Monday, December 30, 2013

Gathering with fellow pilots and Multicopter improvements

Most of the time I have been a lone rider in this hobby, having started from scratch on my own, since the traditional helicopters back in 2009. I would occasionally go to local air fields and try to mix in with seasoned RC airplane and helicopter pilots. But the environment would not always be too friendly, with the fixed wing guys not enjoying much the flying grass cutters.

Sunday, October 13, 2013

Going higher with the flyer

After very conservative steps with this model aviation hobby, I decided to get closer to the trends, and do some updates/improvements on my quadcopter while still being careful with the budget.

Tuesday, August 13, 2013

Powerwheels RC conversion

I soon noticed my 20 month daughter affinity to vehicles. I wanted to give her one where she could sit and enjoy the ride, but currently most powered vehicles for infants require they are able to reach the throttle pedal and properly handle the steering wheel. So I figured out the best way would be to go remote controlled. As I already had done previous projects involving RC gear, it would be piece of cake to turn a regular electric car into a large scale RC car where a small kid could sit inside.

Thursday, May 2, 2013

Power Supply Refactoring - finishing the details

In spite of already being a working device, there were aspects that like I explained in the previous post, required some attention. One of the major fixes was the voltage drift. This was caused by the 5 K potentiometer used to set the voltage end point. It was too large (the sweet spot of my setup was around 500 Ohms), which besides making it difficult to adjust, caused temperature induced resistance drift to be too large, causing an increase of around 200 mV from the initial voltage once the temperature settled.

Sunday, April 28, 2013

Power Supply Refactoring - closing the hood

After many hours of work I finally can say it's done. Even though I don't consider it the perfect work, I can definitively consider it a major improvement in respect to the previous version of the PSU:


Tuesday, April 16, 2013

Power Supply Refactoring - part 5

Prior to assembling the definitive power supply circuit board (i.e. the main electronics featuring the LM723) I took the time to set it up on a breadboard. Before that I finished the board containing only the large components such as the filter capacitors and the high wattage resistors (current shunt used by the regulator chip to sense the current across the power rail, and a bleed resistor for the output capacitor):

Sunday, April 7, 2013

Power Supply Refactoring - part 4

Another weekend have passed, and along with it a few more results as I slowly but steadily walk towards completion of the project. The digital voltmeter/ammeter displays have still not arrived from China. This is the last piece of hardware missing. Adding time to the equation and all the elements necessary to complete the project are available.

Friday, April 5, 2013

Power Supply Refactoring - part 3

Bit by bit the work is advancing. I have finally defined the schematic diagram from the entire power supply circuit. It includes also the PIC based fan control.

Monday, April 1, 2013

Power Supply Refactoring - part 2

The parts from Mouser have arrived (was pretty quick..wouldn't the shipment have been taken care of by FedEx):

Friday, March 29, 2013

Power Suppy Refactoring

In this previous post I had the chance to present and tear down my old custom-made power supply. It worked flawlessly for about 10 years. I decided to buy a new linear lab power supply because I needed something better with more features such as constant current operation and digital display of both voltage and current.

Thursday, March 7, 2013

NOAA APT Satellite - Night time weather pictures!

My first and accidental attempt at receiving images from a weather satellite was surprisingly very succesful. However as I only started capturing the RF signal late in the satellite pass, it was only possible to retrieve a small portion of the transmitted image.

Sunday, March 3, 2013

Receiving weather satellite images with cheap hardware

Before the Internet, anyone willing to independently obtain satellite imagery from the source would need to buy expensive equipment capable of decoding the analog slow scan video images transmitted by weather satellites  such as the NOAA APT ones. Today there are four of these NOAA satellites still operational, the NOAA-18, 17, 15 and 19. All of these are sun-synchronous satellites, which means these orbit the earth at around 800 Km of altitude and cross every latitude at approximately the same mean local solar time for each pass. This kind of orbit is useful because of the consistent illumination (by the sun) of the target upon each pass.

Monday, February 11, 2013

AMIRO - Autonomous MIni ROver

In a recent past I have been very active blogging about this project, which have occupied a portion of my free time in a rather pleasurable manner. After a period of pause I thought of bringing this project back to life, but not without providing an overview of what have been done.

Sunday, January 20, 2013

Teardown of one of my first electronics projects: a PSU

This have been for about ten years a loyal companion in my electronics projects. And greater than that the fact that it was itself one of my first projects. After that time it still works like a charm.However I thought it was time to replace it with a PSU providing more functionality such as constant current and digital displays.

Tuesday, January 8, 2013