Electronic Circuits and Diagram-Electronics Projects and Design

Description. Here is a versatile remote controlled appliance switch that can ON or OFF any appliance connected to it using a TV remote.  IR remote sensor IC TSOP 1738 is used for recieving the signal. Normally when no signal is falling on IC3 the output of it will be high.This makes Q1 OFF.When a signal of 38 KHz from the TV remote falls on the IC3 its output goes low.This makes Q1 conduct and a negative pulse is obtained at pin 2 of IC 1  NE 555.Due to this IC1 wired as a monostable multivibrator produces a 4 Sec  long…

Descrption. This is a simple circuit in which the glowing LED can be switched OFF just by a puff. A condenser mic (M1) is used to sense your puff. When the push button S1 is pressed, the transistors Q2 and Q3 wired as latching pair gets activated and drives the LED to glow. The LED remains in this condition. When you puff on the condenser mic, the sound pressure is converted into a voltage signal at its output. This voltage signal will be amplified by the transistor Q1.Since the collector of the Q1 is coupled to the emitter of the…

Description. This simple circuit can be used as an aid for sensing the distance between the rear bumper of the car and any obstacle behind the car. The distance can be understood from the combination of the LEDs (D5 to D7) glowing. At 25cm D7 will glow, at 20 cm D7&D6 will glow and at 5cm D7, D6 and D5 will glow. When the obstacle is beyond 25 cm none of the above LEDs will glow. Two ICs are used in the circuit. The IC1 (NE555) is wired as an astable multivibrator for driving the IR Diode D1 to emit…

Description. Here is a simple yet powerful circuit that can be used for flashing 12V lamps especially that is used on automobiles.The flashing circuit is based on transistor Q1(BC557) and MOSFET Q2 (IRF530) where the Q2 provides the necessary drive for the lamp.Any number of bulbs can be flashed using this circuit provided that the total load must not exceed 42 Watts. Circuit diagram with Parts list. Notes.  Assemble the  circuit on a good quality PCB or common board. The circuit can be powered form the car battery itself. The switch S1 can be used as the ON/OFF switch. All…

Description. This timer circuit can be used to switch OFF a particular device after around 35 minutes. The circuit can be used to switch OFF devices like radio, TV, fan, pump etc after a preset time of 35 minutes. Such a circuit can surely save a lot of power. The circuit is based on quad 2 input CMOS IC 4011 (U1).The resistor R1 and capacitor C1 produces the required long time delay. When pushbutton switch S2 is pressed, capacitor C1 discharges and input of the four NAND gates are pulled to zero. The four shorted outputs of U1 go high…

Description. This circuit can be used to identify whether there is a clipping in a particular wave form. Clipping is a phenomenon in which the amplitude of a particular waveform drops before it reaches the expected limit. This circuit glows an LED as an indication if the signal under test has clipping. The circuit is very useful in sorting out distortion problems in amplifiers.   The circuit is based on a window comparator based on the two opamps inside the IC1 (TL082).The circuit detects the positive or negative peak value reached by the input signal. The output of the opamp…

Description. Here is a simple circuit that will produce a musical horn when ever your car is in reverse gear.The circuit uses two ICs for the operation, voltage regulator 7805(IC1) and musical tone generator UM66(IC2). The IC1 reduces the car battery voltage to 5V. The diodes D1 & D2 in combination  produces an additional  drop of 1.4 V to give a 3.6 V supply for the UM66. The supply voltage of UM 66 should not  be more than 4V. When ever the car is in reverse gear ,the reverse gear switch of the car gets activated and the circuit gets…

Description. Here is a simple circuit using IC NE555 that can be used to generate metronomes.Such a circuit is very useful to those who learns music. The circuit is nothing but an astable multivibrator wired around NE555 .The components R1,R2&C1 determines the output frequency. Circuit diagram with Parts list.  Notes.  The circuit can be wired on a general purpose PCB or common board. The circuit can be powered from a 9V PP3 battery. The POT R1 can be used to adjust the rhythm of the sound. The POT R2 can be used as volume control. The speaker k1 can be…

 Description. Here is a simple circuit diagram of a simple musical horn using two NE555 ICs. Two ICs are wired as astable mutivibrators. The output of first multivibrator is given to the discharge (pin 7) of the second astable multivibrator. The combined effect of the astable multivibrators produces a musical tone at the output.  Circuit diagram with Parts list. Notes.  The sound effect can be adjusted by varying the POTs R2&R5. The speaker can be a 8 Ohm tweeter. The circuit can be powered from a 9V PP3 battery. The ICs must be mounted on holders.  All capacitors must be…

Description. A high gain amplifier circuit that can be operated from a battery pack of 6 or 9 volt battery pack is shown here.The IC1 uA 741 is wired as a high gain non-inverting amplifier and its output is amplified by a pair of complementary transistors (Q1 & Q2) to drive the speaker.The negative feedback from the common emitter junction of the two transistor stabilizes the gain of the circuit.The resulting audio output is sufficient to serve as a signal tracer. Circuit diagram with Parts list. Notes. Assemble the circuit on a  good quality PCB or  common board . The…