Welcome to the N1IR Electronics Website. Totally off the cuff, one take, unrehearsed video projects for anyone interested in amateur radio, electronic design, makers, hardware hackers and science.

Get off your duff and build something!
Training the hand and mind since 1982.

Wednesday, November 30, 2011

Eyes, Ears, Brain Circuit

One of my students Alex D. came to me with a circuit design for the "Eyes, Ears, Brain". This is an exercise that uses different hemispheres in the brain. (I'll will post a link later).

We were approached by an outside party to construct 30 of these boxes with circuits. while Alex did a few prototypes we had to come up with a method of mass production to cut down from a couple of hours of assembly down to less than 10 minutes. The first step was to make a template for the top of the box ass seen below.

Thanks to PMT for the aluminum and a #6 tap. This was the template we machine out, the two #6 screws hold the plastic top of the jiffy box. This sped our machine from a few minuite to a matter of seconds. see below

Once we had a solid template we could design a PCB that fit on top of the switches and solder in the LED's. The original prototype was point to point wiring that was very labor intesive. The new PCB could speed up assembly.

Here is a pic of a partially assembled project, we used 1/4 inch holes for all the LED and switches. If you notice the slices in the PCB, this was for the switch tabs. The tabare to big for the drill bit we have in stock (.04") so we elongated the holes with the cutout bit (.0625"). The slits in the middle of the board are from the battery clip strain relief.

Once the first one was done we did some revisions and I haded the PCB milling off to a very good student of mine Zach R. who has a great talent on running out milling machine. Below are a half dozen assembled.

Finished and working

If anyone would like the gerber files and schematic please email me, this is an open source hardware project. Input to the design is greatly appreciated.

(1) PCB
(3) Green LED
(3) Switches
(3) 1/4 Watt Resistors
(3) LED holders
(1) 9V Batt Clip
(1) Solder 60/40

Alex D. - Principal contact for customer, Prototyping, Assembly Team
Zack R - Machinist for the PCB Mill, Assembly Team
N1IR - PCB designer, Template Design, Parts Procurement, Assembly Team

Tuesday, November 22, 2011

Open House Give Away

Hi All,
During open house last year came up with the idea of handing something out that was promotional to our shop. It had to be something education to electronics, of course cheap,easy to manufacture and require no soldering iron to the end user. I came up with this solution:

I used Traxmaker 2000 Pro (yes I know it old but it works really well and works in WINE) and one of our T-Tech 5000 milling machines. If you would like the gerber files email me. With all three milling machines running we can produce about 300 boards an hour.

I used machined IC pins and solder them in so all that was required to the end user is to plug in the components. Included would be the PCB with pins soldered, 1K 1/4 Watt resistor bent and cut, LED cut and 9V battery clip that was already pre-tinned from the factory, instructions and a small plastic bag.

You could expand this idea into many thing like a larger resistor to show different brightness of LED verses current, Bi Color LED's, small buzzer, etc.

BOM Break down
PCB $.02 (.5"X .65" can fit approx 256 on a 8X10 board)
LED $.035 (in qty of 1000)
Batt Clip $.18 (in qty of 100)
1k Ohm $.00741 (in qty of 5000)
IC Pins $.15 (really free from donation)

Total cost $.40 Each

I could probably get cheaper parts on E-Bay but my school only allows Net30 only so were kind of limited on were we can get parts.

Friday, October 28, 2011

Greeting all,

For this blog I'm reviewing the Spark Fun Electronics Bench Top Power Supply. Overall this a a great kit for the beginner in electronics or robotics, it breaks out your common voltages of 3.3V, 5V, 12V and -12V Let start off with the classic hits:

High quality PCB easy to solder.
Reuse of box as enclosure
24 pin ATX connector (Digikey P/N WM21362-ND). newer ATX supplies!
Standoff and hardware, nice touch
Fused outputs
LED power indicator

Now for the Misses:

Where is the wire to connect the binding posts? None included?
Okay quality binding post, not the worst I've seen but okay.
Could use a picture of fuse clip orientation, it was confusing to my students.
Need to move pads over a bit for binding post wire connection, they are very close to nut and could short to ground (this happened to one of my students)

Items I changed from the original.

no points taken for these items but may want to consider for next design.

Used different colors for different voltages.
Fuse in a weird position (moved fuses to under side of board)

Newer design

Stay tuned.....in the next few weeks when I redesign this and add some other features such as an adjustable plus and minis voltage using the LM317 and LM337. Also a redesign for a single sided PCB, this will make it easier for use to make with our T-Tech Milling machine.

Wednesday, October 26, 2011


Greeting All
Here is a handy little project I designed and built. It's a spin off of the classic LM555 CW Oscillator. But wait N1IR!.....isn't that a AA battery in the circuit? Why yes! the LM555 minimum voltage is 4.5 Volts so I design this circuit with a TLC551 LinCMOS, this is a direct replacement of the LM555 but can operate as low as 1 Volt! I chose this IC because the AA battery is less expensive and will last longer than a 9V and smaller foot print.

What's with pin 3 connected directly to the base of the TLC551? I thought you needed current limitation of the transistors? Yes and no.....with the supply voltage so low and current limitation of the IC (1mA) you can get away with it, thus reducing parts count.....but if you want a higher voltage let's say 3 volts or more you will need a current limit resistor from pin3 to the base's.

How do I change the battery? Well this is a prototype that was originally designed for one use disposal for a CW training class, the battery life is past 200 hours continuous use at 50% duty, far exceeding the class time. If you would like an easier battery replacement Radio Shack sells a AA battery holder you can solder in place of the current battery. Full production model may have a battery holder pending price.

What connector is that connected to your key? I used a SIP connector I salvaged off a computer case, this again was to make this as inexpensive as I could.

How about a BOM?

Will you sell me one for $5.74? NO!.....how about $10.00? NO!....How about $20.......NO! If you would like one please sign up for our upcoming CW class course at the Genesis Amateur Radio Club, they are a donation for students for our class only.

Tuesday, October 11, 2011


Thanks Chris (my brother in law) for giving me his old NES system version 2. I had one years ago and missed it. I use to have a version 1 and sold it at a yard sale when I was a kid in the 90's and regretted it ever since. Now with all the info on the web I was able to do a couple of modifications, something I couldn't do or had no knowledge of all those years ago.

Mod 1 Lock out chip disable

This mod I did because of the 1 Hz flashing problem with some legit games here are some pics, the lock out was always a pain and caused lots of problems with start up.

Mod 2 Blue LED, give the old system a new look

The Led is tied to +5V on the anode and has a 220 ohm (R5) connected to a 74HCU04AP, I looked up the data sheet on the "04" and the output can sink or source up to 20mA not a problem with the blue led (10mA) with some calculation I figured about 8mA was flow through the LED, fine for me it's still very bright and give a modern look.

Tuesday, September 27, 2011

Generator Project

Hi bloggers, sorry I havent posted in a while I've been working on a new project with a gasoline generator, after problems with the power and NStar, decided to get a used back up generator. As an added bonus I can go boon docking at my local state forest. got the genset for about half retail, just needed so elbow gresse a new spark plug, stop valve, and some misc. hardware. I also restorde the quick connect gas tank a nice feature with this generator, video posted below

Here is the link for the panel back-feed safety lock http://www.nooutage.com/interlock_squared.htm

Genesis ARS to Sponsor General Classes at Jordan Hospital of Plymouth

The Genesis Amateur Radio Society, in cooperation with Jordan Hospital will conduct a General license class culminating in a volunteer exam testing session in November, 2011. The class sessions will be held at Jordan Hospital:

Friday, November 11, 2011 6:30-9:30 PM - Boynton Room
Saturday, November 12, 2011 9:30-6:30 PM - Scarzi Room
Sunday, November 26, 2011 9 AM-6 PM - Funkhouser Room B

The third class date includes a test session from 3-6 PM. Walk-ins for the exams ONLY are allowed from 3-3:30 PM.

While not mandatory, it is recommended that candidates participate in all three classes. Registration is required due to limited seating (10).

To register, visit www.genesisars.org and email the completed registration form to education.registration@genesisars.org.

Class participants must have a copy of the ARRL General Q&A Manual and, optionally, the ARRL General License Manual. A fee of $15.00 is required for the ARRL VEC-sponsored examination.

For questions, including obtaining the course material, please email: Joe Reynolds at ka1gdq at gmail dot com or call 508.296.3622 (voice mail) or 774.222.2542 (mobile); Chris Johnson, n1ir at arrl dot net.

We are looking for volunteers to assist in the instruction of the class and VE’s to. If you are interested, please contact Chris Johnson, N1IR, Genesis ARS Education Officer.

Sunday, September 11, 2011

maker faire

Ever wonder what is the maker faire? What is this Arduino thing I keep hearing about? What does autism have in common with science fair? Listen to this MP3 clip taken from “Off the hook with Emanuel Goldstein” WBAI New York September 7, 2011 99.5 FM you can download the full episode at 2600.com

Friday, September 2, 2011


Well I'm back after 4 days with out power. Below is a video of my set-up during Irene and power loss aftermath. In this post I will visit lessons learned and what to do next time here at home.

The emergency plan set-up HITS:

* Jayco 213 Trailer Camper, our life boat. Propane fired hot water, fridge, furnace and range/oven (manual pilot)

* After losing power power I transferred all the food to our camper fridge that is propane fired. However with no generator we lost all the food in our deep freezer after the third day.

* (2) 80 Amp hour battery, ran all the radios, auto-patch for the EOC's for (2) days with out recharge. Had 20M,10M,2M,440CM and scanner radio working.

* Filled fresh water 32 gallon tank two days before storm, water lasted (4) people two day before refilling, in case town water shut off or bad water.

* Auxiliary Anderson power Pole port in Honda Civic Trunk, this provided a way to charge/run Batteries

* Inverter 350 Watt and 140 Watt, Inverter ran TV/DVD and cable telephone PBX / Internet modem

* 10 gallons of gas on hand, power was out for days and the fuel pumps where not working

* Plenty of 9V,AA,AAA,C and D Batteries and flash lights

* Tons of food and water

* 600 Lbs of propane plus (4) 20Lbs Tanks, look into a way to connect trailer into big tank.

The emergency plan set-up MISSES:

* No hotwater in main house (electric water heater), However had hot water in camper, Look into propane hot water heater upon upcoming replacement.

* Generator to run at least the house lights and or deep freezer and or furnace during winter.

* Fast battery charger, when charging from the car the voltage wasn't high enough to quick charge the lead acid (14.4V) look into inverter / 20 amp battery charger combo

* A way to pull up the car closer to the radio shack, currently using 50 foot 12AWG extension cord for 12 volts some serious loss!

* printer that works on USB and smaller power than my laser printer, had to print out a couple of things but the laser printer took too much power

* Cordless phones need power! Look into corded ones and swap them in during storm.

* bigger battery in cable phone PBX, ran ok with inverter but can hack a bigger battery in 4.8AH lasted two days, Also power up WIFI and cable modem.

* could not light oven, electric pilot (used camper oven)

Tuesday, August 23, 2011

Florescent Light Upgrade In The Lab

Hi All,
Decided to place a light above my lab work bench, after doing some research on what type of light LED, Florescent or halogen I came across Ben Krasnow site explaining the difference between T12, T5 and T8 bulbs and efficiency vs light output, see video below.

I already had a bad cheap T12 "shop light" with a bad ballast that burnt out a few months ago, I know I'm a pack rat. Bought a ballast and two t8 bulbs at Home Depot GE232 -120RES-DIY Stock number 71037 for $14.99 and two GE F32T8 SP41ECO 4100K around 5 bucks.

The wiring was a bit different than the old ballast, just follow the drawing on the new ballast, bi pin are the same.




Best of all there no annoying hum and it's very, very bright located about 24 inches from the bench surface. Double the light output at half the current of my old T12's! Great projects for a newbie!

Tuesday, August 9, 2011

Budget Crisis from an Engineers point of view

Hello all, I was discussing the current budget crisis with a friend of mine. A good point was brought up.....if anyone of us had a similar budget to run our homes we would be in serious trouble. Let me give you the numbers

Us Income__________2,170,000,000,000
Federal Budget_______3,820,000,000,000
New Debt___________1,650,000,000,000
National Debt_______14,271,000,000,000
Recent Budget Cut_______38,500,000,000

Okay kind of tough to wrap your mind with large numbers, let's use powers of ten and cut some zero (eight places) to make it more manageable.

N1IR Income__________21,700
N1IR Spent___________38,200
Credit Card New Debt____16,500
Balance on Credit Card___142,710
Cut Made by N1IR_________385

With simple powers of ten you can clearly see the problem, why can the people in washington see this? Food for thought....N1IR

Tuesday, August 2, 2011

Genesis ARS to Sponsor Tech Classes at Jordan Hospital of Plymouth

Submitted to K9HI by KA1GDQ on Sat, 07/23/2011 - 21:01 Posted on http://ema.arrl.org

The Genesis Amateur Radio Society, in cooperation with Jordan Hospital will conduct a Technician license class culminating in a volunteer exam testing session in August, 2011. The class sessions will be held at Jordan Hospital:

Friday, August 12, 2011 7-9 PM - Boynton Conference Room
Sunday, August 14, 2011 1-6 PM - Boynton Conference Room
Saturday, August 27, 2011 9 AM-5 PM - Funkhouser Room B

The third class date includes a test session from 2-5 PM. Walk-ins for the exams ONLY are allowed from 2-2:30 PM.

While not mandatory, it is recommended that candidates participate in all three classes. Registration is required due to limited seating.

To register, visit www.genesisars.org and email the completed registration form to education.registration@genesisars.org.

Class participants must have a copy of the ARRL Technician Q&A Manual and, optionally, the ARRL Technician License Manual. A fee of $15.00 is required for the ARRL VEC-sponsored examination.

For questions, including obtaining the course material, please email: Joe Reynolds at ka1gdq at gmail dot com or call 508.296.3622 (voice mail) or 774.222.2542 (mobile); Chris Johnson, n1ir at arrl dot net.

We are looking for volunteers to assist in the instruction of the class and VE’s to. If you are interested, please contact Chris Johnson, N1IR, Genesis ARS Education Officer.

Tuesday, July 26, 2011

10,000 LM324 Donated

Hi All,
In the shop we had over 10,000 LM324 Quad Opamps donated to us.Thank you MASSA Corp http://www.massa.com/.

Now what the h3ll do we do with 10,000 LM324. The only answer?? Design kits for exploratory students! In our school we have a program that during the first year of 9th grade each student get to tryout 8 shops for the first half of the year, then they get placed in the trade they whant to study for the next 3.5 years. It's a huge expense for our shop we see anywhere from 80 to 100 students in 45 shop days. Yes 45 full 6 hour days, we can use a lot of parts! Project need to be design as easy beginner projects and we have order PCB from china at about 50 cents each so total cost should be under 1 dollar each project.

First Idea: Insanity Alarm Kit Ver 1

Second Idea: LED Fade Effect Kit Ver 1

Third Idea: Blinking LED

Tuesday, July 19, 2011

SPARKFUN Clockit Kit Review

Hi Bloggers,

I recently purchased a Clockit kit from SparkFun Electronics to evaluate it for my students.

Overall this is a great kit for beginners there are a couple of really good hits and a couple of misses

The first and biggest miss is the DC power connector doesn't fit right! it's way off I mesured about 6.53mm O.D. a huge difference in size of the 5.5mm O.D. plug, producing a very sloppy connection (see video n1ir.com) and would cut power as soon as I move the PCB even the slightest.

I replaced the original jack with a Switchcraft 5.5mm X 2.5 mm Jack (RAPC712X). I have a solid connection now without problems, hopefully sparkfun will look into this and change the jack to the proper size.

The second miss but can easy be changed with programming is setting the time, there is allot of switch bounce (one press can register as 2 or more presses), It's annoying but I can live with it. With a simple subroutine for advanced users can fix this.

The third miss WTF? display is used ????? It's stamped YS on the side. After doing some research I crossed it over to a Lite-On (LTC-4627B) the crossed part has a grey face instead of the black that comes with the kit but still blue in color. Please add this info in web site.

Big Hit I really like the PWM of the display LED's that reduced the parts count. It's a very clever, a novel solution to reduce parts. Usually you see current limit resistors for each segment this would be 35 resistors in this design, by using PWM it eliminated the need and reduced the cost of the design, excellent idea!

Big Hit Bright flash when going into set mode, to set the time. Three flashes to know it's been accepted.

Big Hit ICSP Header, can be reprogrammed in circuit as a timer or modified. Wish they had some more example code on the kit web site.

Big Hit comes with a power supply, usually kits don't included this, A++.

WISH LIST Would love to see:

24 Hour Mode (software solution, press up, down, snooze same time for 10 seconds)

Brightness control (software solution, press up 5 times, high, med, low, and off)

SIP connector PCB pads for +/- supply for battery backup (hardware solution, optional NI-CD cell/ super-cap in paralleled with supply) just for a few minutes of backup for any surges or power outage. Possible sleep mode while in backup (hard to do without a redesign....need an open port and support circuitry)

Thursday, July 14, 2011

Pneumatic Antenna Launcher

Hello all again, here is a project I did some time ago. A Pneumatic Antenna Launcher, a bit of CAUTION! treat this like a firearm, you can recived major injury if not used properly. SAFETY FIRST!

On to the videos, a list of parts are located at the bottom of this form.

Parts List
3" End Cap
3" PVC pipe (12"Long)
3" to 2" Adaptor
2" to 1.5" Adaptor
1.5" to 1.25 " Adaptor
1.25" to 1" Adaptor
1" PVC pipe (two of them 2" Long)
1" Threaded to 1" Pipe Adaptor (two of them)
Sprinkler Valve 1" Threaded
Metal Schrader Valve (auto store)
1"to 1.25 Adaptor
1.25" coupler
1.25" Pipe (24" Long)

Batteries (24V)
Switch Toggle (safety)
Switch Push Button (fire)

LM555 One Shot trigger (3 Second pulse)

UPDATE: here are some shots of the finished version

Wednesday, June 29, 2011

The red and black little bug looking things

Hello all, below are a couple of video I shot using some Anderson Power Pole connectors and cigarette plug adaptor. Good project for a rainy afternoon. You can buy one of these adaptors commercial already built cost around $10.00 USD, but I will show you how to make your own from under $3.00 USD

Here is a parts and price break down

From www.mcmelectronics.com
MCM 27-110 Lighter Plug $0.60
MCM 24-1900 14 AWG Wire $0.22 (for 6 inches)
MCM 21-3300 Powerpole Modular Connector $1.69 (One Set)
MCM 108-2405 1/4 Inch I.D. Black Heat Shink Tubing $0.10 (for 2 Inches)


MCM 22-770 Heavy Duty Crimp Tool For Solder-less Connectors $20.00
powerwerx.com TRIcrimp $39.99

Tuesday, June 28, 2011

Field Day 2011

Field Day at the Genesis Amateur Radio Society, located in Plymouth MA

what is this field day thing anyway

Field Day is an annual amateur radio exercise, widely sponsored by IARU regions and member organizations, encouraging emergency communications preparedness among amateur radio operators. In the United States, it is typically the largest single emergency preparedness exercise in the country, with over 30,000 operators participating each year.

Since the first ARRL Field Day in 1933, radio amateurs throughout North America have practiced the rapid deployment of radio communications equipment in environments ranging from operations under tents in remote areas to operations inside Emergency Operations Centers (EOCs). Operations using emergency and alternative power sources are highly encouraged, since electricity and other public infrastructures are often among the first to fail during a natural disaster or severe weather.

To determine the effectiveness of the exercise and of each participant's operations, there is an integrated contesting component, and many clubs also engage in concurrent leisure activities (camping out, cookouts, etc.). Operations typically last a continuous twenty-four hours, requiring scheduled relief operators to keep stations on the air. Additional contest points are awarded for experimenting with unusual modes, making contacts via satellite, and involving youth in the activity.

Saturday, June 4, 2011

Video Edit Test

Hi All,
Just me soldering on a 3.5mm plug, just testing a video editing software called Pitivi for Ubuntu, looks like it work really well. Just upgraded to 2GB of RAM...helps too. Enjoy.

Tuesday, May 24, 2011


Hi All,
I haven't done a video in a while, here is a review of the Astron Linear Power supply 20 Amp @ 13.6Volts. This supply in the video I bought about 20 years ago at a HAM radio flea market and just recently dropped it by accident six feet onto a concrete floor...oops. Will it work??? see what happened in the video. Tear down time!

Wednesday, May 18, 2011

OCCED7000 is DONE!!

Finally back after a couple months of course work for a masters degree, thanks Professor Alicata great course, hope to have you again in another course.

Well anyway back into electronics here is a project I think is number one piece of equipment you should build a Triple Power Supply bench top laboratory grade supply. There are plenty of kits out there for the beginner, if your more advanced you can build your own from scratch. I would recommend LINEAR 5 Volt at a couple of amps and dual +/- 15 Volt at about 1 or 2 amps at most. This will cover about 99% of the items you breadboard up and test. Below are some pictures


25 turn potentiometers, to get in fine voltages

Heat sink are part of copper substrate (about 2 sq inches under chip)

Added AL heat-sink (not pictured)

PM128-E meter, enhanced pm128 with common ground feature so I can tap off the 5 volts to power
the LCD display instead of using a 9 volt battery like in the regular pm-128's

+/- 0-15 Volts (LM317,LM337) and fixed 5V (LM7805)

Two big filter caps 1500uF at 100 Volt

four heavy 6 amp rectifier diodes (way more than I need)

This is an old version a current version we are going to use next school year is an arduino based display, our old display PM-128E cost about $20 and only displays one voltage at a time. With and arduino based screen we will have 20X4 Blue LCD display all three voltages at the same time and all three current outputs and at less cost about $5 to $10. The display first displays a splash screen with the student name and year of grad and email for 10 second on start up then displays this:

SSVT TPS Model 101

Tuesday, May 17, 2011

Field Trip 5/13/11

Field trip to of Museum of Science, kind of bummed out that they took down the display of the apllo memory modules and old computer stuff 8080, 286, 386, oh well change of the times I guess. But we did see the world largest Van de Graph generators video below. I can always remember when they first opened in 1980 my dad took me and I was amazed. This generator was built to study light ion direct nuclear reactions, atom-smashing, high energy X-ray and atomic acceleration experiments, this was before the atomic bomb an done back in the 1930's pretty impressive. This generator can often reach 2 Million Volts, again pretty impressive in 1930's. http://www.mos.org/sln/toe/construction.html

Sunday, May 8, 2011

Work Bench

Here is a shot of my work bench in at work, this is at the end of the week when it get kind of messy. A controlled chaos :)

Current to Voltage Converter

I designed this for our Arduino based triple power supply. The supply is a bench top linear supply with a 20X4 LCD screen. Displayed on the screen is voltage V1,V2 and V3. Easy enough to monitor with the Arduino A/D converter with a basic voltage divider. However to monitor current we needed a current to voltage monitor, I searched the web and found some current to voltage monitors but there were not cheap, cost was around 30 bucks. My design this cost around $5 USD.

The heart of this circuit is the LMP8603 a 60V Common Mode, 100 x Gain Bidirectional Precision Current Sensing Amplifier
. With a very small value resistor to get around the burden voltage. I used a .01 ohm resistor that could measure 0 to 5 amps at 0 to 50mV across the resistor then added the LMP8603 with a gain of 100 so for every amp I would get 1 volt out.

The great thing about this IC, it's bi directional, it can be a high side or a low side configuration. It uses a single supply, A set gain of a hundred with no precision resistor needed like standard op amps.

Resolution of this is around 5V(A) / 1024 (10bit A/D) = 4.8 mA per step, if you need to change the resolution you could always swap out the resistor with a .1 Ohm but you maximum current would only be .5 amps, but resolution would increase to .48 mA per step. For my case I chose the .01 ohm.

Wednesday, May 4, 2011

Work Pics Continued - 3D Printer

Here is me in front of our Stratasys - Dimension 3D Printers, Rapid Prototyping System
This printer prints 3D dimensional object that is created by laying down successive layers deposited as fine as 0.007-inch of material in ABS plastic. Once design in CAD then is converted in to a stereolithography file (STL) then printed just like you would a normal paper printer, that it really that easy to use. The 3d printer is also Ethernet network capable, just set you IP and share it with you coworkers.

3D Printer Video

Tuesday, April 26, 2011

My milling machine at work

T-Tech QC 5000 milling machine, PCB fabrication. This is one of my favourite equipment, wish I could get one for home but at $5,000 it doesn't look like I can get one for myself. What use to take me two to three days with a chemical etch-ant process I can do in 15 minutes with an environmentally safe mill. No chemicals! and the dust is collected by a HEFA vacuum system. At work we have 3 machines, 2 pneumatic Z Axis and on electric Z Axis. Machine #1 is over 10 years old and used everyday!

Here are some video's of the mill in action. This is from Texas Tech IEEE.

Breadboard Power Supply

Here is a great addition to you bread boarding tools, a breadboard power supply. This is a follow up on my video on how to breadboard.

This plugs directly into a standard breadboard and proved power on the rails on each side. Can be adjusted from 1.3V to 15V DC. This is a great first project, infact this is the first project our incoming 9th Grade students build.

Compact Linear Breadboard Power Supply

This project details the design of a adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs

* LM317 regulator has guaranteed 1.25A output
* 1.25V Dropout Voltage
* Short circuit and overheating protection
* Input diode to protect circuitry from negative voltages or AC power supplies.
* 2.1mm DC jack voltage inputs
* Two indicator LEDs for high and low voltages
* Onboard pot for adjusting voltage from 1.25V up 20V
* Heat sink

Today marks 50th anniversary of first silicon integrated circuit patent (and the entire computing industry)


By Zach Honig posted Apr 25th 2011 4:23PM

There's little question that the last 50 years have represented the most innovative half-century in human history, and today marks the anniversary of the invention that started it all: the silicon-based integrated circuit. Robert Noyce received the landmark US patent on April 25, 1961, going on to found Intel Corporation with Gordon E. Moore (of Moore's Law fame) in 1968. He wasn't the first to invent the integrated circuit -- the inventor of the pocket calculator Jack Kilby patented a similar technology on a germanium wafer for Texas Instruments a few months prior. Noyce's silicon version stuck, however, and is responsible for Moore's estimated $3.7 billion net worth, not to mention the success of the entire computing industry. Holding 16 other patents and credited as a mentor of Steve Jobs, Noyce was awarded the National Medal of Technology in 1987, and continued to shape the computing industry until his death in 1990. If Moore's Law continues to hold true, as we anticipate it will, we expect the next 50 years to be even more exciting than the last. Let's meet back here in 2061.

Thursday, April 7, 2011

555 Timer Easter Egg? - Over Easy!

This is my video response to the 555 Timer Easter Egg by Dave Jones over at the EEVBLOG. I'm not toally sure how Dave got his to oscillate but my circuit is not. I've tried all sorts, used battery power reduced the voltage down way below spec, used different scope/probes, changes chips, but still can't duplicate Dave's problem. I've also had my whole senior class breadboard this circuit and all ten of them where fine, no oscillation. I'm at a loss on how to duplicate this. Check out the video, I have some other ideas what it might be. If you want to see me build the circuit check out Video 7 "Breadboarding - Pass the Flour?

Chip Info
LM555CN National JR34AD
7555IN NXP 9E1K410 UnG946D
LM555CN Fairchild K233

Breadboarding - Pass the Flour?

Hi All,
This episode is all about breadboard, some tip and tricks about basic bread boarding, proto boarding, what ever you call it, for the entry level technician. This is a test circuit from Dave Jones EEVBlog 555 Timer Easter Egg video. A note: in the video I forgot to tie both side + and - rails together but you'll see that in video 8 and the 4.7 I mention for the resistor between 7 and 6 is really 1.472K. Again no editing one shot deal totally off the cuff.

Sunday, April 3, 2011

Video #6 TDA, RDF, WTF?

Hi I'm back, after being ill for a couple of weeks. Shout out to C Morgan my first follower.

Today we have my video on TDA Time Difference of Arrival Radio direction finding. A basic ciruit to turn your HT into a killer Fox hunting / ELT hunting piece of equipment. All you need is a few coat hangers, some coax, couple of diodes, resistors and caps and an audio square wave oscillator of your choice. There is an addition to the video I forgot to mention the inductor choke in the circuit, it to prevent R.F. getting into the audio oscillator circuit.

How it works:
Time Difference of Arrival RDF (DF) sets work by switching your receiver between two antennas at a rapid rate. When both antennas are the same distance from the transmitter, the RF phase received by both antennas will be identical, with the same impedance in both diodes. If the two antennas are different distances from the transmitter the RF will have a different phase at each antenna and one diode will conduct more than the other, like an analog OR gate. If we switch between the antennas 500-1000 times a second, this phase change will be detected by an FM receiver as a 500-1000 Hz tone. By turning the antennas for a null in the tone, your two antennas will be perpendicular to the transmitter. Additionally when a diode is conducting via switch and battery in forward biased mode the circuit operates in Yagi (Rec) mode and you can determine what general direction the signal is coming from. Eliminating the confusion between a front or rear signal of receiver signal that you would get in (DF) mode

Video 6 Part two, I go over what an ELT is and some basic RDF tricks.

Thursday, March 17, 2011

The CQD Experience, The Ignition Switch

This video is for "The Ignition Switch" featured in QST Aug09. This circuit provides protection against transient protection when starting your car and proves a delay off time for APRS equipment to send data before shut-down. Over all this project is about 3 out of ten for difficulty, all parts available though mouser or digikey. I'm still doing video's in a one shot deal no editing this one is a bit rough.

Some thing I have to test but haven't done yet is try the TLC551, it's another version of the 555 but even less current than the 7555. I'll keep you updated on that test.

This is from the article QST Aug09
"My goal was to come up with the smallest and least expensive circuit consisting of readily available parts. The heart of the circuit is a 12V relay rated at 25A. The circuit also consists of two 7555 IC's, CMOS version of the famous 555 timer developed in the early 1970's. Total current draw is about 100mA while on and 0mA while off. The first timer, U1 turns on by battery voltage from the vehicle ignition switch and turns on timer U2 via D2 after a 10 second delay. When U2 is turned on , it energises relay K1 via Q2. K1 keeps power on U2 until it's time cycle is completed and K1 released. Timer U2 is kept from timing and relaseingK1 by Q1 until battery voltage is removed from the vehicle ignition."