HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
78RPM
User Rank
Platinum
Would a constant current source help?
78RPM   10/16/2012 10:38:46 AM
NO RATINGS
It's impossible to read the documentation but I'm responding to your problem with inconsistent linearity of photocells.  Yes, photocells are imprecise and non-linear. Much of the voltage appears across the limiting resistor. Consider putting a transistor as a constant current source in series with photocells, eliminating the resistor. The voltage across the transistor will be a consistent two diode drops. That way, all the voltage change appears across the photocell. I hope I have understood your problem.

johnmoran
User Rank
Iron
Instructions ...
johnmoran   1/20/2012 10:03:15 AM
NO RATINGS
Hello

You may be an engineering student but your instruction writing skills are appalling - please try to get all the images the same size, then people may be able to read them.

John



Partner Zone
Latest Analysis
Earlier this year paralyzed IndyCar drive Sam Schmidt did the seemingly impossible -- opening the qualifying rounds at Indy by driving a modified Corvette C7 Stingray around the Indianapolis Motor Speedway.
As companies rush into IoT connectivity, the choice of doing it yourself or using a platform from a service company becomes a major issue.
Wearables are changing the way we see ourselves. With onboard sensors that have access to our bodies, we are starting to know our physical selves like never before, quantifying our activity, our heart rate, breathing, and even our muscle effort.
Last week, the bill for reforming chemical regulation, the TSCA Modernization Act of 2015, passed the House. If it or a similar bill becomes law, the effects on cost and availability of adhesives and plastics incorporating these substances are not yet clear.
This year, Design News is getting a head start on the Fourth of July celebration. In honor of our country and its legacy of engineering innovation -- in all of its forms -- we are taking you on an alphabetical tour through all 50 states to showcase interesting engineering breakthroughs and historically significant events.
More:Blogs|News
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Jul 6 - 10, Building Raspberry Pi Controllers with Python
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service