Download Dhananjay Gadre

Lighting and Instrumentation
Dhananjay V. Gadre
Netaji Subhas Institute of
Technology, New Delhi, India
http://www.nsit.ac.in
http://dvgadre.com
Electrical Power Problems
• Rural areas with electrical power shortage
• Pabal Fablab gets 10-12 hours every day
• Typical village in North India: 3 hours
every other day
Lighting Solutions
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LED lighting solutions
100,000 hours of operation
High power LEDs (3W) available
Twice as efficient as traditional lighting
solutions
• Cost getting low all the time
LED Lantern
• Sealed battery- 6V/5AH
• Ability to charge the battery with
overcharge protection
• Luminosity comparable to 11W CFL
• Parts cost < 10$
Derivatives
• Open source hardware and software
• Encourage local people to get into opening
small businesses to produce the lanterns
Instrumentation
• Instrumentation for healthcare,
measurement etc.
• Genesis in Dr. Kalbag at Pabal needing a
mechanism to measure milk quality.
• Neil came up with this possible solution
Step Response Measurement System
• Applies Voltage step across probes to be
inserted in milk
• Tiny Micro measures time response with an
on-chip ADC with undersampling
• Equivalent to swept frequency measurement
system to measure gain and phase.
• Problem of a unipolar voltage step
polarizing the milk/liquid has been solved
with a bipolar mechanism.
• Need substantial measurements to conclude
whether this is a feasible method
Low cost Instrumentation
• Idea of sub-1$ computational engine is very
attractive
• Use 8-pin Micro with 6 I/O pins
• Display usually a go/nogo type
• Large display means migration to a bigger
and more expensive micro
Miserly Display
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Use Charlieplexing
For N o/p lines, allows N*(N-1) LEDs
Can be arranged in 7-segment format
Allows 2-1/2, 2-3/4 or even 2-4/5 display
with 5 o/p lines
• Allows 1 line with analog or digital input
for relevant sensor