Maker Factory ELECTRONICS EXPERIMENTS BOX Manual page 270

Circuits 66 and 67: The different values of R2 and R4 achieve different levels of voltage drops via R3 in
the states On or Off. The difference between these two voltage drops corresponds to the hysteresis of the
Schmitt trigger.
272
Fig. 3.66: Circuit
66 – Schmitt trig-
ger circuit with
4V hysteresis
Fig. 3.67: Circuit
67 – Schmitt trig-
ger circuit with 2V
hysteresis