apricot_star
New Member
To design a 1W Audio Amplifier with mute and volume control. The design should allow end-user to select two different bandwidths, namely voice and music. The selected choice must be indicated visually using LEDs.
The power supply line to the audio amplifier is a ±12V line from the secondary of the 100KHz switching mode power supply. As the high frequency component may be present in the ±12V line, sufficient filtering is to be ensured.
The input signal to the audio amplifier is derived from the sound demodulated output of the SIF stage. The level of the base-band signal is 250mVp-p at 1kHz. (A function generator is to be used during testing).
The end-user has a choice of selecting voice, music or mute mode. This could be done via the remote control which sends an appropriate 2-bit signal to a transistor switching circuit. The supply to the transistor switching circuit is 5V. The 2-bit signal will be simulated using SPDT switches.
Assume that the input signal is already at music bandwidth.
The following components might be used are:
ICs: µA741; TDA7052A
Regulators: LM78L05 and LM78L08
Potentiometers: 1K, 10K, 100K, 1M, 2M
Transistors: 2N2222; 2N3904
Resistors: 10; 100; 1K; 3.3K; 4.7K; 5.6K; 10K; 22K; 100K; 1M
Capacitors: 1nF; 10nF; 0.1uF; 0.33uF; 0.47uF; 1uF; 4.7uF; 220uF
Switches: SPDT
LEDs: Red, Green and Yellow
Anyone knows how the circuit digram will look like in order to fulfil the specification?
Thxs!
The power supply line to the audio amplifier is a ±12V line from the secondary of the 100KHz switching mode power supply. As the high frequency component may be present in the ±12V line, sufficient filtering is to be ensured.
The input signal to the audio amplifier is derived from the sound demodulated output of the SIF stage. The level of the base-band signal is 250mVp-p at 1kHz. (A function generator is to be used during testing).
The end-user has a choice of selecting voice, music or mute mode. This could be done via the remote control which sends an appropriate 2-bit signal to a transistor switching circuit. The supply to the transistor switching circuit is 5V. The 2-bit signal will be simulated using SPDT switches.
Assume that the input signal is already at music bandwidth.
The following components might be used are:
ICs: µA741; TDA7052A
Regulators: LM78L05 and LM78L08
Potentiometers: 1K, 10K, 100K, 1M, 2M
Transistors: 2N2222; 2N3904
Resistors: 10; 100; 1K; 3.3K; 4.7K; 5.6K; 10K; 22K; 100K; 1M
Capacitors: 1nF; 10nF; 0.1uF; 0.33uF; 0.47uF; 1uF; 4.7uF; 220uF
Switches: SPDT
LEDs: Red, Green and Yellow
Anyone knows how the circuit digram will look like in order to fulfil the specification?
Thxs!
