I'm trying to design a schmitt triger using a 741 opamp. Before building any circuit I thought of simulating it using multisim, but I ain't able to meet the requirements.. My goals was to let the trigger, trigger at top of 2 Volt and with a hysteresis of 1.6V it should trigger at 0.4V (bottom) too. I found these formules (see attachment) But i'm stuck... Such a simple schematic giving such problems Sorry for this stupid question :roll:
Hi,
Your formula or simulator has 2 problems:
1) It assumes that the output of the opamp goes rail to rail. An old 741 opamp's output will go to about only 1V from each rail (Us).
2) The DC voltage of the circuit's reference voltage, Ui, is ignored.