Here the circuit diagram of electronic siren based NE555. This circuit produces a sound like factory siren. It applies a 555 timer IC which is utilized as an astable multivibrator of a center frequency of about 300Hz. The frequency is controlled by the pin 5 of the IC. When the power supply is switched ON,… Read More »
The following circuit is a simple fire alarm circuit based NE555 timer and use thermistor as a temperature detector. This sensor will activate the transistor when the temperature is in high value. The thermistor will have a low resistance at high temperature, while at low temperature, the transistor resistance is high. This characteristic of thermitor… Read More »
This easy electronic buzzer circuit built based on timer works for gaining the frequency. The IC timer NE 555 used as astable multivibrator operating at about 1kHz and produces a sound when switched on. The sound frequency can be adjusted by varying the 10K resistor. You may change the 10K resistor with variable resistor.
The flasher circuit (Second Circuit) is worked around clock NE555, which is wired as an astable multivibrator that yields square wave at its pin 3. A 10W auto bulb is utilized for flasher. The blazing pace of the bulb is chosen by preset VR1.
This is a basic circuit of car horn and lamp flasher that starts playing the vehicle horn at whatever point your vehicle is backward rigging. The circuit (First Diagram) utilizes double clock NE556 to create the sound. One of the clocks is wired as an astable multivibrator to produce the tone and the other is… Read More »
This is a really simple smoke alarm circuit design. The circuit consists of two important modules that are sensor module using a photo interrupter module and alarm module using a tone generator IC NE555 with astable multivibrator configuration and then connected to the speaker, so you can hear the alarm sound.
This is the circuit design of the protector for electronic appliance with three-phase power supply. Many of electronic appliances need three-phase AC supply to work. If there is any failure of any of the phases, then it will make the appliance prone to erratic functioning and may even lead to failure. Hence it is of… Read More »
Automatic Emergency Light Project. When mains is absent, relay RL2 is in deenergised state, feeding battery supply to inverter section via its N/C contacts and switch S1. The inverter section comprises IC2 (NE555) which is used in stable mode to produce sharp pulses at the rate of 50 Hz for driving the MOSFETs. The output… Read More »
Here is the schematic diagram of digital DC voltmeter built based IC ICL7107. The power supply for this circuit is +5V. You may use 9V battery and then use regulator IC LM7805 to achieve 5V stabilized voltage. This circuit will be good to display your power supply output.