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Wednesday, July 23, 2014

"Three Fives" Discrete 555 Timer Kit by Evil Mad Scientist

The Evil Mad Scientist Shop has the "Three Fives" Discrete 555 Timer kit designed by Eric Schlaepfer. The "Three Fives" Discrete 555 Timer kit is a replica of the NE555 timer; more over, a full functional transistor-scale replica. The NE555 Timer was designed in 1971 by Hans Camenzind and is featured in IEEE Spectrum, May 2009 article "25 Microchips That Shook the World". The NE555 chip is so popular because it has three operating modes: Monostable, Astable, and Bistable. These three operating modes allow the NE555 chip to be used in a large variety of electronic products just a few are delay timers, alarms, logic clocks, LED and lamp flashers, and power supplies. I enjoyed assembling the "Three Fives" Discrete 555 Timer kit. I also like the fact that the "Three Fives" Discrete 555 Timer can be dropped into a circuit design that requires a 555 Timer chip. I find that it pulls back the veil on the small black microchip and shows the inner workings. The "Three Fives" Discrete 555 Timer kit took about an hour and is very easy to assemble.    

Assembled
Components
Completed PCB
Wired for testing.


Circuit used for testing (Flashing LED).





Monday, July 14, 2014

Elenco's Surface Mount Technology Kit Model SM-200K

The SM-200K kit is to help one get familiar with working with Surface Mount Technology. The SM-200K Decision Maker will answer any question the user asks. When the asked button is pressed, six LEDs are driven on and off; in addition, a buzzer will sound. After a few seconds one LED will remain lite answering ones question. Over a few minutes this LED will dim and then go out. The Theory of operation of the SM-200K is six LEDs are driven by a decimal counter and two oscillators. The decimal counter is driven by one oscillator and the buzzer is driven by the other oscillator. 

Completed
PCB
Tinning for Resistor Mounting.
Mounted Resistors.
All components mounted.


Sunday, June 29, 2014

SMD Happy Face by Velleman

The SMD happy Face is a great kit to practice soldering Surface Mounted Devices (components are mounted onto the surface of printed circuit board).  I soldered these components by tinning one pad with solder, with tweezers applying the component and reheating the solder to mount, lastly, soldering the other pad(s) to connect the component to the PCB. As one can see in the first picture SMD can be very small. The 2 Transistor and 2 LEDs are size SOT-23 (2.9 mm x 1.3 mm/1.75 mm x 1.3 mm). The 4 Resistor are size 2012 (2.0 mm x 1.25 mm). The 2 Capacitor are size 3225 (3.2 mm x 2.5 mm). These components create a Astable Multivibrator Circuit or Oscillator producing a square wave. This makes the LEDs blink on and off. Below the video are a few links that I used as reference and for more information about this fun technology.

Top to bottom Resistor, Capacitor, LED, and Transistor.
One side of the resistor soldered.
Tinned Resistor pad.
Tinning Transistor pads.
Assembled Happy Face.

Friday, June 27, 2014

Bulb Dial Clock by Evil Mad Scientist

The Bulbdial Clock kit was developed by Evil Mad Scientist based on a design concept by David Friedman. The Bulbdial Clock uses 72 LEDs to cast 3 shadows (hours, minutes, seconds) for telling time (indoor sun dial). This kit includes a pre-programmed ATmega328p microcontroller, 20 ppm quartz crystal, power supply, resistors, capacitors, gnomon spike, and mounting hardware. The 72 LEDs are driven using Charlieplexing. In addition to the Bulbdial Clock kit, I purchased a Chronodot to provide battery backup to the clock. The Chronodot is pre-assembled and easily fits into sockets on the Bulbdial blue PCB. This was a fun and simple DIY kit to assemble and the folks at Evil Mad Scientist provide very detail instructions. Below my pictures I will display more links for reference. This clock looks wonderful above my fireplace.

This PCB contains the bulk of components including a ATmega328p microcontroller.

Blue LEDs added to PCB for minute hand and Clock face with Gnomon spike.
Adjusting the LEDs for a Gnomon shadow for second hand. 
LEDs in green Circuit Board before soldering for the minute hand. 
Unmounted red Circuit Board. 
Mounted Red Circuit Board
Adjustment of the hour hand.
Chronodot.
Black case.
Clear case. 



Tuesday, January 7, 2014

Motion Detector Kit Model AK-510 by Elenco

The AK-510 is an Infrared Motion Detector. The Infrared Detector detects heat radiation. This detector can detect up to 10' away but Elenco recommends detection at 6'. The AK-510 circuit is made up of Amplifier, High and Low Filters. Sound Generator, Power Supply, and Infrared Detector.

Completed AK-510
  

Friday, January 3, 2014

Work Bench 2014

This is my Work Bench at the start of the new year. I am hoping in this new year to explore microprocessor design and programming; in addition, one or two robots based on Parallax and Arduino themed microprocessor. If I have time and money, I want to explore DIY mini-computers like Raspberry Pi or Beagle Bone. I hope this will be a great year of my viewers, my friends, my family, and my blog.