UFMFVA-15-1 EEPB Control Systems Tutorial Sheet was seen 1. The domestic toaster is an open-loop control system, suggest a mean by which it could be made a closed-loop control system 2. What percentage of the speed of a turntable rises if the error signal is increased by 2 volts? Assume the original speed was 200 RPM when a constant error of 10V (20%) 3. What are the demand voltages in a negative feedback speed control of a DC motor when the motor transfer function (T. Fn.) is 20 RPM/V to achieve a normal rated speed of the shaft? A total of 10 volts are seen as an error signal. Calculate the rated speed of the motor. In abnormal conditions, a sudden change of load on the shaft has reduced its speed by 20%; calculate suitable output volts of the tachometer (that is coupled with the motor shaft) when the T. Fn. of the tachometer is 0.025 volts/RPM. (assume the system is a linear system) (Demand voltage: 15V; Rated speed; 200RPM); Tachometer output: 5V at normal speed and 4V at reduced speed) Also, calculate: a. Closed-loop gain of the whole system. b. Open-loop gain of the system. c. Error transfer function. (13.33 RPM/volt) (0.5) (0.67) 4. A motor speed controller is required to maintain a speed of 5000 revolution per minute (RPM) with a varying mechanical load on the output shaft. The simplified transfer function (T. Fn.) for the motor is 500 RPM per amp. The power amplifier driving the motor has a T. Fn. of 1000 amps per volt and the tachometer which provides the speed feedback information has a T. Fn. of 0.5mV per RPM. a. What is the required input demand voltage to set the output at 5000RPM? (2.51 Volts) b. What is the open loop gain of the system? (250) c. What is the closed loop gain of the system? (1992.03) d. What is the error voltage when the motor speed is 5000 RPM? (10 mV) e. What is the motor current at this speed? (10 amps) UFMFVA-15-1 EEPB Control Systems Tutorial Sheet was seen 1. The domestic toaster is an open-loop control system, suggest a mean by which it could be made a closed-loop control system 2. What percentage of the speed of a turntable rises if the error signal is increased by 2 volts? Assume the original speed was 200 RPM when a constant error of 10V (20%) 3. What are the demand voltages in a negative feedback speed control of a DC motor when the motor transfer function (T. Fn.) is 20 RPM/V to achieve a normal rated speed of the shaft? A total of 10 volts are seen as an error signal. Calculate the rated speed of the motor. In abnormal conditions, a sudden change of load on the shaft has reduced its speed by 20%; calculate suitable output volts of the tachometer (that is coupled with the motor shaft) when the T. Fn. of the tachometer is 0.025 volts/RPM. (assume the system is a linear system) (Demand voltage: 15V; Rated speed; 200RPM); Tachometer output: 5V at normal speed and 4V at reduced speed) Also, calculate: a. Closed-loop gain of the whole system. b. Open-loop gain of the system. c. Error transfer function. (13.33 RPM/volt) (0.5) (0.67) 4. A motor speed controller is required to maintain a speed of 5000 revolution per minute (RPM) with a varying mechanical load on the output shaft. The simplified transfer function (T. Fn.) for the motor is 500 RPM per amp. The power amplifier driving the motor has a T. Fn. of 1000 amps per volt and the tachometer which provides the speed feedback information has a T. Fn. of 0.5mV per RPM. a. What is the required input demand voltage to set the output at 5000RPM? (2.51 Volts) b. What is the open loop gain of the system? (250) c. What is the closed loop gain of the system? (1992.03) d. What is the error voltage when the motor speed is 5000 RPM? (10 mV) e. What is the motor current at this speed? (10 amps)