NoiseFreeComparator-Schmitt Trigger its a functional board compatible with breadboard and arduino which make you can use it to extend your project easily. It can be use to detect 2 level signal like Comparator. But, if signal contain noise which fluctuate about some level voltage, NoiseFreeComparator-Schmitt Trigger is more preferable than Comparator. If we using Comparator with 1 point treshold voltage = Vcenter, the signal containing noise level near treshold voltage will cause fluctuative digital signal output which is undesired. If we using NoiseFreeComparator-Schmitt Trigger with 2 treshold voltage that is Vtrigger high and Vtrigger low, the noise level voltage between 2 treshold voltage can be neglected and will cause desired digital signal output.
NoiseFree-Schmitt Trigger Board uses is very wide, since it can replace Comparator. The application this circuit is are control something like light (Schmitt, 1938), smoke detector (Chaniotakis, 2006), Gamma Detector with PIN diode (Maxim, 2003), and the new voltage measurement method using stochastic resonance theory which can increase SNR (Harmer, 2002).
This Kit has functional input output Pin:
VCC= posistive supply
GND= negative supply
(VCC-GND range is 3.3V-12V, and arduino compatible)
NC= not connected
VIN= input signal
LOGIC= output signal (can be high or low)
Vtriggerlow is low treshold voltage, Vtriggerhigh is high treshold voltage. If Vtriggerlow exceeded, output LOGIC became low, and vice versa, if Vtriggerhigh exceeded, output LOGIC became high. The upper treshold is symmetrical to lower treshold with midpoint of VCC/2. In example if we set Vtriggerlow = VCC/2 - 1V, we automatically set the Vtriggerhigh = VCC/2 +1V, and vice versa. The Vtriggerhigh range is from (VCC/2) - VCC, and Vtriggerlow range is from GND-(VCC/2)
Is easy to set Vtriggerlow and Vtriggerhigh of NoiseFreeComparator Schmitt Trigger Board. Firstly, we need to turn potentiometer to clockwise direction until it maximum. Then, looking to first state LOGIC, if its high (LED is on), we must give input SIGNAL with same value as Vtriggerlow desired, then turn the potentiometer to counter clockwise direction slowly until LED start off, stop turning, and you has set the Vtriggerlow and Vtriggerhigh. Vice versa, if first state LOGIC is low (LED is off) we must give input SIGNAL with same value as Vtriggerhigh desired, then turn potentiometer to counter clockwise direction slowly until LED start on, stop turning and we has set the Vtriggerlow and Vtriggerhigh.