721
edits
(3 intermediate revisions by the same user not shown) | |||
Line 35: | Line 35: | ||
[[file: square_wave_oscillator.png]] This is the breadboard version of the square wave oscillator. The output frequency should be around 50-100Hz. You can connect this to a small speaker or headphone directly. To connect it to a Hifi amplifier input, you need to convert the output voltage from around +-4V to +-1V by using a voltage divider, as shown in the second version with the potentiometer. | [[file: square_wave_oscillator.png]] This is the breadboard version of the square wave oscillator. The output frequency should be around 50-100Hz. You can connect this to a small speaker or headphone directly. To connect it to a Hifi amplifier input, you need to convert the output voltage from around +-4V to +-1V by using a voltage divider, as shown in the second version with the potentiometer. In this circuit I use the 4-band resistor color marking. | ||
[[file: square_wave_oscillator_potentiometer.png]] This is the breadboard version of the square wave oscillator with potentiometer and output to | [[file: square_wave_oscillator_potentiometer.png]] This is the breadboard version of the square wave oscillator with potentiometer and output to +-1V (suitable for a hifi input (aux)). The output frequency varies with the potentometer. In this circuit you will find the 5-band resistor color marking. Beware: the output voltage divider before the cinch (RCA) connector is a 10kOhm and a 2kOhm resistor. Anything approximate in a 5:1 Ratio should do the trick and attenuate the output voltage below +-1V. | ||
== Filters == | == Filters == | ||
Line 48: | Line 48: | ||
[http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+12.050203812241895+54+5+43%0Ag+-256+32+-256+48+0%0Ax+-164+-202+66+-199+4+18+Simple%5CsActive%5CsLowpass%5CsFilter%0Aw+-256+-32+-224+-32+0%0A207+-112+-48+-64+-48+4+output%0Ac+-256+-32+-256+32+0+1.0000000000000001e-7+0.41109475569201465%0Ar+-256+-32+-352+-32+0+1000%0AR+-352+-32+-400+-32+0+1+1591.5+1+0+0+0.5%0Ax+-13+-92+91+-89+4+14+f%5Cs%5Cq%5Cs1%5Cs/%5Cs(2*pi*R*C)%0Ax+-14+-67+180+-64+4+14+f%5Cs%5Cq%5Cs1%5Cs/%5Cs(2*pi*10%5E3%5CsOhm*10%5E-7%5CsF)%0Ax+-14+-40+156+-37+4+14+f%5Cs%5Cq%5Cs10%5E4%5Cs/%5Cs(2*pi)%5Cq10000/%5Cs2pi%0Ax+-14+-12+69+-9+4+14+f%5Cs%5Cq%5Cs1591,5%5CsHz%0Ax+-13+-130+293+-127+4+14+Calculation%5Csof%5Csfilter%5Cscutoff%5Cspoint%5Cs(-3dB%5CsFrequency)%0Aw+-224+-112+-224+-64+0%0Aw+-112+-112+-224+-112+0%0Aw+-112+-48+-112+-112+0%0Aa+-224+-48+-112+-48+8+15+-15+1000000+0.4110906447855668+0.41109475569201465+100000%0Ao+3+4+0+4106+1.25+0.00009765625+0+2+3+3%0A Simple Active Lowpass Filter] | [http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+12.050203812241895+54+5+43%0Ag+-256+32+-256+48+0%0Ax+-164+-202+66+-199+4+18+Simple%5CsActive%5CsLowpass%5CsFilter%0Aw+-256+-32+-224+-32+0%0A207+-112+-48+-64+-48+4+output%0Ac+-256+-32+-256+32+0+1.0000000000000001e-7+0.41109475569201465%0Ar+-256+-32+-352+-32+0+1000%0AR+-352+-32+-400+-32+0+1+1591.5+1+0+0+0.5%0Ax+-13+-92+91+-89+4+14+f%5Cs%5Cq%5Cs1%5Cs/%5Cs(2*pi*R*C)%0Ax+-14+-67+180+-64+4+14+f%5Cs%5Cq%5Cs1%5Cs/%5Cs(2*pi*10%5E3%5CsOhm*10%5E-7%5CsF)%0Ax+-14+-40+156+-37+4+14+f%5Cs%5Cq%5Cs10%5E4%5Cs/%5Cs(2*pi)%5Cq10000/%5Cs2pi%0Ax+-14+-12+69+-9+4+14+f%5Cs%5Cq%5Cs1591,5%5CsHz%0Ax+-13+-130+293+-127+4+14+Calculation%5Csof%5Csfilter%5Cscutoff%5Cspoint%5Cs(-3dB%5CsFrequency)%0Aw+-224+-112+-224+-64+0%0Aw+-112+-112+-224+-112+0%0Aw+-112+-48+-112+-112+0%0Aa+-224+-48+-112+-48+8+15+-15+1000000+0.4110906447855668+0.41109475569201465+100000%0Ao+3+4+0+4106+1.25+0.00009765625+0+2+3+3%0A Simple Active Lowpass Filter] | ||
* We can use this simple topologie to connect it to our breadboarded oscillator as you can see on the following fritzing breadboard drawing: | |||
[[file:oscillator_potentiometer_filter.png]] | |||
* Still, since the resistance of our source adds to our first resistor, the cutoff point will change, when the resistance of the source changes. To mitigate this we can change the topologie of our filter like so: | * Still, since the resistance of our source adds to our first resistor, the cutoff point will change, when the resistance of the source changes. To mitigate this we can change the topologie of our filter like so: |