From what I have understood, in the non-inverting schmitt Trigger,
- When Vin > Vut the output is High (Vout = VH)
- When Vin < Vlt the output is Low (Vout = VL)
And it is exactly the opposite in inverting Schmitt trigger,
- When Vin > Vut the output is Low(Vout = VL)
- When Vin < Vlt the output is High(Vout = VH)
where Vin --> Input Voltage, Vut --> Upper Threshold, Vlt -- Lower Threshold,Vout --> Output voltage.
The first line gives the output equation. Here they assume that the output is in high state. Then they find the Vut as shown. Here is where my question is, for the inverting case the output should be VL for Upper threshold. But in the expression for the Upper Threshold it is VH (Voltage high or +Vsat). Why is it so?