Automatic control starts loads softly
This entry was posted on Sunday, November 2nd, 2008 at 5:01 am and is filed under Electronic Control.
The components connected to 555 timer IC1′s pin 2 provide a trigger synchronized with the ac input’s zero crossing. In conventional 555 fashion, R1, R2, and Cdetermine IC1′s period. However, the RC delay network connected between IC1′s pins 1 and 5 causes IC1′s period to approach its full value only gradually, rather than instantly at power-on. Select a resistor-capacitor combination that suits your load. …
Read more original source:
http://www.edn.com/archives/1994/101394/21di7.htm
