Hello guys, you know the importance of "if-statement " in programming but How you can Do if-statement with electronics?
We will do this by comparator:
In electronics, a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger. It has two analog input terminals; A comparator consists of a specialized high-gain differential amplifier. They are commonly used in devices that measure and digitize analog signals, such as successive approximation ADCs, as well as relaxation oscillators.
DAC with comparator 
Let’s do this algorithm:
power supply circuit:
We will use 12 v low-frequency transformers with bridge followed by filter capacitors.
Explanation of the circuit the Zener will make the volt staple at 5.1v on inverting pin of an op-amp, volt that is compared it will come from the pot
By variation, the pot: if the volt is more than 5-volt op-amp output is 12v led is on
Else "less than 5v the output will be zero led is off
Full circuit:
Link of the circuit:
https://drive.google.com/file/d/1RdJJluzjKoBIZ2Ho1AM5C_G-Spf0ukTe/view?usp=sharing
feel free to ask me any question:
Gmail: eng.darwishelectronics@gmail.com