how to turn a robot left and right?

[nithin kamath]

i am designing a robot using DTMF decoder concept, wherein i will get 4 bit output from the decoder IC which i am going to use to control the robot's moving directions... i cannot use microcontrollers for any purpose..... I am using Two DC motors for two wheels of the robot... and am using a relay to control forward and reverse movement of Robot(by changing direction of rotation of DC motor)....

How can i turn the robot to left and right direction..??? what mechanism i should use...???

Thanks in Advance..

With Regards,
Nithin Kamath

 

[chuckey]

if you use one bit for the Rh motor and one bit for the Lh motor. Then putting one bit on will cause the motor on that side to switch on and the robot will turn away from that side, if both bits are present then the robot should run straight. If you switch these bits on/off at a fast rate then you should get a proportional steering and acceleration.
Frank

 

[nithin kamath]

ok i got it....

now i have another problem.. i am using relay for reversing the direction of motor, the problem is: two terminals in the relay are 'Normally Closed' , that means the dc motor should be always running in atleast one direction....

Then, How can i stop the robot...??? The robot should move only when i press corresponding buttons (2 for FRONT, 8 for BACK, 4 for LEFT, 6 for right, and 5 for STOP)....

 

[chuckey]

The easy answer is that you need a second relay that is actuated when either the "front" or "back" signals are sent, that puts the supply through to the reversing relay.
Frank