User:Sajad hamze65

modern electronics make ever increasing use of digital electronic circiuty which respond only to signals that can only take uo either one of two logic levels.either the signal is high ,usually between about 2.5  to 5 V ,or it is low,usually between  aboute 0 to 0.4 v. information is transmitted in the from of number of voltage pulses that vary between the two values. for a pulse wave form to carry information or data some kind of code must be used. the basic code employed is the binary code but variouse extensions of this are aften employed. such as the ASC11 code and binary coded decimal.