IFD:Printing Acoustic Interfaces/acoustic sensing circuits: Difference between revisions

← Older edit

IFD:Printing Acoustic Interfaces/acoustic sensing circuits (view source)

Revision as of 20:03, 27 June 2019

920 bytes added , 27 June 2019

no edit summary

Clemensw

Bureaucrats, Administrators

721

edits

@@ Line 9: / Line 9: @@
 The sending circuit is a very simple triangle wave generator using parasitic effects of the circuit board to reach high frequencies and at the same time provide minimal component counts. The output of the sending circuit is putting and removing charge to one plate of the printed capacitor in the shape of a high frequency triangle wave.
 [[File:receiving_circuit.png| thumb| left| receiving circuit]]
+The receiving capacitor plate's capacity is modulated by the high frequency triangle wave from the first plate, as well as the distance from this first plate. The distance modulation in audio range (0-20kHz) is what we are interested in detecting. First we pre-amplify the modulated signal from the receiving capacitor plate with a charge mode amplifier, than we detect the envelope of the high frequency wave with a half wave rectifier and a low pass filter and finally amplify and buffer the resulting envelope. The output of this receiver circuit corresponds to the distance of the two capacitor plates in audio rate, the signal we were originally interested to detect.
+The following two diagrams show the breadboarded sending and receiving circuits using two TL072's or one TL074. Note that instead of four AA batteries we are using two 9V blocks two get a dual power supply of +-9V.
 [[File:microphone_amp_tl072_Steckplatine.png | thumb|left| TL072 Version ]]
 [[File:microphone_amp_tl074_Steckplatine.png | thumb|left| TL074 Version ]]
+==Falstad Circuit Simulations==
 [http://www.falstad.com/circuit/circuitjs.html?cct=$+1+1.0416666666666667e-7+5.459815003314424+50+5+43%0Ag+-384+32+-384+48+0%0Av+-560+-48+-480+-48+0+6+300000+1+0+0+0.5%0Ax+-218+-233+-5+-230+4+24+Receiver%5Cs@%5Cs309kHz%0Aa+-384+16+-272+16+8+15+-15+1000000+-0.000004640178701983729+0+100000%0A207+336+-64+384+-64+4+output%0Aw+-272+16+-272+-48+0%0Aw+-384+-48+-384+0+0%0Ar+-368+-48+-288+-48+0+100000%0Aw+-368+-48+-384+-48+0%0Aw+-288+-48+-272+-48+0%0Ag+-560+-48+-560+-16+0%0Ac+-384+-48+-480+-48+0+1e-11+0.6583435098491084%0Ac+-384+-96+-272+-96+0+1e-11+-0.4640225103770748%0Aw+-384+-96+-384+-48+0%0Aw+-272+-96+-272+-48+0%0Aw+320+-128+336+-128+0%0Aw+240+-128+224+-128+0%0Ar+240+-128+320+-128+0+100000%0Aw+224+-128+224+-80+0%0Aw+336+-64+336+-128+0%0Aa+224+-64+336+-64+8+15+-15+1000000+0.06877102612285581+0.06877859093572933+100000%0Ar+144+-128+224+-128+0+10000%0Al+-176+-48+-176+16+0+0.00033+-0.00003235853297545487%0Ag+-176+16+-176+48+0%0Ac+-112+-48+-112+16+0+3.3e-10+-0.08826364906288835%0Aw+-176+-48+-112+-48+0%0Ad+-48+-48+48+-48+2+default%0Ac+48+-48+48+16+0+1e-9+0.06877929646277242%0Ar+112+-48+112+16+0+100000%0Ag+48+16+48+48+0%0Aw+48+16+112+16+0%0Aw+48+-48+112+-48+0%0Ac+112+-48+224+-48+0+1e-7+7.055270430933458e-7%0Ag+144+-128+144+-112+0%0Ar+-272+-48+-176+-48+0+1000%0Ac+-48+-48+-48+16+0+4.7e-10+-0.08826364906288835%0Aw+-112+-48+-48+-48+0%0Ag+-112+16+-112+48+0%0Ag+-48+16+-48+48+0%0Ab+-459+-176+-262+99+0%0Ab+-247+-176+-28+98+0%0Ab+-16+-177+130+98+0%0Ab+139+-177+349+97+0%0Ab+-482+-175+-594+99+0%0Ax+-566+-142+-518+-139+4+12+mic%5Csinput%0Ax+-423+-145+-283+-142+4+12+charge%5Csmode%5Cspre-amplifier%0Ax+-203+-145+-78+-142+4+12+309%5CskHz%5Csbandpass%5Csfilter%0Ax+3+-144+99+-141+4+12+half%5Cswave%5Csrectifier%5Cs%0Ax+3+-123+99+-120+4+12+and%5Cslow%5Cspass%5Csfilter%0Ax+200+21+282+24+4+12+output%5Csamplifier%0Ao+1+64+0+4098+1.25+0.1+0+2+1+3%0Ao+4+64+0+4099+2.5+0.00009765625+1+2+4+3%0Ao+25+4+0+5122+0.625+0.1+2+2+25+3%0A Receiving Circuit]