Light-sensitive Alarm Project

The circuit detects a sudden shadow falling on the light-sensor and sounds the bleeper when this happens. The circuit will not respond to gradual changes in brightness to avoid false alarms. The bleeper sounds for only a short time to prevent the battery running flat. Normal lighting can be used, but the circuit will work best if a beam of light is arranged to fall on the light-sensor. Breaking this beam will then cause the bleeper to sound. The light sensor is an LDR (light-dependant resistor), this has a low resistance in bright light and a high resistance in dim light.

Read more at: http://www.kpsec.freeuk.com/projects/lalarm.htm

Adjustable 1-10 Minute Timer Project

This circuit starts timing when switched on. A green LED lights to show that timing is in progress. When the time period is over the green LED turns off, a red LED turns on and a bleeper sounds. The time period is set by a variable resistor and it can be adjusted from 1 to 10 minutes (approximately). It could be used to set a time limit when playing games or as an egg-timer in the kitchen.
Read more at : http://www.kpsec.freeuk.com/projects/timer.htm

Simple Electronic Lock Project

There are six (or more) push switches. To 'unlock' you must press all the correct ones at the same time, but not press any of the cancel switches. Pressing just one cancel switch will prevent the circuit unlocking. When the circuit unlocks it actually just turns on an LED for about one second, but it is intended to be adapted to turn on a relay which could be used to switch on another circuit.

Read more at: http://www.kpsec.freeuk.com/projects/lock.htm

Simple Component and Continuity Tester

This simple project may be used for testing components, as well as checking circuit board tracks, wires and connections for continuity (conduction). It tries to pass a small current through the item being tested and the LED will light brightly, dimly or not at all according to the resistance of the item:
Read more at http://www.kpsec.freeuk.com/projects/simplet.htm

Traffic Light Project

This project operates red, amber and green LEDs in the correct sequence for a single UK traffic light. The time taken for the complete red - red & amber - green - amber sequence can be varied from about 7s to about 2½ minutes by adjusting the 1M preset. Some amber LEDs emit light that is almost red so you may prefer to use a yellow LED.

The 555 astable circuit provides clock pulses for the 4017 counter which has ten outputs (Q0 to Q9). Each output becomes high in turn as the clock pulses are received. Appropriate outputs are combined with diodes to supply the amber and green LEDs. The red LED is connected to the ÷10 output which is high for the first 5 counts (Q0-Q4 high), this saves using 5 diodes for red and simplifies the circuit. 

Read more at http://www.kpsec.freeuk.com/projects/trafficlight.htm

How to Make B.Tech project at low cost and make it best.

Do not try to copy entainr design or circuit. rather get inspreation.
Study the design carefully. do necessary survey about components that are available before you chose the project.
Make tings simple not so complicated
Make the project relevant to your subject.
Select project title carefully such that it should reflect your actual work on the project.
Make your project report your self. ant make it transparent.
remember project report is not an encyclopedia. 

PIC16F684 based Digital Amp Meter

This is a PIC microcontroller based Digital Amp Meter. It can measure AC or DC current up to 30A and display on 3 digits 7-segment with resolution 100 mA. The ACS712 from Allegro to be used for current sensing. It is designed for ease of use and no calibration required.[more]