Showing posts with label AUDIO AMPLIFIER. Show all posts
Showing posts with label AUDIO AMPLIFIER. Show all posts
Friday, November 2, 2012
Freeze Protector Circuit
This is the simple freeze protector circuit diagram. It is also called timing circuit. It is just hobby project for beginners. When you need to operate automatically any device in the fixed time later after coming AC power supply, you can use this circuit.
The voltage amplitude
is high when AC power come. Suddenly high voltage destroys the
electronics device. For this reason, in the time of load shedding we
need to switched off electronics device (Audio/Video player, CD/DVD
Player, TV, Freeze or any electronics device). This circuit solve this problem.
Hobby Electronics helps the beginners to know the timing circuit specially using 555 IC
timer. NE555 IC is the very simple well known parts. Its configuration
is very simple. You can use this timer any simple circuit.
In this circuit use 12volt
power supplies. 300k variable resistor is used for timing control.
Timing resistor and capacitor are 300k and 1000uF. Only change the value
of the variable resistor for your required timing.
The circuit output pin 3 is connected with resistor (10k) and output 12 volt relay. Relay is connected as figured with the device. Making cost is too low. Anyone can make this circuit easily.
Friday, September 23, 2011
AM Transmitter Circuit Diagram Using 741 Op-amp
AM transmitter is a circuit which can transmit message signal to modulated signal. This circuit is designed with limited power and the required power supply of the transmitter circuit is 9 Volt.
The circuit has three parts that is an audio amplifier, radio frequency oscillator and modulator circuit. The frequency oscillator is built with 741 Op-amp and related components. The carrier signal frequency and its amplitude can be varied using variable resistor accordance with VR1 and VR2 respectively. C1 and C2 are the main components to generate the carrier frequency.
Another part of the circuit is an audio amplifier circuit. The audio amplifier is built with 741 Op-amp and related components. A microphone is used to convert the voice signal to the audio signal which is feed to the op-amp’s inverting terminal. This audio signal is amplified by the op-amp. The amplified audio signal is filtered using the capacitor C7. This output is feed to the modulator circuit.
The main part of the AM transmitter is modulator circuit which is built with the transistor BC109. The carrier signal is feed to the base of transistor and the message / audio signal is also feed to the emitter of the transistor.
Here the required modulated signal is taken from the collector of the transistor which is feed to the output antenna.
Tuesday, August 23, 2011
POWER METER SCHEMATIC For AUDIO AMPLIFIER CIRCUIT DIAGRAM
POWER METER SCHEMATIC For AUDIO AMPLIFIER CIRCUIT DIAGRAM
When the speaker resistance is 4O, then, make R1=10kO, if the resistance of speaker is 8O, make R1=8kO, and if the resistance of speaker is 16O, make R1=30kO.
The absence of peak detector or the detector will of averages give the circuit a fast reading of instantenous power, and this Gives us insight of both average and peak condition. For more readable peak or average mesurement, you cans use peak or average detector circuit.
Sunday, July 10, 2011
8WATT AUDIO AMPLIFIER TDA2030 CIRCUIT SCHEMATIC DIAGRAM
This is a circuit of 8-watt audio amplifier IC TDA2030-based mono. When you use 4 ohm speakers then you get 14 watts output power, and around 8 watts if you use 8 ohm loudspeaker.
Although the TDA2030 is capable of delivering 20 watts of audio power, I deliberately reduced the output to about 8 watts to 10 watts drive speakers. This is more than adequate for a smaller room. Input sensitivity is 200mV. Higher input levels naturally will give greater output, but no distortion should be heard. The gain is set by the 47k and 1.5k resistors. The TDA2030 IC is affordable and makes a good replacement amplifier for low to medium audio power systems. Incidentally, it is speaker efficiency that determines how "loud" the sound is. Speaker efficiency or sound pressure level (SPL) is usually quoted in dB / meter. A speaker with an SPL of 97dB / m will sound louder than a speaker with an SPL of 95dB / m.
Absolute Maximum Ratings IC TDA2030
Supply voltage ± 18 (36) V
Input voltage Vs
Differential input voltage ± 15 V
Output peak current (internally limited) 3.5 A
Power dissipation at Tcase = 90°C 20 W
Tj Stoprage and junction temperature -40 to 150 °C
Friday, February 25, 2011
Simple AM Transmitter Circuit
AM transmitter circuit that can transmit your audios to your backyard.This circuit is designed with limited the power output to match the FCC regulations and still produces enough amplitude modulation of voice in the medium wave band to satisfy your personal needs. You will love this.
These components can be easily obtained from your old medium wave radio. Q1 is provided with regenerative feedback by connecting the base and collector of Q1 to opposite ends of the tank circuit. C2 ,the 1nF capacitance , couples signals from the base to the top of L1, and C4 the 100pF capacitance ensures that the oscillation is transfered from collector, to the emitter, and through the internal base emitter resistance of the transistor Q2 (BC 109) , back to the base again.
The resistor R7 has a vital part in this circuit. It ensures that the oscillation will not be shunted to ground trough the very low value internal emitter resistance, re of Q1(BC 109), and also increases the input impedance such that the modulation signal will not be shunted to ground.
Q2 is wired as a common emitter RF amplifier, C5 decouples the emitter resistance and unleashes full gain of this stage. The microphone can be electret condenser microphone and the amount of AM modulation can be adjusted by the 4.7 K variable resistanceR5.
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