![]() ![]() Since these are already voltages, it will be easier to influence them.Īdding or subtracting a constant voltage from the non-inverting input makes no sense as it will simply shift both switching levels. How can we change this into something that can be controlled by a voltage? As it seems difficult to turn the time constant R1-C1 into a voltage-controlled time constant, using the comparator switching levels instead may be a better option. Simplified schematic with an AD8542 (included in LTSpice) to make it run from a single supply. The comparator switching levels that are now set at 91% of the output voltage.The time constant R1-C1 has become 100 kΩ * 10 nF = 1 ms.For R2 however, this is obligatory as we want the voltage on the non-inverting input to swing around 2.5 V. ![]() The comparator switching levels set at 90% of the output voltage.įor experimenting purposes I changed the circuit a bit into a single-supply circuit oscillating at about 170Hz.Ĭ1 is not connected to half the supply voltage as that isn’t necessary (try for yourself in LTSpice or on a breadboard).The time constant set by R1 and C1, which is 100 kΩ * 3.3 ♟ = 330 ms.The output frequency is determined by two parameters: The circuit is a simple square wave oscillator with an output frequency of around 0.5 Hz. We start with a circuit from the Texas Instruments’ datasheet for the TL082. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |