Electronic Circuit Projects
The Projects:
For this project, a kit was used to construct ten electric circuits that performed various tasks, usually with a breadboard and a kit that came with all of the components needed to construct the circuits.
The first circuit consisted of a resistor and a light emitting diode. The basis of the circuit was to demonstrate how the resistance of a circuit inversely affects the current. This can be seen by how the brightness of the lightbulb changes when the resistor in place changes, the more resistance in the circuit, the less bright the LED is, and vice versa.
The second circuit worked with a potentiometer, along with an LED and a resistor. The potentiometer works as an adjustable resistor. When the dial on top of the potentiometer is turned, the brightness of the LED changes, in the same way that changing a resistor would.
The third circuit demonstrated how a photocell works. A photocell is a component that affects the circuit based on how much light is available. When the photocell was covered by someone's hand, it reduced the current in the circuit (which could be seen by using an LED), when it was left uncovered, in a bright environment, the LED in the circuit would become brighter, indicating increased current.
The fourth circuit worked with a capacitor. A capacitor is a device that stores energy and releases it back into the circuit. Using an LED, it could be seen that when the battery was disconnected, the LED remained glowing for a short period of time. The larger that the capacitor was, the longer the LED remained Illuminated.
The fifth circuit demonstrated how a speaker works. By running electricity through an electromagnet, the magnetic field inside the speaker changes. When this happens, a cone inside the speaker moves, this is what creates sound. By continuously disconnecting and reconnecting the circuit, the cone continually moves, making sound. A speaker for a radio works because of the signal being sent to the radio. The signal is a constantly fluctuating series of electrical information. By running this signal through the electromagnet, the cone moves in a way that the music that the radio station is broadcasting is played through the speaker.
The sixth circuit demonstrated how a diode works. A diode acts like a door that electricity can only pass through in one direction. This may sound simple, but it is actually used in many places, like the batteries on a cell phone for example, when the battery is charging, the electricity can pass into the battery, but cannot leave it, because of a diode.
The seventh circuit implemented an SCR. An SCR acts in a strange way; electricity can only flow through it after it has received an activation current. An SCR acts like a gate for electricity to flow through, but only after it has been 'unlocked' after the activation current changes it's properties.
The eighth circuit (above right) used an NPN transistor to show how amplification works. An NPN is a transistor that has a Positive collector, a negative emitter and a slightly positive base. It was in parallel circuit. The NPN controlled the current flowing through each of the individual circuits. One current was a Base current, which was small, and a collector current, which was larger. The base current, however, controls the collector current. When the base current is increased, the collector current increases proportionally, the collector current is amplified.
The ninth circuit was similar to the eighth, except that it used a PNP instead of an NPN, Its collector was negative, its emitter was positive and its base was slightly negative. The circuit worked in the same way, except that the collector current and the base current were switched.
The tenth circuit (above left) was an oscillator. The Circuit used an NPN a PNP a disc capacitor and a speaker. When activated, the speaker would make a constant tone. This is because the current was constantly changing. The constant change in the current throughout the speaker was maintained by the feedback from the output of the speaker to the input of the NPN, through the disc capacitor. The frequency that the current changed was determined by the size of the capacitor and the amount of resistance in the different parts of the parallel circuit. The larger the transistor and resistor, the greater the frequency of change. This is called oscillation.
For this project, a kit was used to construct ten electric circuits that performed various tasks, usually with a breadboard and a kit that came with all of the components needed to construct the circuits.
The first circuit consisted of a resistor and a light emitting diode. The basis of the circuit was to demonstrate how the resistance of a circuit inversely affects the current. This can be seen by how the brightness of the lightbulb changes when the resistor in place changes, the more resistance in the circuit, the less bright the LED is, and vice versa.
The second circuit worked with a potentiometer, along with an LED and a resistor. The potentiometer works as an adjustable resistor. When the dial on top of the potentiometer is turned, the brightness of the LED changes, in the same way that changing a resistor would.
The third circuit demonstrated how a photocell works. A photocell is a component that affects the circuit based on how much light is available. When the photocell was covered by someone's hand, it reduced the current in the circuit (which could be seen by using an LED), when it was left uncovered, in a bright environment, the LED in the circuit would become brighter, indicating increased current.
The fourth circuit worked with a capacitor. A capacitor is a device that stores energy and releases it back into the circuit. Using an LED, it could be seen that when the battery was disconnected, the LED remained glowing for a short period of time. The larger that the capacitor was, the longer the LED remained Illuminated.
The fifth circuit demonstrated how a speaker works. By running electricity through an electromagnet, the magnetic field inside the speaker changes. When this happens, a cone inside the speaker moves, this is what creates sound. By continuously disconnecting and reconnecting the circuit, the cone continually moves, making sound. A speaker for a radio works because of the signal being sent to the radio. The signal is a constantly fluctuating series of electrical information. By running this signal through the electromagnet, the cone moves in a way that the music that the radio station is broadcasting is played through the speaker.
The sixth circuit demonstrated how a diode works. A diode acts like a door that electricity can only pass through in one direction. This may sound simple, but it is actually used in many places, like the batteries on a cell phone for example, when the battery is charging, the electricity can pass into the battery, but cannot leave it, because of a diode.
The seventh circuit implemented an SCR. An SCR acts in a strange way; electricity can only flow through it after it has received an activation current. An SCR acts like a gate for electricity to flow through, but only after it has been 'unlocked' after the activation current changes it's properties.
The eighth circuit (above right) used an NPN transistor to show how amplification works. An NPN is a transistor that has a Positive collector, a negative emitter and a slightly positive base. It was in parallel circuit. The NPN controlled the current flowing through each of the individual circuits. One current was a Base current, which was small, and a collector current, which was larger. The base current, however, controls the collector current. When the base current is increased, the collector current increases proportionally, the collector current is amplified.
The ninth circuit was similar to the eighth, except that it used a PNP instead of an NPN, Its collector was negative, its emitter was positive and its base was slightly negative. The circuit worked in the same way, except that the collector current and the base current were switched.
The tenth circuit (above left) was an oscillator. The Circuit used an NPN a PNP a disc capacitor and a speaker. When activated, the speaker would make a constant tone. This is because the current was constantly changing. The constant change in the current throughout the speaker was maintained by the feedback from the output of the speaker to the input of the NPN, through the disc capacitor. The frequency that the current changed was determined by the size of the capacitor and the amount of resistance in the different parts of the parallel circuit. The larger the transistor and resistor, the greater the frequency of change. This is called oscillation.
Robotic circuit projects.
For this project, the same kit from the electronic circuits was used to create multiple circuits that performed different tasks. I only made it through the first circuit, because of the pressure from the approaching end of the school year (time constraints). The first circuit used the robotic circuit board (already assembled) and a 555 timer chip transistor. When electricity flowed through the circuit, the 555 transistor sent it to the robot's circuit board, which in turn directed the motors of the robot turn on for a short period of time, and then stop. This created a jerking foreword movement. The secret was in the transistor. The transistor basically worked like a post office, electricity would enter the chip, and it would re-direct it to somewhere else.