relay circuit

[itzme]

Hi all,
I would like your opinion on something. Im using a 16F877A to control the switching of a 5V relay. However the relay could not be activated directly. Ive seen on websites that a transistor can be used. What about mosfet? what are the difference between the transistor and the mosfet?

 

[killivolt]

Hi all,
I would like your opinion on something. Im using a 16F877A to control the switching of a 5V relay. However the relay could not be activated directly. Ive seen on websites that a transistor can be used. What about mosfet? what are the difference between the transistor and the mosfet?

You'll have a better chance of getting some answerer's if you have a diagram and an explanation of what your trying to attempt.

Is this a school project an experiment an Idea what is this. How does it relate to your trigger input Computer, Switch etc.

Provide more information.

kv

 

[itzme]

http://www.rentron.com/PicBasic/relay-circuit.gif

this is the link to the circuit im thinking of using, however the the control would be from my PIC. oh it's for my school project
thanks for the advice though

 

[crutschow]

Hi all,
I would like your opinion on something. Im using a 16F877A to control the switching of a 5V relay. However the relay could not be activated directly. Ive seen on websites that a transistor can be used. What about mosfet? what are the difference between the transistor and the mosfet?

A mosfet is a transistor (metal–oxide–semiconductor field-effect transistor). Another, not so common FET, is a JFET (Junction-FET) which are usually only used in small-signal amplifiers, not switches. The more common discrete transistor is a bipolar transistor. The are all used to amplify a signal (transform a small signal into a larger signal).

A mosfet transistor is a voltage controlled device. The amount of voltage on the gate determines the amount of current that flows between the source and drain terminals. Typically it takes about 10V gate-to-source to fully turn on a mosfet, when used as a switch. The transistors come in N-Channel versions (plus voltage on gate and drain) and P-Channel versions (minus voltage on gate and drain).

A bipolar transistor is a current operated device. The amount of base current determines the amount of current that flows between the collector and emitter. The base-emitter junction looks like a silicon diode with an "on" voltage of about 0.7V, thus you need a resistor in series with the base to limit the current. To completely turn on a bipolar transistor as a switch, the base-emitter current should be about 1/10 of the collector-emitter current. Bipolar transistors come in NPN versions (plus voltage on base and collector) and PNP versions (minus voltage on base and collector).

 

[armyrule]

can samebody show me how connection of dc motor control using 2 relay (fwd n bwd) and program using EASY68k?