hi
i'm having a bit of troubles calculating an adecuate resistor for this opams
here's my schematic. asume potentiometers are set to 50-50, vcc is 5V, R42 = R43 and R14 = R15. lets call the line that gets lost to the left X and REG goes to a microcontroller
with this, I'm monitoring X: if X goes out of a range set by the pots, the opams are supposed to set REG to high. but the current values i calculated for the resistors set a very wide histeresis window for both opams that overlap so the signal is ALWAYS set to 1 xept when i'm from 2.8 to 3.2 V aprox (VERY narrow acceptance margin) and i need to set this values farther appart!
lets say, the lower opam should turn on below 1.5V and off at 1.8V, while the upper opam should turn on avobe 4.5V and off at 4.2V (this ARE NOT accurate values, i must be able to adjust them with the pots; i just wrote them as an example)
i want the equation to get the resistors, not quite the values the resistors must have
can anyone help me figuring this out??
i'm having a bit of troubles calculating an adecuate resistor for this opams
here's my schematic. asume potentiometers are set to 50-50, vcc is 5V, R42 = R43 and R14 = R15. lets call the line that gets lost to the left X and REG goes to a microcontroller
with this, I'm monitoring X: if X goes out of a range set by the pots, the opams are supposed to set REG to high. but the current values i calculated for the resistors set a very wide histeresis window for both opams that overlap so the signal is ALWAYS set to 1 xept when i'm from 2.8 to 3.2 V aprox (VERY narrow acceptance margin) and i need to set this values farther appart!
lets say, the lower opam should turn on below 1.5V and off at 1.8V, while the upper opam should turn on avobe 4.5V and off at 4.2V (this ARE NOT accurate values, i must be able to adjust them with the pots; i just wrote them as an example)
i want the equation to get the resistors, not quite the values the resistors must have
can anyone help me figuring this out??