ELECTRONICS CIRCUIT PROJECTS

20W HiFi Power Amplifier Using TDA2040 circuit diagram
This is a Hi-Fi power amplifier circuit build based on single power amplifier IC TDA2040. The single TDA2040 has able to deliver 20W power output. The bridge amplifier which consist of double TDA2040 can deliver 30W power output (8 ohm loudspeaker).

The single TDA2040 has able to deliver 20W [...]

The 75 Meter QRP SSB Transceiver Theory of Operation 6-30-03
In general, the transceiver switches the 4-element 1500 ohm xtal BPF ends between the inputs and outputs of the two SA602s to reverse the signal flow for R/T operation. Since no IF amplifier is used in the design, 20 dB of additional receiver gain is produced [...]

P1____    22K  Log. Potentiometer
R1___     22K  1/4W Resistor
R2,R3____ 100K  1/4W Resistors
R4___     47K  1/4W Resistor
R5_____   2K2 1/4W Resistor (See Notes)
R6_____   6K8 1/4W Resistor
R7________22K  1/2W Carbon or Cermet Trimmer
R8_______ 2K7 1/4W Resistor
C1,C6_____100nF  63V Polyester or Ceramic Capacitors
C2,C3___ _10µF  63V Electrolytic Capacitors
C4________22µF  25V Electrolytic Capacitor
C5________22nF  63V Polyester or Ceramic Capacitor
C7________470µF  25V Electrolytic Capacitor
Q1_________BC547  45V 100mA NPN Transistor
IC1________TDA7052  Audio power [...]

The input, effects and output connections are shown

Input – these are quite the opposite of what you might think. The same basic idea is used on Fender amps, as well as nearly all others that have dual inputs for a channel. The Hi input is used for normal (relatively low output) guitar pickups, and is [...]