NE555 Electronic Buzzer Schematic
This accessible cyberbanking buzzer ambit congenital based on timer works for accepting the frequency. The IC timer NE 555 acclimated as astable multivibrator operating at about 1kHz and produces a complete back switched on. The complete abundance can be adapted by capricious the 10K resistor. You may change the 10K resistor with [...]

Fire Alarm Circuit Using LDR
Here is a simple fire alarm circuit based on a LDR and lamp pair for sensing the fire.The alarm works by sensing the smoke produced during fire.The circuit produces an audible alarm when the fire breaks out with smoke.
When there is no smoke the light from the bulb will be [...]

Many fire alarm circuits are presented here,but this time a new circuit using a thermistor and a timer to do the trick. The circuit is as simple and straight forward so that , it can be easily implemented.The thermistor offers a low resistance at high temperature and high resistance at low temperature. This phenomenon is [...]