NE567 Â tone decoder / PLL IC. NE567 is a tone decoder IC from Philips. The IC has a built in PLL circuit with AM lock detection and an output driver circuit. The main function of NE567 is to drive a load (usually LED) when a frequency with in its detection band is available at the […]
LM1830 based liquid level indicator circuit. LM1830 is a monolithic integrated circuit that can be used in liquid level indicator / control systems. Manufactured by National Semiconductors, the LM1830 can detect the presence or absence of polar fluids . Circuits based on this IC requires minimum number of external components and AC signal is passed
Description. Here is the circuit diagram of a very simple and accurate electronic compass using the 1490 digital compass from Dinsmore. The 1490 digital compass is a solid state Hall Effect device which is sensitive to detect the Earth’s magnetic field. The sensor is internally damped to simulate the performance of an ordinary compass. The
Description. The circuit is nothing but two LEDs (D1 and D2), whose status are controlled by the temperature of the surroundings. The famous IC LM35 is used as the temperature sensor here. Output of LM35 increases by 10mV per degree rise in temperature. Output of LM35 is connected to the non inverting input of the
Description. This simple circuit will produce an alarm whenever the temperature falls below zero degree. A thermistor is used here to sense temperature. The op-amp LM7215 is used to compare the reference voltage and voltage from the thermistor network. Reference voltage is given to the non inverting input (pin3) of the IC and voltage from
Description. This is a simple and low cost wide band VHF field strength meter. The field strength is measured by converting the radio signal to DC and measuring it. The RF signal will be picked up by the coil and rectified by the diode D1.Even a very small DC voltage is sufficient to alter the
Notes. This is a very simple circuit that can be used to sense electromagnetic radiations. The circuit can even detect hidden wrings. A 1mH inductor is used for sensing the electric field. The electric field will induce a small voltage in the sensor inductor and this induced voltage is amplified by the opamp.The headphone connect
Description. This is a simple single chip metal detector circuit based on IC CS209A from the Cherry Semiconductors. A 100uH coil is used to sense the presence of metal. The IC CS209A has a built in oscillator circuit and the coil L1 forms a part of its external LC circuit which determines the frequency of
Description. A simple touch switch circuit using CD4011 is given here. The IC CD4011 is wires as a flip flop here. The 9, 13 pins of the IC works as the set and reset contacts respectively.CMOS ICs like 4011 require requires a very low current for controlling its gates. Since the pins 9 and 13
If you are looking for a Water level indicator or a Water level controller, there are pretty good circuits we have developed. This one is just a fun project made for hobby purpose! You can call this a water sensor circuit for sure! Description. This is a simple musical alarm circuit which produces a musical
Description. Here is a simple water level alarm circuit using 555 timer that will produce an audible alarm when the water level reaches a preset level.The circuit can be powered of a 3V battery and is very handy to use. The circuit is based on an astable multivibrator wired around IC1 (NE 555).The operating frequency
Description. This circuit can give a visual indication of the rate of air flow.It can be also used to check whether there is air flow in a given space. The filament of a incandescent bulb is the sensing part of the circuit.When there is no air flow the resistance of the filament will be low.When
Description. Here is the circuit diagram of a magnetic proximity switch that finds a lot of applications in many fields.The circuit is based on a magnetic reed switch(S1) as the proximity sensor. A monostable multivibrator based on NE555 (IC1) and a toggle flip flop based on CD4013 (IC2) does the rest of the circuit. When
 Description. Here is a simple mains power failure alarm/detector circuit that produces an alarm whenever the mains supply fails. Lot of such circuits are available, but the peculiarity of this circuit is that it requires no back up power source like a battery to power the alarm when the mains is absent. When there is
Description. Here is a simple circuit that can be used to switch ON or OFF a device when the dew present in the surrounding atmosphere crosses a set value. The circuit uses a dew sensitive resistive element and a comparator based on LM 358 to perform the above said operation. At normal condition the resistance
Description. Here is a straight forward, yet effective digital temperature controller that can be used with temperature control systems. The circuit uses IC LM 35 (IC3) to as the temperature sensor. The output of LM 35 is given to the IC ADC 0804 (IC4) which converts the analog output of the LM 35 to digital
