This long-range FM radio transmitter has an additional RF power amplifier stage, after the oscillator stage. The extra RF power amplifier used to strenght up the power output to become 200-250 milliwatts. With a great matching multi-element Yagi antenna or 50-ohm ground—plane antenna, this transmitter can give great good signal strength up to a distance… Read More »
This is a easy built and very low-cost circuit purposed to protect your electronic appliances / devices, such as Personal Computer, TV, recording devices, refrigerator, and other devices during sudden tripping and resumption of home mains supply. Appliances like refrigerators and air-conditioners are more inclined to damage due to such conditions.
This is a MicroChip Uninterruptible Power Supply (UPS) reference design with PIC17C43 microcontroller. The document is available to download from the end of this post. At times, power from a wall socket is neither clean nor uninterruptible. Many abnormalities such as blackouts, brownouts, spikes, surges, and noise can occur. Under the best conditions, power interruptions… Read More »
This easy to built circuit produces a warning beep when somebody crosses a secure area in your home or place of work. The transfer, hidden beneath the ground mat, causes the alarm whilst the individual walks over it. The circuit makes use of a behaviorive foam because the switch. it may be small items of… Read More »
Here the water-level indicator which use a 7-segment display, to show the water level (low, half and full) in the tank. Moreover, a buzzer is utilized to warn you of water overflowing from the tank. The circuit shows the water level by displaying L, H and F for low, half and full, respectively. The circuit… Read More »
Here the SW transmitter circuit based on IC BEL1895. This particular transmitter circuit works in shortwave HF band (6 MHz to 15 MHz), and can be applied for shortrange communication and for educational purposes. The circuit is composed of a mic amplifier circuit, a variable frequency oscillator, and modulation amplifier stages. Transistor T1 (BF195) is… Read More »
Here the circuit diagram of simple and easy made battery level indicator. In general, in mobile phones, the battery levels is displayed in dot or bar style. This helps you to effortlessly acknowledge the battery level. On this page we provide a circuit that helps you to recognize the battery level of a instrument from… Read More »
This is an easy, low cost and easy built circuit of an electronic horn which is designed close to quadruple op-amp IC LM3900 (IC1). IC LM3900 has four independent operational-amplifiers (A1 through A4) having a large output voltage swing. It is able to operate at up to 32V DC. The 1st op-amp (A1) is designed… Read More »
Here the long range/distance Infrared transmitter circuit, give you extra power for your Infrared transmitter. The majority of the IR remotes do the job reliably within a range of 5 metres. The circuit complexity increases in case you design the IR transmitter for good operation more than a extended distance, for example, 10 metres. To… Read More »