I enjoyed reading this and especially liked the animation that shows the current flow.
acts like a short circuit) and the current freely flows between the Emitter and Collector. The electret microphone test circuit schematic is shown below: Fig. 2 - The test circuit for an electret microphone. To make a dB reading, you take a reference at one level, make your measurement at another level, then take the ratio. So I would net to know how much the voltage changes for example when the sound changes with one 1dB? Finally, we need one more component, a bypass capacitor between the Emitter terminal and the ground, thus CE. or do I actually have to measure that?
This component is known as capacitor. Keep in mind that the Base-Emitter voltage for the 2N2222A transistor is 0.7V and our power supply Vcc is going to be at least +3V. computer with an audio recording software (eg.
Think about it... 1V = 0 dBV, 0.1V is -20 dBV and 0.01V (10mV) is -40 dBV. According to the 2N2222A datasheet we should limit the circuit's components such that: When the transistor is OFF there is no current flow between Emitter and Collector which means that the voltage drop across the RL and RE is null.
Conventionally, 0dBA is the threshold of hearing, not easy to judge. - The microphone pre-amplifier circuit. Well, let's review quickly how a transistor works. Should I tell a colleague that he's serving as an editor for a predatory journal? I looked at some other pages on your site really liked them all.
In the next project I will create a small spy bug circuit that operates in the FM 87.5 - 108 MHz range because I intend to use a classical AM/FM receiver to pick-up the radio signal. The electret microphone JFET amplifier has the Gate connected to a pick-up plate (which is pushed back and forth by the air), the Source is connected to the ground and the Drain is connected to the output pin.