Author Archives: admin

Clock Project Links

Posted on March 28, 2011 by admin

counter datasheet with circuit to use a 32.768Khz crystal: http://www.datasheetcatalog.org/datasheets/90/109006_DS.pdf interfacing to a 7-segment decoder: http://www.thelearningpit.com/lp/doc/7seg/7seg.html 4511 datasheet: http://www.datasheetcatalog.org/datasheet/philips/HEF4511BN.pdf  

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Ebay

Posted on March 9, 2011 by admin

We will only ship to PayPal’s Confirmed Address. This auction is for 5 pieces of 3W White LEDs mounted on stars   Specifications: Intensity:                129.5~147.7 Lumins Viewing Angle:         140° Forward Voltage:      3.2V-3.8V Forward Current:      700mA @ 25C° Color Temp:            5500K … Continue reading →

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Electronics

Posted on March 8, 2011 by admin

ROTARY ENCODER – a rotary switch that just keeps turning – uses gray code An LED can be used as a photodiode used for light detection as well as emission. http://en.wikipedia.org/wiki/LED_circuit     A cathode is an electrode through which … Continue reading →

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coulomb

Posted on March 7, 2011 by admin

The coulomb (symbol: C) is the SI derived unit of electric charge, transported by a steady current of one ampere in one second. 1C = 1A * 1s One coulomb is also the amount of excess charge on the positive … Continue reading →

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Power MOSFET Subcircuit

Posted on March 6, 2011 by admin

The MOSFET power output portion of the circuits used in various projects on this site serves to increase their power handling capacity. MOSFET (Metal Oxide Semiconductor Field Effect Transistor) – A voltage controlled transistor for amplification and switching. The circuits … Continue reading →

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MOSFET Gate Resistors

Posted on March 4, 2011 by admin

General Information on MOSFET characteristics with a good summary of gate charge calculations – http://www.irf.com/technical-info/appnotes/mosfet.pdf MOSFET gate ringing reduction with gate resistors – http://hmin.tripod.com/als/ccs/docs/pdf/Fairchild_AB-9.pdf Forum threads on MOSFET gate charge and resistors: http://www.edaboard.com/thread29231.html http://www.edaboard.com/thread165570.html

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Hello world!

Posted on March 3, 2011 by admin

Welcome to WordPress. This is your first post. Edit or delete it, then start blogging!

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555 Timer LED Blinking Circuits Part 1

Posted on January 1, 2011 by admin

       

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Adjustable 555 Timer Based PWM Circuit

Posted on January 1, 2011 by admin

A 555 timer is used to control the speed of a DC motor with pulse width modulation. A potentiometer controls the rate at which the timing capacitor charges and discharges which alters the duty cycle. This circuit is based on … Continue reading →

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Non-Adjustable 555 Timer Based PWM Circuit

Posted on January 1, 2011 by admin

A two-part video series covering how to use a 555 timer to control an electric motor with pulse width modulation. The circuit covered has a fixed duty cycle, but is expanded upon in the video attached to Adjustable 555 Timer … Continue reading →

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