TheAnalogThing - User contributions [en]

Initial conditions

2025-01-23T11:04:51Z

Marco-Guerini: Created page with "'''Initial Conditions''' are voltages used to, effectively, determine the precise solution of a differential equation."

'''Initial Conditions''' are voltages used to, effectively, determine the precise solution of a differential equation.

Capacitor

2025-01-23T10:52:19Z

Marco-Guerini: /* Capacitors in THAT */

A '''Capacitor''' is one of the fundamental four passive electronic components, together with Resistors, Inductors and Memristors.

It's widely used in Analog computers as the key element in the [[Integrator]], [[Track & Store Circuit]] and as stabilizer in uncommitted or [[Open Amplifiers]].

It is capable of storing a certain amount of electrical charge (measured in Coulombs) depending on a propriety called Capacitance. The larger the capacitance, the larger the amount of charge stored and longer the time needed to charge.

An analogy useful to understand capacitor behaviour is by comparing it to a bucket. The larger in volume the bucket, the longer the time to fill it by a pipe carrying so many liters per second. The amount of water is definite and proportional to the volume of the bucket itself. The bucket can also be emptied instantly, akin to how capacitors can discharge instantly by being short-circuited.

== Basics of Capacitors ==

A capacitor in its most basic form is created by putting two metal plates, called armatures or simply 'plates' facing each other.

== Usage in Analog Computers ==

First and foremost, Capacitors can be defined as the 'heart' of the [[Integrator]].
By taking a simple [[Summer]] and taking out its feedback resistor, which has a linear relationship betwixt current and voltage (I = V/R, ''Ohm's Law''), and substituting it with a capacitor an integrator is obtained.
The relationship between current and voltage in a capacitor is, in fact, I = C*(dV/dt) and shows a time-dependent behaviour which leads, eventually, to the normal Integrator transfer function. For more details, see the related [[Integrator]] page.

Second, capacitors are used in Track & Store circuits.

A track and store circuit uses the capacitor to "memorize" a signal at a certain point in time, effectively saving it.

== Capacitors in THAT ==

THAT possess a number of capacitors, either uncommitted or internal to the integrators.

The uncommitted (free) ones are five in number, three 100 picofarads and two 100 nanofarads. These are used to either convert an [Open Amplifier] to an integrator, or to help stabilize an open amplifier used to implement inverse functions.
Usually, the stabilization effect is accomplished using the smaller 100pF capacitors, leaving the 100nF ones to be used as feedback elements for additional integrators.

The capacitors internal to the [integrators] are 1nF and 100nF. Normally, the 1nF is connected across to produce a [Beta] of (1M x 1nF = 1000 (RC product being 10^-3). By instead jumpering the output across the ''Slow'' contact, a Beta of 10 is obtained. Of course, the actual value of the feedback capacitor in that case would be 101nF, but it's precise enough for THAT's educational, qualitative scope.

Capacitor

2025-01-23T10:51:51Z

Marco-Guerini: Added THAT cap infos and usage

A '''Capacitor''' is one of the fundamental four passive electronic components, together with Resistors, Inductors and Memristors.

It's widely used in Analog computers as the key element in the [[Integrator]], [[Track & Store Circuit]] and as stabilizer in uncommitted or [[Open Amplifiers]].

It is capable of storing a certain amount of electrical charge (measured in Coulombs) depending on a propriety called Capacitance. The larger the capacitance, the larger the amount of charge stored and longer the time needed to charge.

An analogy useful to understand capacitor behaviour is by comparing it to a bucket. The larger in volume the bucket, the longer the time to fill it by a pipe carrying so many liters per second. The amount of water is definite and proportional to the volume of the bucket itself. The bucket can also be emptied instantly, akin to how capacitors can discharge instantly by being short-circuited.

== Basics of Capacitors ==

A capacitor in its most basic form is created by putting two metal plates, called armatures or simply 'plates' facing each other.

== Usage in Analog Computers ==

First and foremost, Capacitors can be defined as the 'heart' of the [[Integrator]].
By taking a simple [[Summer]] and taking out its feedback resistor, which has a linear relationship betwixt current and voltage (I = V/R, ''Ohm's Law''), and substituting it with a capacitor an integrator is obtained.
The relationship between current and voltage in a capacitor is, in fact, I = C*(dV/dt) and shows a time-dependent behaviour which leads, eventually, to the normal Integrator transfer function. For more details, see the related [[Integrator]] page.

Second, capacitors are used in Track & Store circuits.

A track and store circuit uses the capacitor to "memorize" a signal at a certain point in time, effectively saving it.

== Capacitors in THAT ==

THAT possess a number of capacitors, either uncommitted or internal to the integrators.

The uncommitted (free) ones are five in number, three 100 picofarads and two 100 nanofarads. These are used to either convert an [Open Amplifier] to an integrator, or to help stabilize an open amplifier used to implement inverse functions.
Usually, the stabilization effect is accomplished using the smaller 100pF capacitors, leaving the 100nF ones to be used as feedback elements for additional integrators.

The capacitors internal to the [integrators] are 1nF and 100nF. Normally, the 1nF is connected across to produce a [Beta] of '''(1M x 1nF = 1000 (RC product being 10^-3)'''. By instead jumpering the output across the ''Slow''' contact, a Beta of 10 is obtained. Of course, the actual value of the feedback capacitor in that case would be 101nF, but it's precise enough for THAT's educational, qualitative scope.

Capacitor

2025-01-23T10:41:45Z

Marco-Guerini: /* Usage in Analog Computers */

Inverter

2024-12-31T19:34:00Z

Marco-Guerini: Reworded a few things

Inverters are one of the basic computing elements of an analog computer. They provide '''sign reversal''' of their single input ([[wiki:Additive inverse|Additive inverse]] for real numbers). Mathematically, an inverter performs <code>OUT = -IN</code>. [[The Analog Thing]] features four inverters, laid out in column on the right of the main panel.

== Simple use of an Inverter ==
[[File:Inverter.png|thumb|A single inverter]]

Connect a single input line to the <code>1</code> input. Do not stack multiple input jacks as only a single input signal is allowed (A workaround is possible, see below). At the output, you can stack any number of connector plugs as needed.

== Using an inverter as a summer ==
Together with a [[XIR]], an inverter can be used as a fully featured [[Summer]]. To do so, connect the <code>SJ</code> (Summing Junction) jacks of both elements and then use the weighted inputs of the XIR as you would do with a normal Summer.

[[Category:Components of The Analog Thing]]

XIR

2024-12-31T19:21:09Z

Marco-Guerini: Added link to SJ page

[[File:Xir.png|thumb|A single XIR element]]

The XIR element stands for '''Resistor array''' and is actually more of a ''electrical low level'' building block for an analog computer. It has a number of inputs with different weights which are translated to currents at the [[Summing Junction|summing junction]]. This way, you can extend [[Integrator]]s, [[Summer]]s or [[Inverter]]s with more inputs. To do so, just connect the summing junctions of the respective elements.

The resistor between "SJ" and "1" is 1 MOhm, and the resistor between "SJ" and "10" is 100 kOhm.

The picture to the right is from an older version of THAT. The current THAT version doesn't have a 0.1 input. However if you need a 0.1 input, you can connect your input signal via a 10 MOhm resistor to the SJ input, or alternatively via a 9 MOhm resistor to a "1" input.

The cable from SJ of the XIR block to SJ of the integrator, summer or inverter may receive interference from other cables. Try to make this cable as short as possible, and away from other cables. If this doesn't help, you can slow down the integrator, summer or inverter by connecting a 100pF capacitor between the output and SJ input.

== Examples ==
{{todo|provide some wiring examples}}

[[Category:Components of The Analog Thing]]

Oscilloscope

2024-12-30T15:41:37Z

Marco-Guerini: added CRT alternative

An '''Oscilloscope''' is an essential measurement device when doing analog computing. Nevertheless, even cheap entry level devices cost more than 200 EUR. This page shall document how to use oscilloscopes with [[THAT]] and gives recommendations about devices that are suitable for working with [[The Analog Thing]]. If you don't want to spend money on an oscilloscope, a [[Software Oscilloscope]] maybe an alternative.

== Using Oscilloscopes ==
To watch and measure the values and curves produced during an analog computation or simulation you need additional instruments. The Analog Thing contains a [[voltmeter]] as instrument to setup the coordinates or OP_TIME values. Depending on the [[modes|mode of operation]] in '''REP''' with predefined operation time or '''OP''' with infinite operation this display may be useful for static or slow moving values only.

[[Image:DSO_Yt_display.png|thumb|typical Yt display of signals on a DSO]]
To measure faster events or display signal curves the best tool is an '''oscilloscope'''. For longer operation times (REP, 0.1-10s) a digital storage oscilloscope (DSO) is preferred rather than an analog oscilloscope with a cathode ray tube (CRT). These DSO did get cheaper in the last years but useful DSO's with minimum 2 channels and XY mode are in the price range of about 150-300 € up. XY mode is useful for many applications and allow a better view of complex signals than displaying them just over the time in Yt mode. The typical Lissajous figures for example require the XY mode.

[[Image:DSO_XY_display.png|thumb|typical XY display of the same signals above]]
There are low cost oscilloscope on the market as well in the range of 40-100 € but these come with missing features and have mostly only one channel to display like DSO 138 or missing XY mode like DS 212/213. This is only partly useful with analog computations or simulations and all theses cheap handhelds have only a very small display. Some low cost oscilloscopes come without a display and are connected to a computer as display by software.

== Requirements for Oscilloscopes with The Analog Thing ==
[[File:Hantek IMG 0413.jpg|thumb|A nice entry level DSO: [[Hantek USB DSO]]]]
=== Minimum requirements (cheap devices) ===
* analog oscilloscope with CRT display or software display while connected to computer
* 1 or 2 channels
* XY display mode
* 100 kHz bandwith

Recommendations:
* [[Hantek USB DSO]] (79€ entry price)
* [https://www.meilhaus.de/picoscope-2000.htm Picoscope] (125€ entry price)
* [https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/ Analog Discovery 2] (280€ for academic)
* [https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/adalm2000.html#eb-overview ADMAL2000]

Further cheap alternatives:
* HS101 http://hscope.martinloren.com/HS101-oscilloscope.html
* DroidOscillo https://hackaday.io/project/26360-android-oscilloscope-droidoscillo
* SmartScope https://www.kickstarter.com/projects/751733865/smartscope-reinventing-the-oscilloscope
* FNIRSI 1014D DSO https://www.youtube.com/watch?v=yQKuHJELEOs

=== Medium requirements ===
* 4 channels or separate trigger input
* DSO type (digital storage)

Recommendations:
* [https://www.meilhaus.de/siglent-sds1000x-e.htm Siglent SDS1000X-E] (about 400€)

== Alternatives ==
==== Software 'Scope ====
A cheap alternative for beginners with low budget is to use a [[Software_Oscilloscopes|Software Oscilloscope]]. These solutions rely on your computer for all of the data processing and use a secondary device (such as an Arduino or sound card) for data acquisition.

==== uC-Based "Kit" Oscilloscopes ====
An even cheaper (<20 Euros) alternative, although limited in scope, is one of the microcontroller-based oscilloscopes, either available as a DIY kit or a fully-assembled product. They can be found under the ''DSO138 Oscilloscope'' name on the Internet. They are limited in bandwidth (although plenty enough for the examples in THAT booklet) and single-channel only, with no XY capabilities, but the price is hard to beat.

Here's a link (not affiliated) DSO-138 https://www.reichelt.de/dso-138-oszilloskop-1-kanal-200-khz-12-bit-joy-it-dso-138-p209775.html?&trstct=pol_0&nbc=1

Could be realistically built by someone with some ''Arduino'' knowledge and some spare time as a personal project, maybe by adding XY capabilities.
Good to bring around inside THAT box for patching problems on the go!

==== Old CRT Oscilloscopes ====
If capable of repairing and/or mantaining an old CRT oscillscope, an older model from the 1970's or 1980's may well be worth your time. Even though bandwidth may not surpass the tens of megahertz, it's still quite a lot and usable for all THAT experiments someone may devise. XY mode is almost always a given, but won't have more than two channels.
Price is variable, but can be found for quite less than 100E on usual online platforms.

[[Category:Hardware]]

Diode

2024-12-30T15:18:17Z

Marco-Guerini: +diode picture

[[File:RectifierDiode.jpg|200px|thumb|right|A through-hole rectifier diode]]

A Diode is a two-terminal passive electronic component exhibiting non-linear behaviour. In its ideal form, it allows current in a unidirectional flow, blocking it completely in the other, similarily to a check-valve.

It is used to perform various advanced functions when placed in the feedback path of an [[Open Amplifier]], which are beyond the scope of this introductory page.

While in the heyday of analog computers diode could be implemented as vacuum tubes, on [[The Analog Thing]] silicon diodes are used, of two different kinds: '''Rectifier Diodes''' (Four of them are present on THAT) and '''Zener Diodes''' (There are 2 of these). Further information on Z-diodes can be found [[here]].

The Rectifier Diodes in THAT are {{fill}}

== Physics of Diodes ==

== Diodes in Analog Components ==
Diodes are used in a multitude of different circuits
(Precision Limiter, Bang-Bang, Dead Zone, DFGs)

File:RectifierDiode.jpg

2024-12-30T15:15:36Z

Marco-Guerini: Image of a rectifier diode in THT Package.

== Summary ==
Image of a rectifier diode in THT Package.

Coefficients/Potentiometers

2024-12-30T14:54:06Z

Marco-Guerini: Added an example

'''Coefficients''' are the quantitative parameters of analog computations. [[The Analog Thing]] features eight coefficient potentiometers, allowing the use of up to eight coefficients in an analog program on a single THAT.
Using the potentiometers, each coefficient can be set to any value between <code>0</code> and <code>1</code>. An input to a coefficient potentiometer is multiplied by the value the coefficient potentiometer is set, such that their output is given by <code>output = coefficient * input</code>, with the coefficient being a value between 0 and 1 as said before.

For example a variable A is patched into a potentiometer set to 0.123. The output of the potentiometer would be A*0.123, with the same sign as A. No sign reversal is possible with "normal" potentiometer, though tricks have been developed to allow such a thing.

Several sections of the THAT user interface relate to the use of coefficient potentiometers, as shown in Figure 1:

* The <code>COEFFICIENTS</code> section. This is the area labelled <code>COEFF</code> on your THAT. It contains the input and output sockets for the coefficient potentiometers.
* The <code>COEFFICIENT POTENTIOMETERS</code> section. It contains the eight rotary knobs by which coefficients can be set.
* The <code>MODE SELECTOR</code>.
* The <code>COEFFICIENT SELECTOR</code>. It is used to select the coefficient value to display on the <code>PANEL METER</code> when the <code>MODE SELECTOR</code> is in the <code>COEFF</code> position.
* The <code>PANEL METER</code>.

To familiarize yourself with the use of coefficient potentiometers, follow these steps:

# Set the <code>MODE SELECTOR</code> to position <code>COEFF</code> and set the <code>COEFFICIENT SELECTOR</code> to position <code>1</code>. This connects the output of potentiometer <code>COEFF 1</code> to the <code>PANEL METER</code>.
# Use a patch cable to connect one of the <code>+1</code> sockets in the <code> STABILIZED ±1</code> section to the input (circle) associated with potentiometer <code>COEFF 1</code> in the <code>COEFFICIENTS</code> section (i.e., the uppermost circled socket in the section labelled <code>COEFF</code> on your THAT).
# Change the position of the <code>COEFF 1</code> knob in the <code>COEFFICIENT POTENTIOMETERS</code> section and observe the value displayed on the <code>PANEL METER</code>. The displayed value is available at the output (triangle) associated with potentiometer <code>COEFF 1</code> in the <code>COEFFICIENT</code> section.
# Remove the patch cable plug from the <code>+1</code> socket in the <code> STABILIZED ±1</code> section and plug it into one of the <code>-1</code> sockets in in the <code> STABILIZED ±1</code>.
# Again, change the position of the <code>COEFF 1</code> knob in the potentiometer section and observe the value displayed on the <code>PANEL METER</code>.
# Set the <code>COEFFICIENT SELECTOR</code> to any one of the other potentiometers (say, 4).
# Use a patch cable to connect either of the <code>-1</code> sockets in the <code> STABILIZED ±1</code> with the input (circle) associated with the with the coefficient potentiometer you have chosen using the <code>COEFFICIENT SELECTOR</code> (say, 4).
# Change the position of the coefficient potentiometer knob associated with the coefficient you have chosen using the <code>COEFFICIENT SELECTOR</code> (say, 4) and again observe the value displayed on the <code>PANEL METER</code>.

[[File:THAT_legend_potentiometers_s.png|thumb|left|800px|Figure 1: Parts of the THAT user interface that relate to the familiarization steps described above]]

[[Category:Components of The Analog Thing]]

Capacitor

2024-12-30T14:46:18Z

Marco-Guerini: Added info on Capacitor usage in Analog Computer, WIP

Oscilloscope

2024-12-29T20:18:15Z

Marco-Guerini: /* Alternatives */

An '''Oscilloscope''' is an essential measurement device when doing analog computing. Nevertheless, even cheap entry level devices cost more than 200 EUR. This page shall document how to use oscilloscopes with [[THAT]] and gives recommendations about devices that are suitable for working with [[The Analog Thing]]. If you don't want to spend money on an oscilloscope, a [[Software Oscilloscope]] maybe an alternative.

== Using Oscilloscopes ==
To watch and measure the values and curves produced during an analog computation or simulation you need additional instruments. The Analog Thing contains a [[voltmeter]] as instrument to setup the coordinates or OP_TIME values. Depending on the [[modes|mode of operation]] in '''REP''' with predefined operation time or '''OP''' with infinite operation this display may be useful for static or slow moving values only.

[[Image:DSO_Yt_display.png|thumb|typical Yt display of signals on a DSO]]
To measure faster events or display signal curves the best tool is an '''oscilloscope'''. For longer operation times (REP, 0.1-10s) a digital storage oscilloscope (DSO) is preferred rather than an analog oscilloscope with a cathode ray tube (CRT). These DSO did get cheaper in the last years but useful DSO's with minimum 2 channels and XY mode are in the price range of about 150-300 € up. XY mode is useful for many applications and allow a better view of complex signals than displaying them just over the time in Yt mode. The typical Lissajous figures for example require the XY mode.

[[Image:DSO_XY_display.png|thumb|typical XY display of the same signals above]]
There are low cost oscilloscope on the market as well in the range of 40-100 € but these come with missing features and have mostly only one channel to display like DSO 138 or missing XY mode like DS 212/213. This is only partly useful with analog computations or simulations and all theses cheap handhelds have only a very small display. Some low cost oscilloscopes come without a display and are connected to a computer as display by software.

== Requirements for Oscilloscopes with The Analog Thing ==
[[File:Hantek IMG 0413.jpg|thumb|A nice entry level DSO: [[Hantek USB DSO]]]]
=== Minimum requirements (cheap devices) ===
* analog oscilloscope with CRT display or software display while connected to computer
* 1 or 2 channels
* XY display mode
* 100 kHz bandwith

Recommendations:
* [[Hantek USB DSO]] (79€ entry price)
* [https://www.meilhaus.de/picoscope-2000.htm Picoscope] (125€ entry price)
* [https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/ Analog Discovery 2] (280€ for academic)
* [https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/adalm2000.html#eb-overview ADMAL2000]

Further cheap alternatives:
* HS101 http://hscope.martinloren.com/HS101-oscilloscope.html
* DroidOscillo https://hackaday.io/project/26360-android-oscilloscope-droidoscillo
* DSO-138 https://www.reichelt.de/dso-138-oszilloskop-1-kanal-200-khz-12-bit-joy-it-dso-138-p209775.html?&trstct=pol_0&nbc=1
* SmartScope https://www.kickstarter.com/projects/751733865/smartscope-reinventing-the-oscilloscope
* FNIRSI 1014D DSO https://www.youtube.com/watch?v=yQKuHJELEOs

=== Medium requirements ===
* 4 channels or separate trigger input
* DSO type (digital storage)

Recommendations:
* [https://www.meilhaus.de/siglent-sds1000x-e.htm Siglent SDS1000X-E] (about 400€)

== Alternatives ==
A cheap alternative for beginners with low budget is to use a [[Software_Oscilloscopes|Software Oscilloscope]]. These solutions rely on your computer for all of the data processing and use a secondary device (such as an Arduino or sound card) for data acquisition.

An even cheaper (<20 Euros) alternative, although limited in scope, is one of the microcontroller-based oscilloscopes, either available as a DIY kit or a fully-assembled product. They can be found under the ''DSO138 Oscilloscope'' name on the Internet. They are limited in bandwidth (although plenty enough for the examples in THAT booklet) and single-channel only, with no XY capabilities, but the price is hard to beat.
Could be realistically built by someone with some ''Arduino'' knowledge and some spare time as a personal project, maybe by adding XY capabilities.
Good to bring around inside THAT box for patching problems on the go!

[[Category:Hardware]]

Oscilloscope

2024-12-29T20:17:08Z

Marco-Guerini: Added DSO138 paragraph in the Alternatives section

An '''Oscilloscope''' is an essential measurement device when doing analog computing. Nevertheless, even cheap entry level devices cost more than 200 EUR. This page shall document how to use oscilloscopes with [[THAT]] and gives recommendations about devices that are suitable for working with [[The Analog Thing]]. If you don't want to spend money on an oscilloscope, a [[Software Oscilloscope]] maybe an alternative.

== Using Oscilloscopes ==
To watch and measure the values and curves produced during an analog computation or simulation you need additional instruments. The Analog Thing contains a [[voltmeter]] as instrument to setup the coordinates or OP_TIME values. Depending on the [[modes|mode of operation]] in '''REP''' with predefined operation time or '''OP''' with infinite operation this display may be useful for static or slow moving values only.

[[Image:DSO_Yt_display.png|thumb|typical Yt display of signals on a DSO]]
To measure faster events or display signal curves the best tool is an '''oscilloscope'''. For longer operation times (REP, 0.1-10s) a digital storage oscilloscope (DSO) is preferred rather than an analog oscilloscope with a cathode ray tube (CRT). These DSO did get cheaper in the last years but useful DSO's with minimum 2 channels and XY mode are in the price range of about 150-300 € up. XY mode is useful for many applications and allow a better view of complex signals than displaying them just over the time in Yt mode. The typical Lissajous figures for example require the XY mode.

[[Image:DSO_XY_display.png|thumb|typical XY display of the same signals above]]
There are low cost oscilloscope on the market as well in the range of 40-100 € but these come with missing features and have mostly only one channel to display like DSO 138 or missing XY mode like DS 212/213. This is only partly useful with analog computations or simulations and all theses cheap handhelds have only a very small display. Some low cost oscilloscopes come without a display and are connected to a computer as display by software.

== Requirements for Oscilloscopes with The Analog Thing ==
[[File:Hantek IMG 0413.jpg|thumb|A nice entry level DSO: [[Hantek USB DSO]]]]
=== Minimum requirements (cheap devices) ===
* analog oscilloscope with CRT display or software display while connected to computer
* 1 or 2 channels
* XY display mode
* 100 kHz bandwith

Recommendations:
* [[Hantek USB DSO]] (79€ entry price)
* [https://www.meilhaus.de/picoscope-2000.htm Picoscope] (125€ entry price)
* [https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/ Analog Discovery 2] (280€ for academic)
* [https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/adalm2000.html#eb-overview ADMAL2000]

Further cheap alternatives:
* HS101 http://hscope.martinloren.com/HS101-oscilloscope.html
* DroidOscillo https://hackaday.io/project/26360-android-oscilloscope-droidoscillo
* DSO-138 https://www.reichelt.de/dso-138-oszilloskop-1-kanal-200-khz-12-bit-joy-it-dso-138-p209775.html?&trstct=pol_0&nbc=1
* SmartScope https://www.kickstarter.com/projects/751733865/smartscope-reinventing-the-oscilloscope
* FNIRSI 1014D DSO https://www.youtube.com/watch?v=yQKuHJELEOs

=== Medium requirements ===
* 4 channels or separate trigger input
* DSO type (digital storage)

Recommendations:
* [https://www.meilhaus.de/siglent-sds1000x-e.htm Siglent SDS1000X-E] (about 400€)

== Alternatives ==
A cheap alternative for beginners with low budget is to use a [[Software_Oscilloscopes|Software Oscilloscope]]. These solutions rely on your computer for all of the data processing and use a secondary device (such as an Arduino or sound card) for data acquisition.

An even cheaper alternative, although limited in scope, is one of the microcontroller-based oscilloscopes, either available as a DIY kit or a fully-assembled product. They can be found under the ''DSO138 Oscilloscope'' name on the Internet. They are limited in bandwidth (although plenty enough for the examples in THAT booklet) and single-channel only, with no XY capabilities, but the price is hard to beat.
Could be realistically built by someone with some ''Arduino'' knowledge and some spare time as a personal project, maybe by adding XY capabilities.
Good to bring around inside THAT box for patching problems on the go!

[[Category:Hardware]]

Diode

2024-12-29T20:11:05Z

Marco-Guerini:

A Diode is a two-terminal passive electronic component exhibiting non-linear behaviour. In its ideal form, it allows current in a unidirectional flow, blocking it completely in the other, similarily to a check-valve.

It is used to perform various advanced functions when placed in the feedback path of an [[Open Amplifier]], which are beyond the scope of this introductory page.

While in the heyday of analog computers diode could be implemented as vacuum tubes, on [[The Analog Thing]] silicon diodes are used, of two different kinds: '''Rectifier Diodes''' (Four of them are present on THAT) and '''Zener Diodes''' (There are 2 of these). Further information on Z-diodes can be found [[here]].

The Rectifier Diodes in THAT are {{fill}}

== Physics of Diodes ==

== Diodes in Analog Components ==
Diodes are used in a multitude of different circuits
(Precision Limiter, Bang-Bang, Dead Zone, DFGs)

Open Amplifier

2024-12-29T20:00:41Z

Marco-Guerini: /* Uncommitted Amplifiers in THAT */

An '''Open''' or '''Uncommitted Amplifier''' is an operational amplifier that had its feedback resistor removed, leaving only the input resistor in-circuit.

This allows different feedback elements ([[XIR]] networks, a [[Capacitor]], [[Diode]] and so on) to be connected across the summing junction labeled SJ and the output of the amplifier. Doing this in turn modifies the transfer function of the amplifier, making it potentially more complex and more useful.

== Uncommitted Amplifiers in THAT ==
In THAT, only a [[Summer]] can be converterd to an Open Amplifier. This is accomplished by ground the FB terminal to the ground post directly under it.

This pulls a resistor to ground, activating an [[Analog Switch]] which in turn opens the feedback path between the [[Summing Junction]] and the Output of the amplifier in question.

For Summers 1 to 4, the associated resistors to be pulled to ground are 10k (Version 1.3!) in value, and numbered R46, R49, R52 and R55. The Analog Switches associated are labelled IC29X, with X being a letter A to D, being part of the [[DG212B]]-type IC used throughout THAT.

With feedback removed, the amplifier will immediately overload, lightning the central Overload OL light. To correct this, proper feedback components must be connected between SJ and Out jacks.

== Feedback in Open Amplifiers ==
Proper feedback is achieved by patching a component in place of the original resistor.

Summing Junction

2024-12-29T19:54:35Z

Marco-Guerini: Created page on Summing Junction - To be expanded (Add feedback theory?)

The '''Summing Junction''', labeled SJ, is the node on which the feedback path in an operational amplifier is closed on.

Due to the [[feedback]] action in a properly configured op-amp, the currents at this point are equal and cancel out. This means that the input current through the input resistor and the feedback current through the feedback resistors are equal when the amplifier is working in the linear range, and their algebric sum is zero. Thanks to this, the SJ is also termed a '''Virtual Ground''' point.

Open Amplifier

2024-12-29T19:50:24Z

Marco-Guerini: /* Uncommitted Amplifiers in THAT */

Open Amplifier

2024-12-29T19:48:51Z

Marco-Guerini: Created page on Open Amplifers (Need pictures and links to needed components)

An '''Open''' or '''Uncommitted Amplifier''' is an operational amplifier that had its feedback resistor removed, leaving only the input resistor in-circuit.

This allows different feedback elements ([[XIR]] networks, a [[Capacitor]], [[Diode]] and so on) to be connected across the summing junction labeled SJ and the output of the amplifier. Doing this in turn modifies the transfer function of the amplifier, making it potentially more complex and more useful.

== Uncommitted Amplifiers in THAT ==
In THAT, only a [[Summer]] can be converterd to an Open Amplifier. This is accomplished by ground the FB terminal to the ground post directly under it.

This pulls a resistor to ground, activating an [[Analog Switch]] which in turn opens the feedback path between the Summing Junction and the Output of the amplifier in question.

For Summers 1 to 4, the associated resistors to be pulled to ground are 10k (Version 1.3!) in value, and numbered R46, R49, R52 and R55. The Analog Switches associated are labelled IC29X, with X being a letter A to D, being part of the [[DG212B]]-type IC used throughout THAT.

Diode

2024-12-29T14:52:01Z

Marco-Guerini:

A Diode is a two-terminal passive electronic component exhibiting non-linear behaviour. In its ideal form, it allows current in a unidirectional flow, blocking it completely in the other, similarily to a check-valve.

It is used to perform various advanced functions when placed in the feedback path of an [[Open Amplifier]], which are beyond the scope of this introductory page.

While in the heyday of analog computers diode could be implemented as vacuum tubes, on [[The Analog Thing]] silicon diodes are used, of two different kinds: '''Rectifier Diodes''' (Four of them are present on THAT) and '''Zener Diodes''' (There are 2 of these). Further information on Z-diodes can be found [[here]].

== Physics of Diodes ==

== Diodes in Analog Components ==
Diodes are used in a multitude of different circuits
(Precision Limiter, Bang-Bang, Dead Zone, DFGs)

Diode

2024-12-29T14:45:34Z

Marco-Guerini:

A Diode is a two-terminal passive electronic component exhibiting non-linear behaviour. In its ideal form, it allows current in a unidirectional flow, blocking it completely in the other, similarily to a check-valve.

It is used to perform various advanced functions when placed in the feedback path of an [[Open Amplifier]], which are beyond the scope of this introductory page.

While in the heyday of analog computers diode could be implemented as vacuum tubes, on [[The Analog Thing]] silicon diodes are used, of two different kinds: '''Rectifier Diodes''' (Four of them are present on THAT) and '''Zener Diodes''', of which there are two of them. Further information on Z-diodes can be found [[here]].

== Physics of Diodes ==

== Diodes in Analog Components ==
Diodes are used in a multitude of different circuits
(Precision Limiter, Bang-Bang, Dead Zone, DFGs)

Diode

2024-12-28T19:06:53Z

Marco-Guerini:

Diode

2024-12-28T19:06:29Z

Marco-Guerini: Created page on Diodes, WIP (needs THAT diode code/data)

A Diode is a two-terminal passive electronic component exhibiting non-linear behaviour. In its ideal form, it allows current in a unidirectional flow, blocking it completely in the other, similarily to a check-valve.

It is used to perform various advanced functions when placed in the feedback path of an [[Open Amplifier]], which are beyond the scope of this introductory page.

While in the heyday of analog computers diode could be implemented as vacuum tubes, on [[The Analog Thing]] silicon diodes are used, of two different kinds: '''Rectifier Diodes''' and '''Schottky Diodes'''.

== Rectifier Diodes ==

== Schottky Diodes ==

Capacitor

2024-12-28T18:52:10Z

Marco-Guerini: Created page on Capacitors, work in progress

Modes

2024-12-28T18:35:41Z

Marco-Guerini:

[[File:Modes.png|thumb|An old render of the THAT Mode Switch]]

An Analog Computer is operated by switching it into different '''Modes'''. This allow control of the time-varying computing elements (the integrators) in the computer, which in turn effect the solution of a patched problem.
In [[The Analog Thing]], the modes are chosen by turning an 8-position rotary switch in the lower right of the panel.

The modes of [[The Analog Thing]] are as follows.

== Minion Mode (<code>MINION</code>) ==
In this mode, The Analog Thing is remote-controlled by another The Analog Thing. See [[Daisy Chaining]] for details of how to use this mode. In case you don't have another Analog Thing, this mode is of no interest for you. It doesn't harm to have your Analog Thing in that mode in case nothing is connected, but don't be fooled it would be turned off -- the [[Voltmeter]] is powered off in this mode by intention.


The first position is called MINION and is a remote controlled operation mode where several
ANALOG THING devices can be coupled to a bigger analog computer. See the MINION section
for more details.

== Turned-Off Mode (<code>OFF</code>) ==
In this mode, The Analog Thing is turned off. Please always remove the [[Power]] chord in order to make sure everything is free from electricity if you want to do something crazy with the electronics. Otherwise, it is completely fine to change the program also while the computer is running.


In position OFF the incoming power is switched off electronically with a MOSFET transistor and
power consumption is reduced to about 2 mA / 5 V or approx. 10 mW only. This is a safe
position to connect or disconnect any cables. In any other mode the device is working with a
typical quiescient current of about 300-350 mA / 5 V or 1.5-1.75 W.

== Coefficient-Setting Mode (<code>COEF</code>) ==
This mode is all about fine tuning [[Coefficients/Potentiometers]]. See there for how to use this mode.

The COEFF mode is used to setup the coefficients in a system of differential equations, which
are describing a specific system or task to be simulated with an analog computer. Up to 8
coefficients are available on the ANALOG THING in the single mode or a multiple of 8 using
several ANALOG THING connected together in the MINION mode.

The coefficient 1-8 can be choosen with the coefficient switch and it's current value is shown
on the display and can be changed turning the appropriate potentiometer (single-turn). The
slower and more carefully the turn, the more accurate the value can be setup. Only positive
values from 0.0 – 1.0 are possible. Negative values need an additional inverter or summer. It
is helpful to optimize the system of differential equations to reduce neccessary inversions to a
minimum.

== Initial Conditions Mode (<code>IC</code>) ==
In this mode, the integrators are charged for their [[Initial conditions]]. The yellow <code>IC</code> LED is glowing. This mode is helpful if you manually do a IC/OP cycle.

This is the initial condition of the analog computer. In this position all integrators are cleared
and setup with a initial value. Initial values are setup using an unused coefficient except for an
initial value of 0 which is the default value.

== Operations Mode (<code>OP</code>) ==
In this mode, the analog computer is in ''normal'' operating mode. That means, the integrators are freely integrating. Depending on your application, it can be interesting to have something running for several seconds or even minutes. The green <code>OP</code> LED is glowing. It may occur that you immediately run into some [[Overflow]] problem, in this case the red <code>OL</code> LED glows.

The OP is the functional operation mode. Operation can be halted with switching to next HALT
position and continued switching back to OP. Toggling between OP and HALT allows the user to
measure and investigate the condition of the analog computer inbetween running mode.
Switching back to IC will restart the program from the initial state while HALT will only
interrupt the operation mode without changing conditions of variables.

== Halting Mode (<code>HALT</code>) ==
In this mode, the analog computer is ''pausing'' the integrators. They hold their values and can be readily read off. This is useful for static analysis of the circuit, or for testing values with the Voltmeter. You can go back to Operations Mode at any time.

The HALT mode halts the current operation/program running for investigation of the current
program and variables. Operation can be continued with switching back to OP.

== Repetitive Mode (<code>REP</code>) ==
In this mode, the analog computer is automatically and repeatedly switching between IC and OP mode. While the IC time is hard coded to {{fill}}, the OP time can be chosen within a range of minimum {{fill}} and maximum {{fill}} miliseconds with the slider called <code>OP TIME</code>.


The schematics below shows the realisation of the repeated operation which is a feature to
visualize the signals in an Y/T oscilloscope view. There are 2 options available for long
operation times (slow mode) from less than 100ms to 10 seconds and a faster mode REPF for
operation times of less than 1ms to 100ms.

== Fast Repetitive Mode (<code>REPF</code>) ==
REPF is the mode for faster operation and allows the setup in the range of 1ms to 100ms. In
the REPF mode the IC time (initial setup) is reduced to about 1.5ms. This is realized with the
analog switches in the time control schematics. The pictures below show the operation times of
10ms and 1ms.

[[Category:Components of The Analog Thing]]

Modes

2024-12-28T18:34:12Z

Marco-Guerini:

[[File:Modes.png|thumb|The mode switch]]

An Analog Computer is operated by switching its state into different '''Modes'''. This allow control of the time-varying elements (the integrators) in the computer, which in turn effect the solution of a patched problem.
In [[The Analog Thing]], the modes are chosen by turning an 8-position rotary switch in the lower right of the front panel.

The modes of [[The Analog Thing]] are as follows.

== Minion Mode (<code>MINION</code>) ==
In this mode, The Analog Thing is remote-controlled by another The Analog Thing. See [[Daisy Chaining]] for details of how to use this mode. In case you don't have another Analog Thing, this mode is of no interest for you. It doesn't harm to have your Analog Thing in that mode in case nothing is connected, but don't be fooled it would be turned off -- the [[Voltmeter]] is powered off in this mode by intention.


The first position is called MINION and is a remote controlled operation mode where several
ANALOG THING devices can be coupled to a bigger analog computer. See the MINION section
for more details.

== Turned-Off Mode (<code>OFF</code>) ==
In this mode, The Analog Thing is turned off. Please always remove the [[Power]] chord in order to make sure everything is free from electricity if you want to do something crazy with the electronics. Otherwise, it is completely fine to change the program also while the computer is running.


In position OFF the incoming power is switched off electronically with a MOSFET transistor and
power consumption is reduced to about 2 mA / 5 V or approx. 10 mW only. This is a safe
position to connect or disconnect any cables. In any other mode the device is working with a
typical quiescient current of about 300-350 mA / 5 V or 1.5-1.75 W.

== Coefficient-Setting Mode (<code>COEF</code>) ==
This mode is all about fine tuning [[Coefficients/Potentiometers]]. See there for how to use this mode.

The COEFF mode is used to setup the coefficients in a system of differential equations, which
are describing a specific system or task to be simulated with an analog computer. Up to 8
coefficients are available on the ANALOG THING in the single mode or a multiple of 8 using
several ANALOG THING connected together in the MINION mode.

The coefficient 1-8 can be choosen with the coefficient switch and it's current value is shown
on the display and can be changed turning the appropriate potentiometer (single-turn). The
slower and more carefully the turn, the more accurate the value can be setup. Only positive
values from 0.0 – 1.0 are possible. Negative values need an additional inverter or summer. It
is helpful to optimize the system of differential equations to reduce neccessary inversions to a
minimum.

== Initial Conditions Mode (<code>IC</code>) ==
In this mode, the integrators are charged for their [[Initial conditions]]. The yellow <code>IC</code> LED is glowing. This mode is helpful if you manually do a IC/OP cycle.

This is the initial condition of the analog computer. In this position all integrators are cleared
and setup with a initial value. Initial values are setup using an unused coefficient except for an
initial value of 0 which is the default value.

== Operations Mode (<code>OP</code>) ==
In this mode, the analog computer is in ''normal'' operating mode. That means, the integrators are freely integrating. Depending on your application, it can be interesting to have something running for several seconds or even minutes. The green <code>OP</code> LED is glowing. It may occur that you immediately run into some [[Overflow]] problem, in this case the red <code>OL</code> LED glows.

The OP is the functional operation mode. Operation can be halted with switching to next HALT
position and continued switching back to OP. Toggling between OP and HALT allows the user to
measure and investigate the condition of the analog computer inbetween running mode.
Switching back to IC will restart the program from the initial state while HALT will only
interrupt the operation mode without changing conditions of variables.

== Halting Mode (<code>HALT</code>) ==
In this mode, the analog computer is ''pausing'' the integrators. They hold their values and can be readily read off. This is useful for static analysis of the circuit, or for testing values with the Voltmeter. You can go back to Operations Mode at any time.

The HALT mode halts the current operation/program running for investigation of the current
program and variables. Operation can be continued with switching back to OP.

== Repetitive Mode (<code>REP</code>) ==
In this mode, the analog computer is automatically and repeatedly switching between IC and OP mode. While the IC time is hard coded to {{fill}}, the OP time can be chosen within a range of minimum {{fill}} and maximum {{fill}} miliseconds with the slider called <code>OP TIME</code>.


The schematics below shows the realisation of the repeated operation which is a feature to
visualize the signals in an Y/T oscilloscope view. There are 2 options available for long
operation times (slow mode) from less than 100ms to 10 seconds and a faster mode REPF for
operation times of less than 1ms to 100ms.

== Fast Repetitive Mode (<code>REPF</code>) ==
REPF is the mode for faster operation and allows the setup in the range of 1ms to 100ms. In
the REPF mode the IC time (initial setup) is reduced to about 1.5ms. This is realized with the
analog switches in the time control schematics. The pictures below show the operation times of
10ms and 1ms.

[[Category:Components of The Analog Thing]]