Thursday, May 28, 2015

California Nonprofit Offers Free Solar Panels to Its Poorest


California Nonprofit Offers Free Solar Panels to Its Poorest




Photo: Michael Macor, The Chronicle via SFGate Magazine



 
A new California program by the Oakland nonprofit Grid Alternatives will install home solar arrays in disadvantaged neighborhoods and aims to make solar power available to lower-income families — using money from the state’s fight against global warming. 

Full story by David R. Baker at SFGate Magazine:

  
  http://www.sfgate.com/business/article/Low-income-homeowners-get-free-solar-panels-6281762.php


Wind Turbines With No Blades


Wind Turbines With No Blades

A prototype of the Vortex Bladeless wind turbine from Wired Magazine 



"A Spanish company called Vortex Bladeless is proposing a radical new way to generate wind energy that will once again upend what you see outside your car window."

If you happen to see one of these, and are wondering what the heck it is....

Full story at:


http://www.wired.com/2015/05/future-wind-turbines-no-blades/



How To Build a Solar Cabin For Under $2000



How To Build a Solar Cabin For Under $2000


Nice video by Lamar Alexander, includes links to plans.

It is a 14' x 14' cabin with loft, providing about 400 square feet.
Power system is 580 watts Solar electric and 400 Watts wind power which powers a 12 volt fridge, lights, water pump, TV's, laptop and many gadgets. 
Heat source can be propane or wood stove. 
Toilet is solar assisted composting.




Wednesday, May 13, 2015

How to Build the SolN1 Portable Solar Generator for Safety



How to Build the SolN1 Portable Solar Generator for Safety

LaserSaber came up with the idea of a light-weight mobile solar power generator with his video on YouTube.


However, the original SolN1 is missing the controller, and that controller should be compatible with LiFePO4 batteries...

Also, if you use the flat LiFePO4 batteries, you really need a Protection Circuit Module (PCM) for charging the four (flat) LiFePO4 batteries.


Here's a video from John Strabismus where he has the LiFePO4 controller and PCM:



  
The charge controller is needed so that you do not overcharge the battery. If you overcharge the battery, the LiFePO4 batteries tend to swell up, and can emit some dangerous fumes. In the worst case, they can even catch fire.
 
The battery management system is required because combining batteries for total power can cause a discharge at different rates per battery. This can cause problems when charging, leaving some of the battery pack undercharged, and others overcharged.

Regarding sizing of the PCM module, John Strabismus says:
 


"The main thing to keep in mind with your PCM choice is the size of the inverter you will be running. LaserSaber chose a 150w inverter, fully loaded it will pull close to 15amps continuous and surge a bit higher, that's why the surge rating on the PCM is higher than needed, as the inverter starts up with load it will pull more amps briefly then settle to its load draw, so the 16amp PCM matches the 150watt inverter, if you go higher like a 200 watt inverter you will be over the 16amps draw fully loaded and this will more than likely cause the PCM to shut down the load , so using a 20amp PCM for a 200watt inverter will match the components better."

So, you should remember that the PCM chosen should be based upon the power of the inverter.

You can find the PCM circuit boards on BatterySpace.com:

------------------------------------  
  - PCM for a 150 Watt inverter:
------------------------------------  
Protection Circuit Module (PCM) for 4 cells (12.8V) LiFePO4 Battery Pack at 16A limited  
Part Number: PCM-LFP12.8V16A

http://www.batteryspace.com/pcmprotectioncircuitmodulefor4cells128vlifepo4batterypackat16alimited.aspx


-------------------------------   
PCM for a 200 Watt inverter:
-------------------------------
Protection Circuit Module (PCM) for 4 cells (12.8V) LiFePO4 Battery Pack at 20A limited
Part Number: PCB-LFP12V25A


http://www.batteryspace.com/PCB-for-4-cells-12.8V-LiFePO4-Battery-Pack-at-20A-limited.aspx


or


Part Number: PCB-LFP12.8V20A
http://www.batteryspace.com/pcbprotectioncircuitmodulefor4cells128vlifepo4batterypackat20alimited.aspx

   ------------------------------------------  

The "Flat" type of LiFePO4 batteries can be found on AliExpress:
 

3.2V 20Ah A123 LiFePO4 Prismatic APP72161227 PHEV/EV/E-REV Rechargeable Battery      $33.88 each x 4
http://www.aliexpress.com/w/wholesale-a123-prismatic-lifepo4-20ah.html

3.2V 5C   20Ah
Nominal Voltage:    1.2V
Nominal Capacity:    20Ah
Size:    7x166x227mm       (.276" x 6.54" x 8.94")
Package Size:    10cm x 10cm x 5cm (3.94in x 3.94in x 1.97in)
Cell Weight:    About 496 g   (1.09 pounds ea.)
Cell Capacity (minimum, Ah):    19.6A
Charge voltage:    3.75V
Power:    Over 2,400 W/kg and 4,500 W/L
Continuous discharge rate:    5C 100A
Peak discharge rate:    20C 400A (10 seconds) 



The original SolN1 videos:

 DIY Build Session SOLN1 Portable Solar Power:
https://www.youtube.com/watch?v=7CUuqJDzo1U

 SOLN1 - Amazing all in one free energy portable solar unit:
https://www.youtube.com/watch?feature=player_embedded&v=hy9wT7Vvkdw


DIY Build Session SOLN1 Portable Solar Power
https://www.youtube.com/watch?v=7CUuqJDzo1U

SOLN1 - Amazing all in one free energy portable solar unit.
https://www.youtube.com/watch?v=hy9wT7Vvkdw


Real Time SOLN1 Making-of + Other Updates
https://www.youtube.com/watch?v=x2XwmnjnwH0

SOLN1 Version 3 - Solar made easy!
https://www.youtube.com/watch?v=7-Y5TvWpWoQ


SOLN1 Update - Testing the Mini Boostpack
https://www.youtube.com/watch?v=z0a-2Zcy-VI


Battery Free Solar! Real Time Solar - Nano BoostPack + SOLN1
https://www.youtube.com/watch?v=_io9YHKdbTw
 

  
SOLN1 25 Kit Build Video - 20Ah Version
https://www.youtube.com/watch?v=MUUwnMwRlTk

Sunday, December 14, 2014

Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit (NC or NO??)

           Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit 

                                    (Normally Open or Normally Closed??)



I was looking for a simple temperature controlled cooling fan circuit for my prototype inverter, and was excited to run across one on YouTube from electronicsNmore called "Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit."

Great! Simple! 

Just like what I was looking for.

Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit from electronicNmore


So, I ordered some 45 degrees C (113 degrees Fahrenheit) bimetal temperature sensors that I found on Amazon "High Quality KSD9700 250V Bimetal 45 Celsius NC Temperature Control Switch Pack Of 10." 

The parts arrived promptly from China via U.S. Post Office, so I immediately set about getting the circuit up and running on a breadboard. 

However, it did not work! I was very puzzled - this is a very simple circuit to build.

I checked the video comments again. Sure enough, he said "Normally Closed" sensor.
  
  
Normally Closed sensor for Super Simple Temperature Activated Cooling Fan Circuit

  

So, I thought I would do a simple test to see if the sensor was really "NC" (Normally Closed), or perhaps the vendors sent "NO" (Normally Open) by mistake. A direct connect of positive to negative and directly to the fan should tell me. If the sensor is Normally Closed, then the fan should com on without the breadboard set up. 

The fan did not come on. It would appear that the vendor sent Normally Open temperature sensors instead of Normally Closed sensors! 

So, I had the wrong temperature sensors for this circuit. Let me see, my options were that I could send the sensors back to the vendor, but I got these fairly cheap, and the postage would just add to the cost. Or, I could look for a "NO" version of the YouTube circuit. I thought i would be easy.... wrong thought. 

I searched YouTube for a "Normally Open" version of the cooling fan circuit only to be disappointed. One blog said just buy the "NC" version if you have an "NC" circuit. Well, I already did that. How many times would this part problem happen?? So, I spent a few more hours on Google looking for a "Normally Open" version of this simple circuit without finding one.

After hours of searching, I was at a loss. I took electromagnetic theory in college, but other than that, I have no electronics training. So, writing up my own circuit is not something that I normally attempt. Then I remembered a comment from Mr. Swagatam Majumdar on his "Low Battery Indicator" circuit. You could reverse the polarity of the circuit in order to convert it to a "High (Overcharge) Indicator" circuit.



 
Converting a Low Battery Indicator into a High (Overcharge) Battery Indicator


Maybe I could turn the super simple temperature controlled (Normally Closed) circuit into a Normally Open circuit.

So, I gave it a shot. I reversed the positive and negative on the cooling fan circuit, changed the polarity of he transistors, and reversed the diode polarity.


And it worked!

Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit Normally Open

I am thrilled. Now I have a simple temperature controlled cooling fan circuit no matter if I have NC or NO type sensors. Excellent.

Ideally, if the circuit fails, you would want your cooling fan to be able to come on at start-up by default. That will be one of the things that I will test for. My guess is that the "Normally Open" sensor will not fail over when the sensor fails, but might fail over if I lose a transistor.

I have not checked yet, but you probably do not need a circuit for the "NO" sensor. I am thinking that it should work with a direct connect. But, it is good to know that electronicsNmore also provides an indicator circuit in his video, and the circuit can be used for whatever your needs may be.

Thank you to electronicsNmore on YouTube, and to Swagatam Majumdar at Homemade Circuit Just For You.


Video from electronicsNmore:




Amazon "High Quality KSD9700 250V Bimetal 45 Celsius NC Temperature Control Switch Pack Of 10." 

Amazon "10 Pcs Bimetal Temperature Control Switch Thermostat 40C N.O TLRS9700"
." 
YouTube video link:

Super Simple Temperature(Heat) Activated LED/Cooling Fan Circuit

Update 12/16/2014:   

O.K., new thought there. I am thinking I can use his circuit with a slightly higher temperature for a automatic shutdown to prevent overheating. Maybe place it downstream of the "On" LED (part of the inrush protection circuit), and downstream of the fan so that the fan keeps cooling after the circuit shuts down. He also has an indicator light circuit in this video that I can use when the shutdown kicks in. Great. Don't want to start a fire or ruin the parts....