My Construction Project published in EFY-sept-09 issue

Hello Forum members,

iam happy to inform that my construction project " Microcontroller based Solar Charger Controller " has been published in the popular EFY ( Electronics For u) magazine September 2009 issue, page number 58. this is my second project that has appeared in EFY, first was Digital Speedometer in November 2008.
my other projects too will be published turn by turn

Hope you guys will go thru and enjoy !







Arun Kumar

congrats arun, expecting more projects from you in future.

[Check out the new 8051 blog]

Thanks binu,

So you are back from the big show in Germany. Congrats to you too for winning Nokia contest. [^]


Arun

Hello Arun.I was doing a project for my last year paper on"Microcontroller based Solar Charger Controller " that was published in EFY September 2009 issue, and I faced some confusions regarding how to program the microcontroller and how to interface the 16x2 LCD display plus how to connect the relay on the PCB .I also need a detailed guide line on how to interface a lower voltage solar panel since the mentioned (10-40 watt) solar panel price is expensive here in Pune city. I would be happy if u clarify my doubts and help me to bring this inteliligent circuit to life.Thanx

My dear Friend the "intelligent" circuit has already come to life and is working since 1 year at several places( nearly 50 units are working) with out any problems.

regarding the low wattage solar panel, you can use any wattage solar panel as long it is meant to charge a 12V battery. you can even use 1watt panel. the circuit can be used with out any changes.

all the details of the project are published in the EFY mag along with Hex file and source code.

Relay has to be connected externally and not on the PCB.

to program the hex file into the micro either you have to buy or build a programmer.

Arun

Hellow Mr Arun again !Thanx for the immediate reply you posted but I still wanted to ask you a few more details.
The "suger cube relay"(12V,1C/O relay) that is meant to be connected externally has five pins and of which- one is
pole,2 coil-contact terminals and 1 n/o and 1 n/c contact.Now my question is that while making
the relay connection externally, should I need to leave the n/o contact floating(with no connection) as per the circuit diagram ? And are the 2 coil-contacts of the relay polarity sensitive? Other question is that
if the solar panel is it meant to be connected through D1 (6A4 rectifier diode) ,should I also need to connect
it externally just like the relay ?(because the doide 1 connnection is not shown in the component layout given.)
Another question is regrding the files given in the CD.Are the codes for the LCD included in the the hex file given
that need to be burnt on the moicrocontroller at once or does it need to be programmed separately? and plz
verify me with what kind of on-board connectors I should use to connect the LCD.I will again appreciate for
any reply that you post to help me.
(reply me via scooby_fy@yahoo.com directly if possible so that I can write you when I get stuck )
David

Hi Arun ! I didnt get any reply from you so far and patiently waiting for you to post soon

Hello, Sir we are doing a similar project. We have got some doubts.
1. During the daytime the 10k resistor is connected to the collector of t1(BC547) which is shorted.Will the resistor be heated enormously.
2. If due to some short circuit the battery voltage goes below 5V how will the microcontroller and its accessories work or continue its rest of operation
Expecting ur reply as early as possible.

Thanks tibbu, for replying to the queries.

@ arunintel772

1. During the daytime the 10k resistor is connected to the collector of t1(BC547) which is shorted.Will the resistor be heated enormously.

There won't be any heat in the resistor because, the resistor is a quarter watt one i,e 250milliwatts and the current passing thru it is 500microamps, we can calculate the power wasted/handled in the resistor using I2R ,i ,e = 500uA X 500uA X 10,000 Ohms which is = 2.5 milliwatts and our 10K, 250 mW resistor can handle 100 times what we are using, so it remains cool. Got it!

2. If due to some short circuit the battery voltage goes below 5V how will the microcontroller and its accessories work or continue its rest of operation

Battery is connected in front of the 5Volts Regulator( 7805) and if it is shorted, then the voltage at input terminal of 7805 will be 0V, so the Regulator internally shutsdown (i,e no output), obviously the micro and its associated circuitry won't function and are reset when the short circuit condition is removed - but beware the battery will be destroyed within few seconds or its life will shortened. on the other hand, if the load is shortcircuited, then the 10A fuse will blow out thereby protecting the battery

Arun