Flashing LED

Alternate red and green flashing LED using 9 volt battery Part list R1,R2 – 100 Ohm R3,R4 – 105 K C1,C2 – 10 μF 25 Volt T1-T2 – BC 548 D1-D5 – Red LED D6-D10 – Green LED 9 Volt Battery

Dark Sensor

Dark Sensor

Dark sensor using 2 transistor BC547 When light falls on LDR, its low resistance drives the transistor T1 into conduction. This keeps transistor T2 cut-off due to low base bias. The LED does not get power as long  as ambient light…

Electrical Appliance Protection

Electrical Appliance Protection

This simple circuit of electrical appliance protection  is to protect your electrical appliance during irregular power supply. Normally when power goes off we forget switching off our appliances. Especially in India where power cuts are very frequent we tend to leave…

USB Reading Lamp

USB reading lamp is powered using USB port. The USB port provide 5 v and 100mA which is sufficient for this circuit. Cut the one end of the USB cable and use RED(pin1) and Black(pin4) for 5v positive and negative…