so you can take any npn transistor, emitter to gnd, collector through your = load to vcc 3-30v, and base over a resistor to the pic output. the value of the resistor is about: (vcc=5Fpic - 0.7v) / 0.11a *=20 hfe=5Fof=5Fthe=5Ftransistor / 2. a resistor of about 10k between the transistor's emitter and base is=20 recommended to avoid problem's on pic startup, as long as the pic pin is=20 configured as input. if you don't know 'hfe=5Fof=5Fthe=5Ftransistor', take 100 for a 'bc' type a= nd 30=20 for a 'bd' type. the division by 2 is to make shure that base current is enough. if you take an optocoupler, limit the led current to about 10ma (serial=20 resistor of: (vcc=5Fpic -1.8) / 0.01) and connect the optocoupler's emitter to the power transistor's base and=20 the coupler's collector to the power transistor's collector. the coupler's base is unconnected. a resistor of about 10k is required between the power transistor's base=20 and emitter to make shure that it will open. make shure that the coupler is able to transfer the collector current, the = base of the power transistor needs (or you will need an additional stage). tino =D6mer Yalhi Gesendet von: pic microcontroller discussion list 12.06.03 12:11 Bitte antworten an pic microcontroller discussion list =20 An: PICLIST@MITVMA.MIT.EDU Kopie:=20 Thema: Re: Antwort: [EE]: Transistor / Optocoupler I forgot mention, the transistor will need to work with 3V and the output=20 will be able to handle 3 - 30V and 110mA. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics