motor drive

hello,

i am doing a project whose complete details are at:
http://www.geocities.com/tjacodesign/cerberes/cerberes.html

the problem is i am not finding the bd435/436 transistors instead of which can i use a ic(L293D)

my motors are 3-4v normal d.c.motors.

Yes you can use a H-bridge chip as long as your motor does not need more current than the IC is able to supply. The motor will consume more current the faster it goes, the heavier the load it has to drive.

Ivancho