schmitt trigger switch..need help

[enzo1]

hi. i need to ask any guys out there.

let's put it this way..i need to construct a circuit with only one BJT, one OPAMP and a single power supply where this schmitt trigger will then detect input signal between range 4V-8V and it will be used to control a relay via a transistor which operate as a switch...

anyone have the idea?please help me..i'm kind of new in this electronic devices..

 

[ante1]

Hi enzo,

Welcome to this forum.

Here is a good description : http://www.ibiblio.org/obp/books/socratic/output/opamp4.pdf
This is in German I hope it make sense to you. http://www.elektronik-kompendium.de/public/schaerer/opaschm.htm
This can be helpful : http://www.elektronik-kompendium.de/public/schaerer/opaschm.htm

 

[enzo1]

thank's a lot..