enzo

thank's a lot..

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..