Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
The right hand side of the capacitor is at 1.8 volts. The Left hand side of the capacitor is probably less than 1.8 volts due to the load the microphone presents. Therefore, the right hand side is probably more positive than the left hand side. The capacitor can be connected with the opposite polarity, but it will not function as it was designed to for long, as the dielectric film will deteriorate and possibly the foil plates will short circuit.
The right hand side of the capacitor is at 1.8 volts. The Left hand side of the capacitor is probably less than 1.8 volts due to the load the microphone presents. .
It could, theoretically, need to be reversed depending on the beta of the transistor and the type of mic. You could build the circuit without installing the capacitor, power it up, and measure the DC voltage of where the cap would be. Then install the cap with the correct polarity.
The 1uF capacitor is so big that it produces a cutoff frequency of 6Hz which is stupid.
Use a 330nF (0.33uF) film capacitor for 18Hz or 220nF (0.22uF) for 27Hz which does not have polarity.
The 1uF capacitor is so big that it produces a cutoff frequency of 6Hz which is stupid.
Use a 330nF (0.33uF) film capacitor for 18Hz or 220nF (0.22uF) for 27Hz which does not have polarity.
The cutoff frequency is when the resonse has dropped -3dB which is to 0.707 times the AC voltage. It is simply calculated by 1 divided by pi x R x C. The electret mic is about 3k ohms, the input impedance of the transistor is shown on its datasheet at the low current in this project and the 47k bias resistor is in parallel witrh the input impedance of the transistor.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
![1TrBugwith%20Slug[1].gif](/data/attachments/24/24701-6d00dc48b6ce2c845205945b798eaeb2.jpg)
