The cell we will use for our solar tracking experiment is made from crystalline silicon and has a maximum voltage rating of. 55V and a maximum current rating of 300 ma. The cell can be picked up in your local Radio Shack for about $5. Although the cell doesn`t produce much power, this experiment can certainly be scaled to handle higher wattages.
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Power is the measure of energy per unit time. It can be calculated by multiplying voltage by current at the output of the solar cell. Because our GP-3 Board can only measure voltage, we`ll need to create what is called a current-to-voltage converter circuit. This circuit takes current from the photovoltaic cell and runs it through a couple of operational amplifiers to produce a corresponding voltage (1V corresponds to about 10 milliamps). Figure 2 shows the circuit constructed for measuring current from the solar cell. The operational amplifier (also known as a differential amplifier) is a great circuit for sensing or measuring just about anything because it keeps the voltage at one input at a reference point determined by the other input. The first opamp is the current-to-voltage converter. It takes the current from the photovoltaic cell and converts it to a voltage determined by the 100 ohm feedback resistor. Unfortunately the voltage produced at the output of the first opamp is negative (which the A/D channel on our GP-3 board can`t measure). We need to flip the polarity of this voltage using a second op amp set up to invert the voltage sign. This positive voltage is then fed into pin 10 of our GP-3 board, which is actually channel #0 of our A/D (Analog to Digital) converter. The charting program consists of a User Control that plots data points on an XY Plotter. (See my previous article, An XY Plotter User Control in...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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