Description. Here is a simple shock sensitive alarm circuit that has many many applications fro home to automobiles.The main application of this circuit is to use it as an anti theft alarm in automobiles.A peizo electric sensor is used as the shock sensor which has to mounted on the door which you have to protect. […]
Description. This micro flasher circuit continuously emits flashing light with the consumption of very less power.The circuit can run for a very long time for four 1.5 V torch cells. Here a low power CMOS IC CD4093 (IC1) is used to produce sharp pulses of 20 ms from a red LED.The LED appears to
Description. Here is a simple circuit for boosting 12 V DC to 24 V DC .The circuit is designed straight forward and uses few components.With few modifications the circuit can be used to boost any voltages. The transistor Q1 and Q2 (D1616) essentially drives the primary of the transformer.The diodes rectifies the output of transformer
 Description. Here is superb sound shifter circuit that can be used to add effects to the input sound signal.The circuit is ideal for incorporating in toys and adds great fun.The circuit can be also used in mixers and recorders. The circuit is based on IC HT 8950 from Holtek. The IC HT8905 is a single
Description. The IR to RF transmitter circuit given here can convert the IR signals from your remote to RF signals to long distances. The circuit given here is a good one for extending the range of your IR remote.Also such systems does not need a line of sight since RF signals are used. The transmitter
 Description. The automatic door handle alarm circuit gives a audible alarm and glows a LED when somebody touches the handle of the door.The circuit is latching type and continues to produce sound until it is switched off. The transistor Q1 is wired as an astable multivibrator whose output is used to bias transistor Q2 to
Description. Here is a simple 3 band graphic equalizer circuit made of a single op amp IC LF351 (IC1) and few passive components.The component values of this circuit are not very critical and can be replaced with nearest values with a little loss on the performance.This feature make it easy to be assembled from your
Description. Here is a simple and compact flasher circuit that an be used where ever a flashing LED is needed.The circuit finds application in flashing beacons,alarms automobile and more. The circuit is nothing but an astable multivibrator based on IC NE 555 (IC1).The frequency of the oscillation depends on the values of R1,R2 ,R3 and
Description. A very rugged and reasonably power amplifier circuit that can be used for any audio applications. The amplifier produces 60W rms at 50V supply on a 8 Ohm load.The circuit is designed such that most of the components are not critical and can be easily replaced by nearest values.This make it ideal to assemble
Description. Here is a handy field strength meter that can be used to check the strength of AM radio signals.The circuit is a very useful for those who assemble radio transmitters(especially in the tuning of the final stage for maximum range). The circuit is essentially some sort of a AM receiver it self. The capacitor
Description. Here is the schematic of a simple flouroscent lamp driver circuit based on two transistors.The circuit uses capacitive ballasting for driving the tube.An 8 W standard flouroscent tube can be efficiently driven using the circuit. The two transistors (2Sc 1983) with associated components forms a oscillator around 1KHz.The oscillator is wired so that saturation
Description. Here is the circuit diagram of a versatile FM transmitter that doesn’t have a coil. The circuit is simple and easy to assemble. The gate N1 acts as a buffer for strengthening the signals from the condenser microphone. The inverter N2 with its associated components forms a radio frequency oscillator in the FM region.The
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. A simple telephone transmitter circuit that is ideal for transmitting the telephone conversation through small distances.The circuit is very simple and uses only few components.The entire circuit can be easily included in the telephone itself or in the junction box.The circuit is powered from the telephone line itself. The transistor Q2 is wired as
Description. With this cool circuit integrated to your cars headlight system , you can drive cool headed in high beam.The circuit will take over the duty of low beaming the headlight when vehicles approach against , and high beams the lights when they pass over. The circuit is based on a photo transistor(Q1) for sensing
Description. The circuit depicted here can be used as an indicator when the telephone receiver is off-hook. The circuit can be in corporated with old telephones that does not have such an indicator. The circuit uses a complementary darling to pair using Q1 (2N3904)and Q2 (2n3906) to sense whether the receiver is off hook and
Description. The circuit diagram present here is that of a street light that automatically switches ON when the night falls and turns OFF when the sun rises. In fact you can this circuit for implementing any type of automatic night light. The circuit uses a Light Dependent Resistor (LDR) to sense the light .When there
Description. Here is the simplest scheme for converting a CD ROM drive of your computer to a Audio CD player. The minimum requirement for the player is that, it should have a audio output and skip button. Luckily most of the CD ROM’s are equipped with both of these. Â The CD ROM drive needs two
Description. Here is a simple fire alarm circuit based on a Light Dependent Resistor (LDR) and lamp pair for sensing the fire. The alarm works by sensing the smoke produced during fire. The circuit produces an audible alarm when the fire breaks out with smoke. When there is no smoke the light from the bulb
 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
How to make a 12V battery charger at home? Description Here is the circuit diagram of a simple and straight forward 12 V battery charger circuit with diagram. This circuit can be used to charge all type of 12V rechargeable batteries including car batteries. The circuit is nothing but a 12V DC power supply with
Description. Here is a simple IR headphone circuit that is suitable for listening to TV or radio with out disturbing others. For beginners the IR headset is a better option than FM head sets because they often produce desirable sound quality with out tuning as well as difficult impedance matching that is often done inÂ
Description. Here is the circuit diagram of 9 V regulator using popular 7809 IC. The 7809 is a 9 Volt voltage regulator IC with features such as internal current limit, safe area protection, thermal protection etc. A 16 V transformer brings down the 230V mains, 1A bridge rectifier rectifies it and capacitor C1 filters it
Description. 7805 is a 5V fixed three terminal positive voltage regulator IC. The IC has features such as safe operating area protection, thermal shut down, internal current limiting which makes the IC very rugged. Output currents up to 1A can be drawn from the IC provided that there is a proper heat sink. A 9V
