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.

Tuesday, December 22, 2015

PCB from China 3

Just got in the new blimp boards for work. From http://dirtypcbs.com/ . Turned out great really impressed

Heres some pics

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Hole Size
Trace Size

Tuesday, December 1, 2015

Camper fan speed control

During our last camping trip we really need to control the exhaust fan over the stove,  it was really cold out and the fan was a bit to strong. So I came up with a couple ideas:

1. Use a resistors to drop the speed. The problem with this is the power loss. Don't forget were on batteries and do no wish to dump energy as heat.

2. PWM - this would be the most efficient use of power and would not required expensive components.

Here is the schematic:

Used vero-board for this project since it was so small

Frequency of PWM is out of the range of hearing so it's quiet, I originally tried 1khz PWM frequency on the breadboard but it made the motor sound like a screeching cat. So I made C1 smaller until i could no hear the PWM.