Good demonstration of how the current flow through a diode affects the resistance of a forward biased junction. The equivalent resistance will be approximately 26 divided by the current in milliamps. Remember that the AC amplitude will affect the current through the circuit and therefore the resistance, possibly leading to distortion of the waveform. This effect is commonly used as an amplitude control in many devices, usually by acting as a variable shunt. The more diodes in series the greater the signal voltage swing capability before distortion becomes too bad.
Very clear example of how a sine wave can pass through the diode but I'm not sure the purpose of the diode in the audio circuit ? why not simply use a resistor and coupling capacitor ?
Interesting Video! So could You also make a Silicon Diode more "sensitive" (make it produce less Distortion at a lower Voltage) with DC-Biasing the Diode?
I imagine people who thought it would distort were thinking about "diode clippers" that go from signal to ground like you would have in a guitar fuzz, etc.
It's not across the diode, it's through the diode. When the diode is not biased it rectifies the audio signal. When the diode is forward biased it turns into a wire and the audio signal passes through the diode undistorted.
@@AllAmericanFiveRadio Thanks for your reply. I used "across" to denote a voltage as opposed to a current ("through"). Forgive my possible misconceptions ... but I understand that when a "diode is forward biased it turns into a wire" but only for current in the direction of the arrowhead on the diode schematic symbol. In your measurement circuit, the audio signal current is going in the direction opposite direction. Is my problem that you are talking only about the diode(s) in 1) the measurement circuit used and 2) the amplifier circuit shown but we are NOT referring to the operation of diodes in general?
