Circuit Fantasia

How to Understand, Present and Invent Electronic Circuits

https://web.archive.org/web/20251118142906/https://www.circuit-fantasia.com/index_pay.html

 (I have used plain text URLs for archived materials to ensure the links remain functional and reliable for future reference)

I started this interactive site in 2002. I created most of pages by means of Macromedia Flash (now Adobe).

Unfortunately, in 2021, Adobe stopped Flash Player. However, there was still a way to watch Flash movies - Ruffle Flash emulator.

At the end of 2025, I closed the site after archiving and uploading it to the Internet Archive. This is the homepage created with Flash. Since not all links in it work, you can use the list of plain-text links below to navigate between the pages.

Here are the links of the home page accompanied with a brief description.

Philosophy

Creation https://web.archive.org/web/20251022123607/https://www.circuit-fantasia.com/philosophy/introduction.html shows how I created my philosophy

Examples of inventing https://web.archive.org/web/20251016123334/https://www.circuit-fantasia.com/philosophy/examples-of-inventing.html tells how I revealed the secret of op-amp inverting circuits in four steps

My creative evolution https://web.archive.org/web/20070926212223/http://www.circuit-fantasia.com/philosophy/my-creative-evolution.html) is an initial version of my bio (see the present full version)

Penetrations https://web.archive.org/web/20080509090735/http://www.circuit-fantasia.com/philosophy/my-great-penetrations.html shows my great circuit insights

Papers https://web.archive.org/web/20070903150930/http://www.circuit-fantasia.com/philosophy/list_of_papers.htm is a list of my materials published until 2000

Circuit Stories on the Whiteboard https://web.archive.org/web/20251016173724/https://www.circuit-fantasia.com/circuit_stories/combined_list_of_circuits.htm

Understanding https://web.archive.org/web/20250811233745/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/understanding_list_of_circuits.htm

What is the idea behind a constant current source? https://web.archive.org/web/20240520122214/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/current_source_philosophy.htm

Simple current source shortened https://web.archive.org/web/20251102103757/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/simple_current_source/simple_current_source.htm and real loaded https://web.archive.org/web/20080123082841/http://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/simple_current_source_real/simple_current_source_real.htm

Simple BJT current source https://web.archive.org/web/20251102104308/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/simple_bjt_current_source/simple_bjt_current_source.htm

Transistor current source with shifting diode https://web.archive.org/web/20251102134352/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/transistor_source_diode/transistor_source_diode.htm

Widlar op-amp current source https://web.archive.org/web/20251102135408/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/widlar_op-amp_current_source/widlar_op-amp_current_source.htm

Inverting op-amp current source https://web.archive.org/web/20251102134035/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/inv_op-amp_current_source/inv_op-amp_current_source.htm

Howland op-amp current source https://web.archive.org/web/20251103053705/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/current_source/howland_current_source/howland_current_source.htm

Negative impedance converter NIC https://web.archive.org/web/20251102141459/https://www.circuit-fantasia.com/circuit_stories/understanding_circuits/nic/vnic/vnic.htm

Building https://web.archive.org/web/20241013041926/https://www.circuit-fantasia.com/circuit_stories/building_circuits/building_list_of_circuits.htm

Op-amp ammeter https://web.archive.org/web/20251101202916/https://www.circuit-fantasia.com/circuit_stories/building_circuits/ammeter/op-amp_ammeter/op-amp_ammeter.htm

Op-amp RC integrator full - https://web.archive.org/web/20251101202140/https://www.circuit-fantasia.com/circuit_stories/building_circuits/integrator/op-amp_rc_integrator.htm, roll - https://web.archive.org/web/20251102075455/https://www.circuit-fantasia.com/circuit_stories/building_circuits/integrator/op-amp_rc_integrator_roll.htm, short - https://web.archive.org/web/20251102075455/https://www.circuit-fantasia.com/circuit_stories/building_circuits/integrator/op-amp_rc_integrator_short.htm

How do we build a constant current source? https://web.archive.org/web/20251102103651/https://www.circuit-fantasia.com/circuit_stories/building_circuits/current_source/current_source_philosophy/current_source_philosophy.htm

Inventing https://web.archive.org/web/20240520112211/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/inventing_list_of_circuits.htm

Passive voltage-to-current converter https://web.archive.org/web/20251101202109/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/v-to-i_converter/v-to-i_converter.htm

Passive current-to-voltage converter https://web.archive.org/web/20251101202742/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/i-to-v_converter/i-to-v_converter.htm

Op-amp inverting voltage-to-current converter https://web.archive.org/web/20251101203315/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/active_v-to-i_converter/active_v-to-i_converter.htm

Op-amp inverting current-to-voltage converter https://web.archive.org/web/20251101203723/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/active_i-to-v_converter/active_i-to-v_converter.htm

Transimpedance amplifier https://web.archive.org/web/20251101202155/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/transimpedance_amplifier/transimpedance_amplifier.htm

How do we create a virtual ground? https://web.archive.org/web/20251102075907/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/virtual_ground/virtual_ground.htm

How do we invent constant current source? https://web.archive.org/web/20251016173617/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/current_source/current_source_philosophy/current_source_philosophy.htm

Current biased bridge https://web.archive.org/web/20251102111030/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/current_biased_bridge/current_biased_bridge.htm

How do We Create Dynamic Resistance? https://web.archive.org/web/20251102105400/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/dynamic_resistance/dynamic_resistance.htm

How do We Make Decreased, Zero and Negative Differential Resistance? https://web.archive.org/web/20251102105640/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/r_decreased_resistance/r_decreased_resistance.htm

How to Compensate Resistive Losses by Series Connected Negative Resistor https://web.archive.org/web/20251102111306/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/ser_nr_comp/ser_neg_res_comp.htm

How to Compensate Resistive Losses by Parallel Connected Negative Resistor https://web.archive.org/web/20251102111306/https://www.circuit-fantasia.com/circuit_stories/inventing_circuits/par_nr_comp/par_neg_res_comp.htm

        

Tutorials Flash

Build to understand circuits (uncompleted)

Introduction https://web.archive.org/web/20251017090142/https://www.circuit-fantasia.com/tutorial/intro/welcome-pay.html reveals the philosophy of this novel approach in electronics education

Table of contents https://web.archive.org/web/20251021153120/https://www.circuit-fantasia.com/tutorial/content/table-of-contents.html Part 1. In the kingdom of electricity (passive circuits)

Unit 1-1 Voltage causes current https://web.archive.org/web/20251021152243/https://www.circuit-fantasia.com/tutorial/unit1/unit1-pay.html introduces the first most elementary building blocks

Op-amp interactive builder https://web.archive.org/web/20251017085547/https://www.circuit-fantasia.com/collections/tools/pnfb-builder.html "builds" over 40 op-amp inverting circuits with negative feedback

Strange Things can be Put in the Feedback Loop, after Tom Hayes's Student Manual https://web.archive.org/web/20251021180859/https://www.circuit-fantasia.com/collections/tools/strange-things.html builds over a dozen op-amp circuits with a disturbance put into the feedback loop

        

Collections

List of circuits https://web.archive.org/web/20251103081133/https://www.circuit-fantasia.com/tutorial/intro/list_of_circuits.htm

Circuit library https://web.archive.org/web/20181111030127/http://www.circuit-fantasia.com/my-students/ske2004/intro/library.htm

V-to-I converter builds a passive voltage-to-current converter

https://web.archive.org/web/20251016150946/https://www.circuit-fantasia.com/collections/circuit-collection/circuits/old-circuits/v-to-i-old.html

         

I-to-V converter creates an opposite current-to-voltage converter

https://web.archive.org/web/20251017071320/https://www.circuit-fantasia.com/collections/circuit-collection/circuits/old-circuits/i-to-v-old.html

Passive summer builds a compound passive resistive summer

https://web.archive.org/web/20251017073750/https://www.circuit-fantasia.com/collections/circuit-collection/circuits/old-circuits/v-to-v-sum-old.html

Active summer transmutes a passive summer into an active one

https://web.archive.org/web/20251017074314/https://www.circuit-fantasia.com/collections/circuit-collection/circuits/old-circuits/v-to-v-active-sum-old.html

Circuit Questions & Answers

Great questions https://web.archive.org/web/20251103085521/https://www.circuit-fantasia.com/e-answers/great-answers-home.html contains general questions about circuits

All questions https://web.archive.org/web/20251103132128/https://www.circuit-fantasia.com/e-answers/all-answers-home.html contains "ordinary" questions about circuits

Week's questions https://web.archive.org/web/20251103132905/https://www.circuit-fantasia.com/tutorial/intro/list_of_questions.htm

Paradoxes of circuits is another part of the site started in September 2003 where I show the great paradoxes and absurds in electronic circuits

List of paradoxes https://web.archive.org/web/20251102191623/https://www.circuit-fantasia.com/e-paradoxes/list_of_paradoxes.htm

Contradictions

List of contradictions https://web.archive.org/web/20251022122414/https://www.circuit-fantasia.com/tutorial/intro/list_of_contradictions_all.htm

Circuit Conflicts

List of conflicts https://web.archive.org/web/20251103132929/https://www.circuit-fantasia.com/tutorial/intro/list_of_conflicts.htm

Principles

List of principles https://web.archive.org/web/20251021153723/https://www.circuit-fantasia.com/tutorial/intro/list_of_principles.htm

Building schemes

List of schemes https://web.archive.org/web/20251022123142/https://www.circuit-fantasia.com/tutorial/intro/list_of_building_schemes_all.htm

My students (2004)

My teacher's story https://web.archive.org/web/20251022143304/https://www.circuit-fantasia.com/my_work/conferences/et_2004/course_paper.htm

Classes on Analog and mixed electronics 2004 https://web.archive.org/web/20251016164913/https://www.circuit-fantasia.com/my-students/ske2004/intro/intro-ske.htm

Elementary Passive Converters with Current Output https://web.archive.org/web/20251016165004/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-1.htm

Elementary Passive Converters with Voltage Output https://web.archive.org/web/20251016165008/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-2.htm

Compound Passive Converters with Voltage Output https://web.archive.org/web/20251016164953/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-3.htm

Passive Integrators and Differentiators https://web.archive.org/web/20251016165210/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-4.htm

Diode Circuits https://web.archive.org/web/20251016164931/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-5.htm

Transistor Circuits without Feedback https://web.archive.org/web/20251016165014/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-6.htm

Transistor Circuits with Feedback https://web.archive.org/web/20251016165000/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-7.htm

Op-amp Amplifiers with Negative Feedback https://web.archive.org/web/20251016165145/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-8.htm

Op-amp Converters with Parallel Negative Feedback https://web.archive.org/web/20251016165154/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-9.htm

Op-amp Circuits with Positive Feedback https://web.archive.org/web/20251016165014/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-10.htm

Components and Sub-systems for Analog-Digital Signal Processing https://web.archive.org/web/20251016164941/https://www.circuit-fantasia.com/my-students/ske2004/classes/current-ske-11.htm

Fedback from readers https://web.archive.org/web/20251103075814/https://www.circuit-fantasia.com/my-students/ske2004/intro/feedback-ske.htm