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View Full Version : whats wrong with my relay motor driver



samurai_01
03-11-2009, 11:07 PM
i made a relay based motor driver with 2n2222 as switching transistor. the uc used was ATmega32. as the sensors were sensing white line, the output given was a high (about 4.5v as i remember) but as they sensed black they responded a low(0.3- 0.6V appprox) but the relays still gave me the same tripping sound which one gets on connecting the vcc and ground of a relay.
the motors did not run but they would sometime run on such a low switching voltage.
why are relays switching even when uc is giving a low???
Is it that ATMEGA32 never gives a perfect 0 volt low or is it n the connections or the base switching resistor value has to be changed( i employed 'Transistor as switch' theory, hope you understand)

avinash_g
03-12-2009, 08:39 AM
Pls post a schematic
:D