Week #4: PWM Circuits
Posted: Mon Feb 17, 2020 11:33 am
NOTE: Due to a difference between our lab equipment and what is specified in this lab, there are numerous adjustments and changes made to the schematics and tables in the handouts. Follow the modified directions on the lab sheet very carefully.
This week we will investigate the operation of two circuits which will create a PWM (Pulse-Width Modulated) output. You can download a copy of the experiment here in the Registered Users Only area. A hard copy will be provided for you in lab on Tuesday or Thursday.
Post your screenshots as a Reply to this Topic.
The first circuit uses the LM311 Precision Comparator which most of you used last semester for the Thermostat Temperature Comparator experiment, along with the LM34. There are additional handouts to explain the operation of the LM311 and the actual LM311 Data Sheet.
There is a second PWM circuit which makes use of a 555 Timer IC which will be used to create a PWM signal amplified by an NPN transistor to drive a 12V DC fan. You should take a few sample screenshots of the 555 output as well, noting the proportional speed of the motor at each Duty Cycle setting.
555 PWM Circuit Controlling a DC Motor The second lab circuit is based on this.
This week we will investigate the operation of two circuits which will create a PWM (Pulse-Width Modulated) output. You can download a copy of the experiment here in the Registered Users Only area. A hard copy will be provided for you in lab on Tuesday or Thursday.
Post your screenshots as a Reply to this Topic.
The first circuit uses the LM311 Precision Comparator which most of you used last semester for the Thermostat Temperature Comparator experiment, along with the LM34. There are additional handouts to explain the operation of the LM311 and the actual LM311 Data Sheet.
There is a second PWM circuit which makes use of a 555 Timer IC which will be used to create a PWM signal amplified by an NPN transistor to drive a 12V DC fan. You should take a few sample screenshots of the 555 output as well, noting the proportional speed of the motor at each Duty Cycle setting.
555 PWM Circuit Controlling a DC Motor The second lab circuit is based on this.