by admin | Mar 16, 2014 | Tech Updates
The Bohol Chamber of Commerce and Industry held its annual general assembly on March 15, 2014 at the Dagohoy Hall at the Bohol Tropics Resort, Tagbilaran City. The governor of the province, Gov. Edgar M. Chatto and the city administrator of Tagbilaran, Mr. Leonides L. Borja on behalf of City Mayor John Geesnell Yap, represented the government sector. Atty. Emmanuel Aladin D. Tumanda presented the president’s report which included an audio-video presentation showing the year’s activities of the chamber. The organization was deeply involved in relief efforts after the 7.2 magnitude struck the province on October 15, 2013. Senator Paolo Benigno Aquino IV was the guest speaker and his message to the chamber is “jobs and enterprise for inclusive growth”. The senator is promoting support structure for the small enterprises. A bill authored by the senator called “Go Negosyo” is nearly passed as a law and it will help small enterprises. The chamber also held the election of the board of trustees as well as inducted its new...
by admin | Mar 8, 2014 | Tech Updates
It is a common practice for service companies like hotels, resorts and restaurants to be providing WiFi Internet access to its customers. However, there is a common mistake also for such companies. The WiFi network is on the same network segment as the office computers. This is a security issue because now you are allowing strangers to have local network access to your computers. In order to avoid the issue where the WiFi users can access your local network, the office network must be on a separate network segment, with its own router and firewall blocking any unauthorized access from outside the network. Another concern with sharing Internet access to customers is that your own Internet access might become slower also because of the increased download and upload activity. There are firewall devices available on the market that allows you to segment the network into two or more subnets. You can put the office network on one subnet and the customer WiFi access on the other. Then on the firewall, define the rules such that incoming traffic from the customer subnet is blocked if it is going to the office subnetwork. With a little change on the network configuration, one can increase the computer network significantly. With the constant threat of malicious Internet activity, it is important for business owners to secure their computer network to protect its business...
by admin | Mar 8, 2014 | Tech Updates
by: Jerome Auza Before I had setup my experimental solar power system, a power interruption like that scheduled on March 9, 2014 would mean that we need to purchase gasoline worth around Php800.00 to keep the office network running. It’s probably more expensive these days with the gasoline hitting the Php60.00/liter mark. I checked my solar system today and I have 57% charged batteries. The system seemed to have charged slowly the past two days. I expected close to 100% charge after two days with lots of sunshine. This is something for investigation later. However, at this time, what I need to know is how long can I run the network without resorting to the generators. If the sun is out most of the day during the power interruption, I would expect to be able to run the network for at least 10 hours. To be sure, I plan to turn off some of the non-essential equipment like that powering up the LAN of the office since there will be nobody working. My wife who runs a maternity clinic at Talibon, Bohol has her own solar system also and is currently fully charged and should enable her to run the most important equipment at her clinic during the power interruption. Services like ultrasound and fetal montiring for her patients at St. Gerald’s Maternity and Wellness Clinic should continue even without electricity. I have one 300W solar panel coming soon so the articles in the coming weeks should be interesting since I can start configuring the system to run the office network 24/7 on solar power. I’m still a long...
by admin | Feb 22, 2014 | Tech Updates
After installing my battery monitor, it became very convenient now to get a reading for both voltage and current. Just a few presses of a button and I could get the two values straightaway. One more number the battery monitor displays is the percentage of the battery capacity. Knowing how much energy is left on the batteries while running a large load is very useful just like during the power failure on the morning of Friday, February 21. In the past, I would run to my generator and start it and transfer the power of the office network to the generators. Last Friday, I used my solar energy system and was able to support the load for the duration of the power failure. Because my battery monitor showed me the percentage of charge left (I had the perimeter lights on the system the previous night), I knew the system can run on the batteries for at least five hours. At this time, my experiments on the solar energy system will be put on hold until I am able to acquire large solar panels. If there are individuals or organizations who are willing to help me complete my setup and my experiments, please email me at jerome.auza@auza.net or call me at 09178898932 and we can discuss the details. I hope my experiments can encourage the use of renewable energy systems and help reduce the cost of...
by admin | Feb 22, 2014 | Tech Updates
By Jerome Auza The term ‘hackers’ used to mean something positive among computer programmers. If you are able to make a program that solves a complex computing problem, you will be called a hacker. It is a badge of honor. Until someone used the word hacker to describe someone that does malicious programs. Nowadays, people who make computer viruses and malware, or people who make attempts to defraud or steal sensitive personal information. Today’s work, entertainment and personal communications involve computers and mobile devices on a very large scale and it becomes very important to keep your personal information secure. In the 1990’s, computer viruses created by “hackers” were mostly created to destroy computer data and annoy users. Back then, computer networks is not common. In the present, most computers and mobile devices are connected to the Internet and the nature of “hacking” changed from data destruction and annoyance to fraud and theft of personal information. Software that does the work of the “hacker” is commonly termed malware. A lot of malware can be running on your computer without your knowledge because all it does is collect personal information and send that to its creator in a sneaky manner which is mostly undetected. The longer it stays there, the bigger chance it will be able to get your personal information that becomes useful to the “hacker”. Once your personal information is stolen, the “hacker” can then pretend to be you and maybe send emails to your contacts asking for money because “you” are in a foreign country and have lost all your things because you were mugged. Your helpful...
by admin | Feb 8, 2014 | Tech Updates
It might just be coincidence, but I think Mother Nature has a sense of humor. Last week, I said that I will start saving money at Auza.Net by putting our perimeter lights on the solar system. The days following that “historic” day for Auza.Net were cloudy and of course, my solar panel system soon ran out of stored energy after just two and a half nights. Just the same, I saved a few kilowatt-hours and maybe about Php30.00. That also got me into thinking that my assumptions on how much energy is actually produced and stored could be wrong. I should really need to understand the dynamics of the energy production in relation to the weather for a successful solar energy system. Fortunately, my battery monitor which was purchased in the US arrived late last week and after I installed it on the system, I am able to conveniently measure voltage, current and the battery state of charge. The key item in the installation of the battery monitor is the shunt resistor (with 500A/50mV rating) which is a precision resistor designed for accurate measurement of current going through it. This replaced my home made shunt resistor described in an article a few weeks back. Also, I placed this shunt resistor at the negative terminal instead of in-between the two batteries since the battery monitor also measures the total voltage of the battery which it cannot do if the shunt resistor is placed elsewhere. One might ask why I am going through the trouble of accurately measuring current and voltage. Why not just buy a large solar energy system and...
by admin | Feb 1, 2014 | Tech Updates
After a few months experimenting with solar energy generation in my spare time, I finally was able to start using the system to power up some of our lighting requirements. We have about seven CFL bulbs lighting our right of way and part of the perimeter fence at night. This is controlled by an optical switch that automaticall turns on the lights when it is evening and turns them off in the morning. I measured about 120W of power drawn from the battery for all the lights. Assuming the lights are on 12hours, I will be saving about 1.44kWhr per day or about 43.2kWhr per month. At Php8.5/kWhr, this amounts to Php367/month. This doesn’t seem much but this actually means that I only need to increase battery storage capacity and also solar panel generating capacity and I can increase my savings gradually until I get free electricity. My solar panel, after checking it again, actually has a capacity of 128W and not 100W as I mentioned before. This means I have only less than 10W reserved generating capacity to allow for cloudy days. So I will change some of the bulbs to a slightly lower power rating in order to keep the power consumption at about 80W. I also plan to add another set of batteries to make my total storage capacity of 400AH because during brownouts, I can also use the system to power up my network equipment that consumes about 230W. I can avoid using the generator if the power interruption is only for short periods. This is handy for night time power interruptions because the generator...
by admin | Jan 25, 2014 | Tech Updates
Finally, after a few weeks without sunshine, the weather cleared up and the sun was shining brightly and the batteries on my solar energy system finally got some serious charge, reaching close to full charge by Friday afternoon. It was also the ideal time to take current measurements and figure out what should be expected of a solar energy system in different weather conditions. For optimal energy production, a solar panel should be inclined about 30 degrees facing south. The panel I used is installed on a roof deck tent structure which is currently not an ideal position for a solar panel. It is facing east more than it is facing south, thus, solar energy production is highest between 10AM to 12NN and would start to decrease by 1PM. That means I should soon modify the roof deck structure so that the panels are in the ideal position. I took various measurements of the current going into the batteries when the clouds cover is very thick, when there is just a thin layer of clouds and when the sun is fully out. This week, I was taking measurements between 10AM to 12NN so I can compare the results for various cloud coverage. When tropical depression Agaton was still in full swing, cloud cover was very thick and the sun was never out. In a previous issue, I measured about 0.4 to 0.7A at about 4PM. I measured between 0.6A to 1.1A between 10AM to 12NN. Last Thursday and Friday, the cloud cover was such that the sun would be fully out for a few minutes then get covered again....
by admin | Jan 18, 2014 | Tech Updates
The sun hasn’t been out for almost two weeks now and my batteries are still not fully charged even if it has been charging for a week after I drained it last week. I now must find out why it is taking so long to recharge in cloudy conditions. In theory, my 100W, 24V solar panel should produce 4.1A of charging current during sunny conditions. 4.1A should fully charge my 100AH, 24V battery setup in 24 hours of sunshine which should be just 2 to 3 days. But because of the the low pressure area (and now a tropical depression), the weather has been cloudy for almost two weeks now. So how much charging is being done in cloudy conditions? Because I don’t have a battery monitor yet, I just created a make-shift shunt resistor. It is basically a resistor with very low resistance and high current capacity. The smallest resistor I could find was a 0.22ohm, 5W resistor. To measure current, I simply need to get the voltage through a known resistor value and use the equation: I = V/R. I also don’t want to introduce a large voltage drop between the batteries and the charge controller and inverter because it would affect charging. I expect to measure about 5A of current and the voltage drop would be V = IR or 5 * 0.22 = 1.1V. This is actually too large. The solution is to connect several resistors in parallel which reduces the resistance. I soldered together eight 0.22 resistors in parallel to get a combined resistance of 27.5mOhm. The voltage drop of 5A across it would...
by admin | Jan 11, 2014 | Tech Updates
By: Jerome Auza Last week was a very good opportunity to test my small solar energy system and how it would fare in cloudy weather providing power for two computers. I started with fully charged batteries on Monday connected to a 600 watt pure sine wave inverter and two laptops with 65 watts and 85 watts power supplies. I guessed that the two laptops will only consume half of their rated power consumption during use between 9AM to 6PM and would be on standby during the night and therefore consume little power. The 100W solar panel should be enough to power them during the day and keep the batteries charged assuming the panel gets enough sunlight. But it was cloudy and rainy most of the week. The setup worked fine until Friday morning when the inverter shut down due to low battery voltage. At 9AM, I can see that the batteries have charged up a bit so I turned on the inverter and plugged the 85W laptop only. By noon, the inverter shut down again which means the power generated by the panels is not enough to power the laptop and the inverter, thus draining the batteries. The weather was still very cloudy. I let the batteries charge until Saturday without any load but by 5PM Saturday, the battery is still considered less than 40% charged based on the indicators of the solar charge controller. The weather, was still cloudy most of Saturday. This got me into thinking that I should be able to see if my setup is charging or discharging the batteries when a load is applied....
