Inexpensive Car Protection Unit
For car protection, custom made units are available but they are costly. Here’s an inexpensive car protection unit to protect car stereo, etc. from...
Noise Muting FM Receiver
The tuning of a frequency modulated (FM) receiver to a FM radio station frequency involves a lot of ‘hissing’ noise in between the stations,...
Doorbell cum Visitor Indicator
This doorbell cum visitor indicator circuit can also give identification of the visitor to your home in your absence. When you’re home, you can...
PC Temperature Alarm
This circuit uses a temperature sensor to detect the temperature inside the PC and generates an alarm if the temperature exceeds a pre-set limit.
Automatic Lighting Fence
This circuit can sense the movement of a person within the range of three metres from a fence and produce a tone from the buzzer. This is used as a security system.
Automatic Off Timer For CD Players
This is a circuit that initiates a timer for turning off CD player as soon as the bedroom light is turned off.
BODMAS Rule
BODMAS rule is an acronym to help children to remember the order of operations in calculations.. The term BODMAS stand for bracket, of, division,...
Electronic Door Key
This circuit is basically a short-range, infrared remote-controlled electromagnetic relay driver. It can be used to control door motors or solenoid-based locks using a compact and handy remote handset.
Light Operated Doorbell
Light-dependent switches are used in automatic hand-dryers and flushers in toilets. Here is a simple light-operated switch that works in normal light also. You can affix it on the main door of your house to work as an automatic doorbell or a thief alarm.
DIAC Controlled Flasher
This simple flasher finds various industrial applications as a high-voltage indicator or machine-’on’ indicator. It flashes once every second to give a warning indication. It is simple to design and can be wired lead-to-lead without using PCB.
