Simple four wheel Robot control circuit on 12V Power supply

This circuit Works for  four 12 volt dc motors .In this cricket.  I gave the two output  terminal for both left and right motors.

For that we have to connect both left motors in parallel and both right motors in parallel.

As shown in fig. S2 and S1 switch is DPDT Rocker type switch .connection is same for left and right so I gave only right one connection. We have to connect parallel connection of right side motors between pin no.6 and pin no.4. of switch. Switch 1 is used for on off for power supply And using the variable resistor you can change the speed of motors.

NOTE: Use sufficiently large het sink else it will burns the transistor .

Here is the view of DPDT Rocker switch with pin number .use this pin number  to further connections

Flowing Diagram shows. How to connect the pins of switch to each other.

Now we have to place this switches side by side on solid surface(right switch at right side and left one is at left side)

HOW IT WILL WORK?

1] When switches are ideal no motion is done..

2] When we press both switches up or forward robot go forward.

3] When we press both at switches or backward robot go backward.

4] But when we have to turn robot towards left side .We have to press only right side forward switch.  

5]And when we have to turn robot towards right side .We have to press only left  side forward switch.  

ENJOYYYYYYYYYYYYYYYY