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Our first lab run of the solar water pump using a helical impeller (like the ones used on an oil wells) and a PWM (Pulse Width Modulation) 3 phase DC motor that is optimized for solar use (shifting the PWM frequency depending on voltage coming from the array…which tends to changes throughout the day). What does this all mean? Well we never hit our target efficiency (92%) or even exceeded the efficiency of traditional water pump (80%), instead we peaked at 53.4%. Dismal results on the first try, but it is the first try. Now its time to fish out the problems…motor, pump, controller, PWM frequency, test rigs and more. Sure wish I had that Finite Element Analysis software right now!
Power outlet right next to the rightmost vending machine in the Gate 9/10/11 area, and under the phone booth. Very few outlets available in PWM, apart from the business center which isn't open early in the morning. No wifi available.
Gracias a todos por vuestros comentarios y reconocimientos...
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Testing the PWM power-up circuit. It uses a MAX1724 to generate 5 volts from a lower voltage, in this case from the 3.7 volt battery. This is useful because things like the BlinkM and other external devices prefer 5 volts rather than the 3.3 volts that other useful things prefer (like the real-time clock there on the right, or the digital accelerometer there on the upper left, or the 2-channel capacitive touch sensor on the botton left.)
Gracias a todos por vuestros comentarios y reconocimientos...
Por favor, no use esta imagen en los sitios web, blogs u otros medios de comunicación sin mi permiso explícito - Todos los derechos reservados ©.
Please don't use this image on websites, blogs or other media without my explicit permission - All Rights Reserved ©.
It's got 16 5chip 1/2 LEDs. Most of them are cool-white now. Initially it had 50%/50% cool/warm-white, but the warm-white ones have died prematurely - for unknown reason.
This one still uses an ATtiny2313 as the brain, but I think I'll switch to a Mega48/88 later. It's got a real SPI unit, which can send out the data much quicker than the 2313's USI unit. This is crucial, as the PWM interrupt must finish very quickly for proper performance.
Air Force One Touches down at Portland International Jetport in Maine. I-295 in the foreground, shot taken at Mercy Pond in Portland.