Incoming links: Transistor
Main implementations: the same as electronic switches: vacuum tubes in the past, and transistors in the second half of the 20th century.
How to make an LM386 audio amplifier circuit by Afrotechmods (2017)
Source. Builds the circuit on a breadboard from minimal components, including one discrete transistor. Then plays music from phone through headset cables into a speaker.600 Mountain Ave bldg 5, New Providence, NJ 07974, United States.
Became headquarters in 1967,
Drone footage: www.youtube.com/watch?v=z0Ld2KFjaC8 Bell LABS Headquarters Murray Hill NJ in 4K Drone Flight by ESTOUCHFPV (2017)
Notable inventions made there:
- the first transistor
- TODO confirm C
This notation is designed to be relatively easy to write. This is achieved by not drawing ultra complex ASCII art boxes of every component. It would be slightly more readable if we did that, but prioritizing the writer here.
Two wires are only joined if but the following are:
+ is given. E.g. the following two wires are not joined: |
--|--
| |
--+--
|Simple symmetric components:
-,+and|: wireAC: AC source. Parameters:e.g.:Hz: frequencyV: peak voltage
If only one side is given, the other is assumed to be at a groundAC_1Hz_2VG.C: capacitorG: ground. Often used together withDC, e.g.:means applying a voltage of 10 V across a 10 Ohm resistor, which would lead to a current of 1 ADC_10---R_10---GL: inductorMICROPHONE. As a multi-letter symmetric component, you can connect the two wires anywhere, e.g.or:---MICROPHONE---| MICROPHONE |SPEAKERR: resistorSQUID: SQUID deviceX: Josephson junction
Asymmetric components have multiple letters indicating different ports. The capital letter indicates the device, and lower case letters the ports. The wires then go into the ports:
D: diodeSample usage in a circuit:a: anode (where electrons can come in from)c: cathode
Can also be used vertically like aany other circuit:--aDc--We can also change the port order, the device is still the same due to capital| a D c |D:--cDa-- | Dac-- | Dca-- | --caDDCDC source. Ports:E.g. a 10 V source with a 10 Ohm resistor would be:p: positiven: negative
If only one side is given, the other is assumed to be at a the ground+---pDC_10_n---+ | | +----R_10------+G. We can also omitpandmin that case and assume thatpis the one used, e.g. the above would be equivalent to:If the voltage is not given, it is assumed to be a potentiometer.DC_10---R_10---GT: transistor. The ports aresgTd:Sample usage in a circuit:s: sourceg: gated: gate
All the following are also equivalent:---+ | --sgTd--| g --sTd-- | --Tsgd-- |I: electric current source. Ports:s: electron sourced: electron destination
V: Voltmeter. Ports:If we don't need to specify explicit positive and negative sides, we can just use:p: positiven: negative
without any ports. This is notably often the case for AC circuits.---V---Optionaly, we can also add the sides as in:
Numbers characterizing components are put just next to each component with an underscore. When there is only one parameter, standard units are assumed, e.g.:means:Micro is denoted as
+-----+
| |
C_1p R_2k
| |
+-----+- a capacitor with 1 pico Faraday
- a resistor with 2 k Ohms
u.Wires can just freely come in and out of specs of a component, they are then just connected to the component, e.g.:means applying a voltage of 10 V across a 10 Ohm resistor, which would lead to a current of 1 A
DC_10---R_10---GElectromagnets allow us to create controllable magnetic fields, i.e.: they act as magnets that we can turn on and off as we please but controlling an input voltage.
Compare them to permanent magnet: on a magnet, you always have a fixed generated magnetic field. But with an electromagnet you can control the field, and even turn it off entirely.
This type of "useful looking thing that can be controlled by a voltage" tends to be of huge importance in electrical engineering, the transistor being another example.
The Story of John Bardeen at the University of Illinois (2010)
Source. - youtu.be/OyV8qSwGUHU?t=976 of when Bardeen demoed the transistor in class is particularly memorable
- youtu.be/OyV8qSwGUHU?t=1105 some of his golf colleagues didn't know he had won a Nobel Prize!
- youtu.be/OyV8qSwGUHU?t=1260 good jokes about receiving the second Nobel Prize
Congratulations on the second prize. With the third you get to keep the king!
The king asked my mother [Bardeen's son speaking]: "Where's he family"? The mother answered: "Well, they're at home or school". And the kind replied: "Well, next time, bring them!"