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* In printed electronics, we use capacitors to detect the presence of fingers by a change in capacitance | * In printed electronics, we use capacitors to detect the presence of fingers by a change in capacitance | ||
[http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0Av+-112+16+-112+-64+0+2+400+5+0+0+0.5%0Ax+-208+68+-1+71+4+12+Fast%5Cssignals%5Cspass%5Csthrough%5Cscapacitors!%0Ax+-206+-135+-34+-132+4+20+Capacitive%5CsSensors%0Aw+-112+16+32+16+0%0Ar+32+16+32+-64+0+1000%0Ac+-112+-64+32+-64+0+1e-9+-5%0Ax+-211+145+340+148+4+12+When%5Cswe%5Csapproach%5Csthis%5Csplate%5Cswith%5Csour%5Csfingers,%5Csit%5Csforms%5Csa%5Cssecond%5Csplate%5Csand%5Csincreases%5Csthe%5Cscapacitance,%0Ax+-209+93+213+96+4+12+The%5Csamplitude%5Csof%5Csthe%5Cssignal%5Csthat%5Cspasses,%5Csdepends%5Cson%5Csthe%5Cssize%5Csof%5Csthe%5Cscapacitor.%0Ax+-209+116+141+119+4+12+With%5Cscapacitove%5Cssensors,%5Cswe%5Csprint%5Csonly%5Csone%5Csplate%5Csof%5Csthe%5Cscapacitor.%0Ax+-208+171+95+174+4+12+which%5Csin%5Csturns%5Csamplifies%5Csthe%5Cssignal%5Csthat%5Cspasses%5Csthrough.%0Ax+-208+197+71+200+4+12+We%5Cscan%5Csmeasure%5Csthis%5Cssignal%5Cswith%5Csa%5Csmicro%5Cscontroller!%0Ao+0+8+0+4098+5+0.1+0+2+0+3%0Ao+4+8+0+4098+5+0.1+1+2+4+3%0A Capacitive Sensors] | [http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0Av+-112+16+-112+-64+0+2+400+5+0+0+0.5%0Ax+-208+68+-1+71+4+12+Fast%5Cssignals%5Cspass%5Csthrough%5Cscapacitors!%0Ax+-206+-135+-34+-132+4+20+Capacitive%5CsSensors%0Aw+-112+16+32+16+0%0Ar+32+16+32+-64+0+1000%0Ac+-112+-64+32+-64+0+1e-9+-5%0Ax+-211+145+340+148+4+12+When%5Cswe%5Csapproach%5Csthis%5Csplate%5Cswith%5Csour%5Csfingers,%5Csit%5Csforms%5Csa%5Cssecond%5Csplate%5Csand%5Csincreases%5Csthe%5Cscapacitance,%0Ax+-209+93+213+96+4+12+The%5Csamplitude%5Csof%5Csthe%5Cssignal%5Csthat%5Cspasses,%5Csdepends%5Cson%5Csthe%5Cssize%5Csof%5Csthe%5Cscapacitor.%0Ax+-209+116+141+119+4+12+With%5Cscapacitove%5Cssensors,%5Cswe%5Csprint%5Csonly%5Csone%5Csplate%5Csof%5Csthe%5Cscapacitor.%0Ax+-208+171+95+174+4+12+which%5Csin%5Csturns%5Csamplifies%5Csthe%5Cssignal%5Csthat%5Cspasses%5Csthrough.%0Ax+-208+197+71+200+4+12+We%5Cscan%5Csmeasure%5Csthis%5Cssignal%5Cswith%5Csa%5Csmicro%5Cscontroller!%0Ao+0+8+0+4098+5+0.1+0+2+0+3%0Ao+4+8+0+4098+5+0.1+1+2+4+3%0A Capacitive Sensors] | ||
* Here is a circuit for driving an LED: | |||
[http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0Ar+-240+-48+-144+-48+0+100%0Av+-240+32+-240+-48+0+0+40+5+0+0+0.5%0A370+-64+-48+-64+32+1+0%0Ax+-315+101+405+104+4+12+For%5Csdriving%5Csan%5CsLED%5Cswithout%5Csdestroying%5Csit,%5Csyou%5Csneed%5Csto%5Csadd%5Csa%5Csseries%5Csreistor%5Cs(R).%5CsTo%5Cscalculate%5Csthe%5Cscorrect%5Csresistance,%5Csuse%5Csthe%5Csformula%5Csabove!%0Ax+41+-55+160+-52+4+18+R%5Cs%5Cq%5Cs(Vs%5Cs-%5CsVf)%5Cs/%5CsI%0Aw+-240+32+-240+48+0%0Aw+-240+48+-64+48+0%0Aw+-64+48+-64+32+0%0Ap+-304+-48+-304+48+1+0%0Aw+-304+48+-240+48+0%0Aw+-304+-48+-240+-48+0%0Ax+-88+-159+33+-156+4+18+Driving%5Csan%5CsLED%0Ad+-144+-48+-64+-48+2+old-default-led%0Ap+-144+-96+-64+-96+1+0%0Aw+-144+-96+-144+-48+0%0Aw+-64+-96+-64+-48+0%0Aw+-240+-48+-240+-96+0%0Ap+-240+-96+-144+-96+1+0%0Ax+43+-23+185+-20+4+12+Vs%5Cs...%5Csvoltage%5Csof%5Csthe%5Cssource%0Ax+44+6+332+9+4+12+Vf%5Cs...%5Csforward%5Csvoltage%5Csdrop%5Csof%5Csthe%5CsLED%5Cs(from%5Csdatasheet)%0Ax+45+32+434+35+4+12+I...%5Csdesired%5Cscurrent%5Csthrough%5CsLED%5Cs(below%5Csmaximum%5Cscurrent%5Csfrom%5Csdatasheet)%0Ao+2+64+0+4099+0.0000762939453125+0.1+0+2+2+3%0A LED circuit] | |||
Latest revision as of 14:01, 15 October 2019
Here you find learning material in the form of circuit simulations, that lead you to the understanding of amplifiers and other signal conditioning circuits that we use throughout the course. Feel free to experiment with them, they are editable and saved via the encoded URL. You cannot destroy them and it is easy to share edited versions. Here is an introduction to the circuit simulator.
- The foundation of understanding electric circuits is Ohm's law.
- We can calculate series and parallel resistances with Ohm's law:
series and parallel resistances
- A very powerful concept is the voltage divider, it allows us to attenuate (but not amplify!) any voltage in any circuit
voltage divider with even resistors
- The capacitor is an inportant building block, which can store charge over a given amount of time.
- In printed electronics, we use capacitors to detect the presence of fingers by a change in capacitance
- Here is a circuit for driving an LED: