Automatic Bathroom Light

This is a circuit of automatic bathroom light which can be used to automate the working of a bathroom light. It is designed for a bathroom fitted with an automatic door-closer, where the manual verification of light status is difficult. The circuit also indicates whether the bathroom is occupied or not. The circuit uses only two  ICs and can be operated from a 5V supply. As it does not use any mechanical contacts it gives a reliable performance.

PC Based Wireless Stepper Motor control Circuit

Stepper motors find lots of applications in process control, machine tools and robotics. Especially in robotics and process control, bit is necessary to control the stepper motor from a remote place. Here you will get the transmitter and receiver circuit diagrams and Full source code for the application program.

Here we describe how to wirelessly control a stepper motor from a remote place by using RF modules. For this wireless stepper-motor control system, you need to design and develop the required hardware and software. The parallel port of the PC is used to control the direction of the stepper motor at the transmitter side. RF interface is used instead of IR to overcome all the drawbacks of the IR interface. The PC signals are transmitted from the RF transmitter and received by the RF receiver.

Seismic Sensor Circuit

This circuit is a very sensitive seismic sensor that detects vibrations/sounds. It can detect seismic vibration or sounds caused by animals or humans. So it can be used to monitor protected areas to restrict entry of unwanted persons or animals.

Laser Switch With Timer

This circuit is a laser controlled relay switch with timer that can be made using readily available components. This laser switch has the following advantages :

• Timed operation - Turn on time of the switch can be controlled
• Large current handling capability, can control a motor
• Stand by and operating mode led indication
• operating mode Piezo alert.

Servo Motor Tester Circuit

This circuit allows you to isolate the servo motor from the project circuit and feed it with pulses of varying width nd checking the angle that the servo motor turns to. the circuit is built using two NE555 IC's and a few discrete components. IC1 is set as an astable multivibrator with a time period of 20 ms. Every 20 ms, the astable provides a very sharp negative pulse to trigger IC2. Timer IC2 is configured as a monostable multivibrator that produces 1ms, 1.5ms and 2ms long pulses to rotate the servo motor (M1). 

Car Reverse Horn With Flasher

This is a circuit of car reversing horn with normal auto lamp flasher that uses timer ICs NE556 and NE555. When the car is in reverse gear, the switch S1 which is the reverse gear switch of the car get shorted and the monostable timer give a high output. So the diode D1 and D2 goes for high for a time period R4C4. 

Portable Electric Lamp cum LED Flasher

Here's the circuit of a portable type flasher uses 25W, 230V AC bulb and nine LEDs. The bulb and led's glows alternatively. The circuit includes a 555 timer based astable multivibrator which generates a square wave. This output drives the transistor bc547 to riger the gate of lamp controller triac.