why 555 timer is called 555 timer?

why three resistors of 5 ohm is used in 555 timer and why not other resistance of different values will be used ?

Posted by sunilmoonat on 24/04/2007, at 07:38 GMT

555 timer

The '555' is the part number of the timer IC (integrated circuit), it doesn't refer to resistor values. For suitable resistor values for the various 555 timer circuits please see the Digital Electronics section of this website.

Posted by John Hewes on 24/04/2007, at 15:14 GMT

why 555 timer is called 555 timer?

thankyou for sending me the answer but i can't understand it
what did you mean that 555 is the part number of the timer IC?

Posted by sunilmoonat on 26/04/2007, at 13:24 GMT

555 timer

A 555 timer circuit is made up from several electronic components: a capacitor, at least one resistor, and the timer IC (often called a 'chip' this has the part number '555'). The IC controls the circuit (like a brain). The values of the resistor(s) and capacitor determine the timing. There are several types of timer circuit with different functions. Please see the Digital Electronics section of this website for further details.

Posted by John Hewes on 26/04/2007, at 14:20 GMT

555 timer

The 555 timer is called because of the internal 5k resistor network that sets the trigger and threshold voltages for the 2 comparators that operate the flip/flop circuit. Further details in data sheets and explanation given.

Posted by Robert Neill on 01/04/2010, at 11:12 GMT