relay driven by microcontroller 89S52

hey guys can ne1 help me?????????
i want to drive a automobile starter relay(12V, 2 ohms, commonly used in 2 wheelers) from 0v 2 its pull in voltage & from 12v to its dropout voltage. using atmel 89S52, pls giv me the solution for this

rahul3dreams said:

hey guys can ne1 help me?????????
i want to drive a automobile starter relay(12V, 2 ohms, commonly used in 2 wheelers) from 0v 2 its pull in voltage & from 12v to its dropout voltage. using atmel 89S52, pls giv me the solution for this

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Try this... standard relay driver circuit for a relay. 2 ohms is a bit low for a relay coil tho', are you sure this is right?

CarlosFandango said:

Try this... standard relay driver circuit for a relay. 2 ohms is a bit low for a relay coil tho', are you sure this is right?

Click to expand...

You didn't read his post accurately - he said 'starter relay' - which is usually called a solenoid, and does take LOT'S of current, so 2 ohms sounds quite plausible.

Nigel Goodwin said:

You didn't read his post accurately - he said 'starter relay' - which is usually called a solenoid, and does take LOT'S of current, so 2 ohms sounds quite plausible.

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Ah, yes of course, I answered in haste. I should have realised that.

Well, in case the original poster reads this... the relay circuit I posted would do it, by using a small relay to control the larger (starter solenoid). Although, I am in general against using a relay to control a relay it's still going to be easier and cheaper that way (probably!).