Here the notebook anti theft protector circuit to secure your important netbook / notebook from stealing. Basically, this is a mini security alarm generator. Fixed inside the notebook case, it will definitely sound a noisy alarm when a person attempts to grab the notebook. This very sensitive circuit utilizes a homemade tilt switch to turn… Read More »
This is simple to build and cheap motorcycle alarm circuit which could be fitted in motorcycles to take care of them from getting stolen. The tiny circuit may be hidden anyplace, without having any difficult wiring. Practically, it fits all motorcycles as long as they’ve a electric battery. It is not going to drain out… Read More »
This is the 220V / 200W lamp flasher circuit diagram. The frequency/speed of the lamp flashing can be adjust with the range of 1Hz to 5Hz. You can use the PR1 variable resistor (trimpot) to adjust the flashing speed. The duty cycle of lamp flashing can be adjusted using PR2 variable resistor.
This is really a very simple home telephone ring tone generator circuit which is built with applying only several electronic components / parts. It generates simulated telephone ring tone and requires only DC supply with 4.5V DC to 12V DC voltage. One may possibly use this circuit in ordinary intercom or phone-type intercom. The sound… Read More »
Here the simple schematic of multitone siren alarm circuit. This multitone siren is effective for reverse horns, burlgar alarms, and many others. It generates five various audio tones and is much more earcatching than a single-tone siren.
This is definitely an ultra-sensitive fire sensor that exploits the direct piezoelectric property of an ordinary piezo component to recognize the fire. The lead zirconate titanate crystals within the piezo component have the property to deform and produce an electrical potential when heated, thus converting the piezo component into a heat sensor. The circuit mentioned… Read More »
Here the simple Mini UPS circuit diagram. This circuit can provide an uninterrupted power supply (UPS) to operate 12V, 9V and 5V DC-powered instruments at up to 1A current. The backup battery will take up the load with no spikes or delay when the mains electrical power gets interrupted. It could possibly also be utilized… Read More »
This is the FM transmitter circuit which apply 4 radio frequency stages, that are a VHF oscillator designed around transistor BF494 (T1), a preamplifier designed around transistor BF200 (T2), a driver designed around transistor 2N2219 (T3) and also a power amplifier designed around transistor 2N3866 (T4). A condenser microphone is wired at the input of… Read More »
Parts List: R1-2-4-5=270Ω R3 = 2.7Ω VR1 = 10KΩ Log. Pot. TR1 = 470KΩ Trimmer IC1-2 = LM388 C1 = 100uF/25V C2 = 100nF C3 = 10uF/25V C4-5 = 22uF/25V C6 = 47nF