My Circuit

Using this circuit, you can change the speed of the fan from your couch or bed. Infrared receiver module TSOP1738 is used to receive the infrared signal transmitted by remote control. The circuit is powered by regulated 9V. The AC mains is stepped down by transformer X1 to deliver a secondary output of 12V-0-12V. The transformer output is rectified by full-wave rectifier comprising diodes D1 and D2, filtered by capacitor C9 and regulated by 7809 regulator to provide 9V regulated output. Any button on the remote can be used for controlling the speed of the fan. Pulses from the IR receiver module are applied as a trigger signal to timer NE555 (IC1) via LED1 and resistor R4. Remote-Controlled Fan Regulator Circuit Diagram Remote-Controlled Fan Regulator Circuit Diagram IC1 is wired as a monostable multivibrator to delay the clock given to decade counter-cum-driver IC CD4017 (IC2).Out of the ten outputs of decade counter IC2 (Q0 through Q9), only five (Q0 through Q4) are used to control th...

This circuit is for a temperature controlled constant current battery charger. It works with NICD, NIMH, and other rechargeable cells. The circuit works on the principle that most rechargeable batteries show an increase in temperature when the cells becomes fully charged. Overcharging is one of the main causes of short cell life, hot cells pop their internal seals and vent out electrolyte. As cells dry out, they lose capacity. Theory The transformer, bridge rectifier, and 1000uF capacitor provide around 22 Volts of DC power to run the rest of the circuit. The 7812 regulator drops this to 12V to run the 311 comparator and 4011 nand gates. The start switch is pressed to start the charging cycle. This causes the two 4011 nand gates, which are wired as an r-s flip-flop, to go into the charging mode. The Red LED is lit, and the VMOS FET current switch is turned on. Charging current runs though the battery pack. If the battery starts out warmer than the reference temperature, the circuit wil...

In this circuit the 555 timer is used in a novel way, as a voltage controlled switch.The old and omnipresent NE555 can be very good at something it was not meant for: driving relays or other loads up to 200 mA. The picture shows an example circuit: if the input level rises over 2/3 of the supply voltage - it will turn on the relay, and the relay will stay on until the level at the input drops below one third of the supply voltage. If the relay and D1 were connected between pin 3 and ground, the relay would be activated when the input voltage drops below one third, and deactivated when the input voltage goes over two thirds of the supply voltage. It is also a nice advantage that the input requires only about 1 uA, which is something bipolar transistors can't compete with. (This high impedance input must not be left open.) A large hysteresis makes the circuit immune to noise. The output (pin 3) can only be either high or low (voltage-wise), and it changes its state almost instantenou...

             This project is a robot vehicle that can be controlled through any computer wirelessly using a WiFi link. It transmits real-time video to the controlling computer using the same link. The video transmitting camera mounted on it. It also has obstacle detection,temperature,sound and light sensitivity feature.           Usually robots are controlled through a laptop using an WiFi link which is subject to attenuation, noise and has a very limited range as well. This project features a robot that uses WiFi 802.11G standard for its control signals through TCP/IP protocol, which has flow control. This enables uninterrupted and reliable transmission of control signal to the robot vehicle. WiFi support high data rates which enables good quality uninterrupted video transmission from the robot to the computer. Image capturing is done by mounting an IP-camera over the Robotic Car. Obstacle detection is done...