Digital & Analog Based Mini Projects Page_1
1. Anti sleep Alarm for Students:
This
circuit saves both time and electricity for students. It helps to prevent them
from dozing off while studying, by sounding a beep at a fixed time interval,
say, 30 minutes. If the student is awake during the beep, he can reset the
circuit to beep in the next 30 minutes. If the timer is not reset during this
time, it means the student is in deep sleep or not in the room, and the circuit
switches off the light and fan in the room, thus preventing the wastage of
electricity.
2. Accurate Electronic Stop-Watch:
Here is a simple circuit which can be used as
an accurate stop-watch to count up to 100 seconds with a resolution of 0.01
second or up to 1000 seconds with a resolution of 0.1 second. This stop-watch
can be used for sports and similar other activities.
3. Anti-Bag-Snatching Alarm:
Here is a simple alarm circuit to
thwart snatching of your valuables while travelling. The circuit kept in your
bag or suitcase sounds a loud alarm, simulating a police horn, if someone attempts
to snatch your bag or suitcase. This will draw the attention of other
Passengers
and the burglar can be caught red handed.
4. Anti-Collision Rear Light:
During poor visibility, i.e., when there is
fog, or at dawn or dusk, or when your vehicle gets stalled on a lonely stretch
of a highway, this flashing light will provide safety and attract the attention
of people to help you out. It uses high brightness yellow LEDs.
5. Aquarium Probe:
A number of environmental factors including
light and temperature affect fish culture.
The temperature
of water has profound effect because fish cannot breed above or below the
critical temperature limits. Temperature between 24°C and 33°C is found to be
the best to induce spawning in fishes. This particular temperature range is
also necessary for the healthy growth of nursery fish fries (young fishes).
Rise of water temperature due to sunlight may adversely affect the fish rearing
process.
6. Automated Alarm Circuits Bird-Chirping
Sound:
Alarm
circuits are presented here. One produces bird-chirping Sound tone. The circuit
of the bird chirping- sound alarm unit along with the circuit of the control
unit.
7. Automatic Light Controller:
Voltage regulator ICs (78xx series) provide a
steady output voltage, as against a widely
Fluctuating input
supply, when the common terminal is grounded. Any voltage about zero volt
(ground) connected in the common terminal is added to the output voltage. That
means the increase in the common terminal voltage is reflected at the output.
On the other hand, if the common terminal is disconnected from the ground, the full
input voltage
8. Automatic Night Lamp With Morning Alarm:
This circuit automatically turns
on a night lamp when bedroom light is switched off. The lamp remains ‘on’ until
the light sensor senses daylight in the morning. A super-bright white LED is
used as the night lamp. It gives bright and cool light in the room. When the
sensor detects the daylight in the morning, a melodious morning alarm sounds.
9. Automatic Phase Changer:
In three-phase applications, if low voltage is
available in any one or two phases, and you want your equipment to work on
normal voltage, this circuit will solve your problem. However, a proper-rating
fuse needs to be used in the input lines (R, Y and B) of each phase. The
circuit provides correct voltage in the same power supply lines through relays
from the other phase where correct voltage is available. Using it you can
operate all your equipment even when correct voltage is available on a single
phase in the building.
10. Automatic Room Power Control:
An ordinary automatic room power control
circuit has only one light sensor. So when a person enters the room it gets one
pulse and the lights come ‘on.’ When the person goes out it gets Another pulse
and the lights go ‘off.’ But what happens when two persons enter the room, one
after the other? It gets two pulses and the lights remain in ‘off’ state. The
circuit described here overcomes the above-mentioned problem. It has a small
memory which enables it to automatically switch ‘on’ and switch ‘off’ the lights
in a desired fashion. The circuit uses two LDRs which are placed one after
another (separated by a distance of say half a meter) so that they may
separately sense a person going
No comments:
Post a Comment