Wednesday, September 30, 2009

low voltage alarm


Schematic for Low Voltage Alarm

Parts:


Part

Total Qty.

Description

R1, R3

2

1K 1/4W Resistor

R2

1

5K Pot

U1

1

LM339 Voltage comparator IC

D1

1

1N5233B Zener Diode

D2

1

LED

BZ1

1

Piezo Buzzer

MISC

1

Board, wire, socket for IC

Notes:

1. The circuit will operate from 9V to 12V.

2. Adjust R2 until the alarm goes off at the correct voltage.

Tuesday, September 29, 2009

quote of the day

Those who are afraid to fall, will never fly

dark activated switch

Dark-activated Flasher



Parts:

R1_________________Photo resistor (any type)
R2________________100K 1/2W Trimmer Cermet
R3,R4______________10K 1/4W Resistors
R5________________470R 1/4W Resistor
R6_________________47R 1/4W Resistor

C1________________220΅F 25V Electrolytic Capacitor

D1______________1N4148 75V 150mA Diode
D2_________________LED Any type and color (See Notes)

Q1,Q2____________BC337 45V 800mA NPN Transistors

SW1_______________SPST Switch

B1__________________3V (Two 1.5V AA or AAA cells in series, etc.)



Circuit operation:

This circuit adopts the rather unusual Bowes/White emitter coupled multivibrator circuit. The oscillation frequency is about 1Hz and is set by C1 value. The LED starts flashing when the photo resistor is scarcely illuminated. The onset of flashing can be set by trimming R2.

Notes:

  • Best results in flashing frequency can be obtained using for C1 a value in the 100 to 1000΅F range.

  • To drive a filament lamp the following changes must be made:


    Use a 2.2 to 3V, 250-300mA lamp in place of the LED

    R2 = 10K 1/2W Trimmer Cermet

    R3, R4 = 1K 1/4W Resistors

    R6 = 1R 1/4W Resistor

    C1 = 470 to 1000΅F 25V Electrolytic Capacitor


  • In LED-mode operation the stand-by current consumption is less than 400΅A.

  • In Lamp-mode operation the stand-by current consumption is about 3mA.

solar installation

Solar Panel Installation Techniques
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AMECO Solar sun logo PV InstallationSolar panels on the north, south and east roof exposures

Solar photovoltaic panels can be installed on many different types of roofs.

Panels can be flush mounted as well as tilted up.


When ever possible it is best to install solar panel mounts while a home is being re-roofed.



Solar mounts "flashed-in" during the roofing process will eliminate any possibility of roof leaks.



It is also much easier to locate rafters when the roof is off.

Tilt up mounts

All mounts need to be secured onto the roof with stainless steel lag bolts bolted through into rafters.



Having structural attachment points "flashed-in" is a wise wise method of installing solar panels, and the future cost of removal and re-installation of solar panels can be avoided for decades.



Composition shingle roofs are the easiest to work with. Tile roofs are more challenging and carrying solar panels across them can be like walking on egg shells.

line

PV Installation

The installation procedure below demonstrates how to mount solar photovoltaic panels on a sloped roof

This installation also shows how to incorporate solar mounts into a new roof

photovoltaic solar energy array
STEP 1.
AMECO uses Professional Solar Products "FastJack" and "Tile Trac" solar panel mounts to structurally attach solar panels to a roof.
"Fast-Jack" solar panel mounts

STEP 2.

Align mounts on top of rafters, then pre-drill with a pilot bit to avoid splitting the rafters. The rafters can be found with a stud finder.

Use a chalk line or laser sight to keep the mounts in a straight line.

Fast Jack

STEP 3.

Secure the mounts to the roof with stainless steel lag bolts. The roof on this house was brand new but looked sloppy, so a new layer was applied around the mounts.

posts secured

STEP 4.

Metal flashing's were placed over the mounts and the layer of roofing was hot-mopped around the mounts.

Metal rails are secured to the posts with 3/8' stainless steel bolts.

rails secured

STEP 5.

Next we install the solar panels and connect them into an array.

panels are mounted

STEP 6.

The final step is to run the conduit to connect the panels to the inverter.

nice looking installation
This installation is a low profile, unobtrusive, clean, green energy making machine 40 Siemens solar modules

Solar Photovoltaic System Installation Photos

Thursday, August 27, 2009

political corruption in nigeria

Political corruption in Nigeria encompasses the use of official power and government resources for sordid and disrepute private gain. Political corruption is not a recent phenomenon that pervades the Nigerian state, since the creation of modern public administration in the country, there have been cases of official mis-use of resources for personal enrichment.[1] The rise of public administration and the discovery of oil and natural gas are two major events seen to have led to a litany of ignoble corrupt practices in the country. Over the years, the country has seen its wealth withered with little to show in living conditions of the common man. A Nigerian political leader, Obafemi Awolowo raised a salient issue when he said, since independence, our governments have been a matter of few holding the cow for the strongest and most cunning to milk, Under those circumstances everybody runs over everybody to make good at the expense of others.[2] Characteristically, apologists for the failings of African governments have blamed colonialism for the pervasive corruption. According to this view, the nation's colonial history may have restricted any early influence in an ethical revolution. Throughout the colonial period, most Nigerians were stuck in ignorance and poverty. The trappings of flash cars, houses and success of the colonists may influence the poor to see the colonist as symbols of success and to emulate the colonists in different political ways. Involvement in the agenda of colonial rule may also inhibit idealism in the early stage of the nascent nation's development.

Wednesday, August 26, 2009

Tuesday, August 25, 2009

solar panel installation

PV Installation

Solar photovoltaic panels can be installed on many different types of roofs. Panels can be flush mounted as well as tilted up.

When ever possible it is best to install solar panel mounts while a home is being roofed.

Solar mounts "flashed-in" during the roofing process will eliminate any possibility of roof leaks.

It is also much easier to locate rafters when the roof is off. All mounts need to be secured onto the roof with stainless steel lag bolts bolted through into rafters.

Having structural attachment points "flashed-in" is the most wise method of installing solar panels, and the future cost of removal and re-installation of solar panels can be avoided for decades.

Composition shingle roofs are the easiest to work with. Tile roofs are more challenging and carrying solar panels across them can be like walking on egg shells.

Solar panels on the north, south and east roof exposures

Tilt up mounts

8 Siemens SP-75's

PV Installation

The installation procedure below demonstrates how to mount solar photovoltaic panels on a sloped roof. This installation also shows how to incorporate solar mounts into a new roof.

photovoltaic solar energy array

STEP 1.

GO Solar Company uses "FastJack" solar panel mounts to structurally attach solar panels to a roof. The mounts are secured before the new roof is applied. For existing roofs we utilize "TileTrac" mounts.

"Fast-Jack" solar panel mounts
(a unique patent pending design)

STEP 2.

Align mounts on top of rafters, then pre-drill with a pilot bit to avoid splitting the rafters. The rafters can be found with a stud finder.

Use a chalk line or laser sight to keep the mounts in a straight line.

Fast Jack

STEP 3.

Secure the mounts to the roof with stainless steel lag bolts. The roof on this house was brand new but looked sloppy, so a new layer was applied around the mounts.

posts secured

STEP 4.

Metal flashings were placed over the mounts and the layer of roofing was hot-mopped around the mounts.

Metal rails are secured to the posts with 3/8' stainless steel bolts.

rails secured

STEP 5.

Next we install pre-assembled and hard wired solar panels in groups of 4.

No "quick connections" are used on our wiring.

This array holds 20 of a total of 40 Siemens panels installed.

panels are mounted

STEP 6.

After the solar panels were in place a layer of reflective roof coating was applied to the roof.

The final step is to run the conduit to connect the panels to the inverter.

nice looking installation
This installation is a low profile, unobtrusive, clean, green energy making machine. 40 Siemens solar modules