Patent EP-3151425-A1 (EP)
Inventor: NAWROCKI PIOTR
IPC: H03F3/185
Filed: 2015-09-30
Abstract: The invention relates to an electronic amplifier, in particular a microphone one, comprising a voltage amplifier, a voltage amplifier load and a voltage amplifier power supply, wherein 
¢ said voltage amplifier comprises two branches, each of which includes: 
- a transistor (T, T') of the MOSFET type; 
- a capacitor (C1, C1') with one end connected to the gate of said transistor (T, T'); 
- a capacitor (C2, C2 ') and a resistor (R1, R1') is connected to the drain of said transistor (T, T '), wherein said capacitor (C2, C2') and a resistor (R1, R1 ') are interconnected parallel; 
- a diode (D, D'), preferably a Zener diode, connected at one end to a source of said transistor (T, T') and the second end of the resistor (R2, R2') and the capacitor (C1, C1'), wherein the LED of (d) a first branch connected to the cathode of a source of the transistor (T) and the anode with a resistor (R2) and capacitor (C1) and the diode (D') of the second branch connects via the cathode to a source of the transistor (T') and via the anode with the resistor (R2') and the capacitor (C1'); 
- a resistor (R3, R3') connected to said resistor (R1, R1') and a resistor (R2, R2') 
wherein said branches are connected to each other by means of: 
- a resistor (R4) which at one end is connected to the resistors (R2) and (R3) of the first branch and the second end of the resistor (R2') and (R3') of the second branch, and 
- a resistor (R0), one end of which is connected to the cathode of the diode (D) and the source of the transistor (T) of the first branch and the anode of the diode (D') and the source of the transistor (T') of the second branch. 
and the capacitor (C1) of the first branch and the capacitor (C1') of the second branch are interconnected by ends remote from gate transistor (T), (T'); 
¢ said voltage amplifier power supply includes: 
- two PI filters, each of which comprises a transistor (R5, R5'), preferably with a value of 1©, coupled to a first side of the capacitor (C3, C3'), on the other-to the capacitor (C4, C4'); 
wherein the capacitor (C3) is connected to the capacitor C3' and the capacitor C4 is connected to the capacitor C4'; 
- a battery of electrolytic capacitors connected to the first side of the capacitor (C4) and the resistor (R5) of the first filter, on the other hand, the capacitor (C4 ') and the resistor (R5') of the second filter,  
¢ said voltage amplifier load includes the resistor Rn and the receiver of an audio signal connected to each other; 
wherein said voltage amplifier is adapted to attach it: 
- by input with an audio signal source through the capacitor (C1) with an end remote from the transistor (T) of the first branch and the capacitor (C1') with an end remote from the transistor (T') of the second branch, wherein the audio source is connected in parallel with the resistor (Rz), preferably with a value of 1M©. 
- with said power supply of the voltage amplifier by: 
ª the capacitor (C3, C3') and the resistor (R5, R5') connected with the resistor (R1, R1') and the resistor (R3, R3'), 
ª the resistor (R0), which is connected by the end remote from the transistor (T), (T') and the diode (D), (D') to the capacitor (C3) of the first branch and the capacitor (C3') of the second branch, and then with the capacitors (C4) of the first branch and the capacitor (C4') of the second branch, and further to ground.  
- with said load of the voltage amplifier by: 
ª the capacitor (C2) of the first branch and the capacitor (C2 ') of the second branch connected with the resistor (R) and the audio signal receiver.