Timeline for Amplification before tubes and transistors were invented
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 7, 2017 at 9:09 | comment | added | hobbs | Estimating the flow rate (the m^3/s term) seems like the hard part, but maybe it's fair to use the speed of sound times the effective aperture area of the mouthpiece, times a term to convert peak to RMS :) | |
| Oct 7, 2017 at 9:04 | comment | added | hobbs | @andre the common unit is power. 1 Pa * 1 m^3/s = 1 N * 1 m/s = 1 V * 1 A = 1 W :) | |
| Oct 7, 2017 at 0:30 | comment | added | Anthony X | @andre not clear to me either how to calculate gain for a carbon microphone, but there is a relationship between sound pressure as it is applied to the carbon element and electrical resistance of the element. Acoustic energy is driving the time-varying pressure on the element; a DC input voltage is driving the line current through a time-varying resistance in the element. The acoustic energy itself doesn't drive the electrical signal, it only shapes the current driven by the power supply voltage. Like when you turn on a light - your finger on the switch doesn't power the light. | |
| Oct 4, 2017 at 6:01 | comment | added | andre314 | Totally agree. It is not clear for me how to calculate a power gain between a acoustic domain and a electric domain, but because "electrodynamic speaker coupled to a carbon microphone" has gain (purely electric), it is clear that something has gain, and this something is necessaly the microphone | |
| Oct 4, 2017 at 1:01 | history | answered | Anthony X | CC BY-SA 3.0 |