual oxen were whipped during this post

Very insightful, thanks.

Well I made a beer gain with my argument. Best kind, really. And I can make myself oscillate with beer. Vacillate, really.