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 you duff and build something!
Training the hand and mind since 1982.

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."

Sunday, March 13, 2011

PCB design Old School Style

Hello everyone. I'm back after a couple of weeks having a bad cold. Arrg it's the season, everyone is sick. Well this weeks video is on PCB design Old School Style. Yep Just paper pencil and some sharpie and you too can make PCB at home or at work. It's kind of a dying art, designing it by hand without the aid of computer design software. When was a boy we didn't have computers so all of our design work was paper and pen, I still occasionally do this method for simple single layer deisgns. There is just something about connecting with your design, actually touching it and creating with your hands. With my current designs I don't even touch anything until the PCB is done and out of the milling machine and even then I just move it to a pick and place machine. Boy times have changed. Here are the Vid's enjoy.

Here are the still images on the PCB, I didn't mention that the second time around drawing on the PCB with the sharpie I use the template (just the holes not the body) to neaten things up.

Monday, March 7, 2011

A Blast From the Past - The ELT Detector

I was going though some of my old files and came across my Senior Project for my Bachelors Degree back in 2000. Basically we had to design, build and prove a working electronic project of our choice in order to graduate. Well being a ham and in the Civil Air Patrol my choice was to make something in RF and help the CAP. The design I came up with was a pager size device that would alert a pilot there ELT or Emergency Location Transmitter was on. A lot of time when we got called out to search for these ELT's they were false alarms in fact over 59 out of 60 of my documented finds were false activations. I wanted to design a product that a pilot could wear or throw in his fight bag that if there was a signal on 121.500 Mhz (121.775 prototype) and was less than 200 feet away it would beep.

I could remember so many hurdles in fact one of my professor strongly recommended not do a RF project because of all the unsuccessfully attempts by other student in the past. But 10 weeks later I had a working prototype that was close to be manufactured. Had a lot of fun and it was a ton of work but learned alot and it was my first RF design and the first use of SMT.

A second unpublished off shoot of this was to prove a cheap way to monitor all airports as a base station application and link via telephone/cell lines. So the signal could be located almost instantly near airports or base stations and dial to the Air Force Rescue Coordination Center. Kind of similar idea of the the home ADT security systems, but for planes.

Here are some photos

You can follow this link ELT PROJECT to all the documentation of the project including PCB layout, how it works, and parts suppliers.

Soon to come, I still have the prototype and soon will shoot a video of it working I still have a practice beacon to test it with.

Here is an article in the local paper
The ELT Detector:

Chris Johnson decided to couple his interest in the Civil Air Patrol to develop a product that would reduce false ELT and EPIRB responses. An Emergency Locator Transmitter (ELT) for aircraft and the Emergency Position Indicating Radio Beacon (EPIRB) for mariners is a device found in most airplanes and boats. The purpose of these devices is to help track down planes or boats in distress either from crashing or sinking. The problem is that 95% of these "emergencies" are false alarms and it cost millions of dollars each year because every alarm has to be tracked down and investigated. In addition the false emergency could very easily mask a real emergency.

The solution to this problem is Chris’s invention, a small portable ELT/EPIRB monitor about the size of a pager. The device has a limited range so that it will only pick up a signal within about 100 feet. The pilot of a plane would wear the device clipped to their belt. If there is a hard landing that would falsely trigger the ELT, the pilot would know it and notify authorities that it is a false alarm thus averting a search and rescue operation. The device would work similarly for boat operator with an EPIRB.

Chris is currently completing his last quarter at NEIT and will have many job opportunities as well as marketing of his new product. As can be seen from the picture below, Chris did a high quality job and has this product in a very near manufacturing design layout. He made the printed circuit and successfully soldered very tiny surface mount electronic components.

Vin Scotto, Chair, and faculty of the EET department, are very proud of what these two outstanding students have accomplished. Barry and Chris are excellent ambassadors of the Electronics Engineering Technology program and have bright futures ahead of them. It is a prime example of what someone can do when they combine learned skill with a strong interest. It not only works out well for Senior Projects, but for an entire career. Vin always tells his students the importance of pursuing a career in an area of strong interest because you will be doing that job 8 hours a day, 5 days a week, and about 50 weeks a year for a 30 to 40 year career. If you are going to do that job for that long and want to excel at it, you have to have a passion for it. The result will be a very stimulating and satisfying career filled with opportunity and the pay-off is that you are having fun at the same time. Find out what excites you, develop skill in it and have fun applying that skill.