Question

In the final project, students will design a motor controller based on the light level on a phototransistor: When illumination is very high, the motor will be stopped 6V will be applied to the motor under low light conditions: The circuit must provide at least 60 mA at 6V to the motor. If the motor is stalled, the maximum current shall not exceed 150 mA. . You will need to measure (characterize) the properties of the phototransistor under both light and dark conditions in order to design the circuit and calculate component values. Be sure to justify all component values and provide calculations for critical parts of your design. A table listing all components and briefly noting how values were derived is required. An op amp is be used in the project along with a TIP-29 or TIP-31 transistor. A 20 point penalty will be imposed if the circuit does not function. Good parts layout along with the use of bypass capacitors will greatly increase the likelihood that the circuit meets all specifications. Students working in a group of two will also need to provide an audio signal that is a function of the light level. Here, a 555 timer is to be used as a voltage controlled oscillator (VCO) that will generate a tone at a frequency of 500 Hz (+/-20%) at zero light level and 1000 Hz at full light (0 volts applied to motor). A small speaker or headset can be used to make the output audible and an oscilloscope can be used to verify the frequencies. One possible circuit is provided in the project data sheets folder (555CVCO.ASC) which can be used as a starting point. Students are free to use other circuits given on the web if they wish.

Please do a unique design including both parts. Thanks

Answer 1