HexBug Crab Motor Speed

Hi,
Is there any way to put a trimpot in circuit below to control HexBug motor speed ?

http://www.ece.msstate.edu/classes/ece4723/dissect/807648016529/contact.html

Thanks.

 

[Robert Baer]

apogeusistemas@gmail.com wrote:

Hi,
Is there any way to put a trimpot in circuit below to control HexBug motor speed ?

http://www.ece.msstate.edu/classes/ece4723/dissect/807648016529/contact.html

Thanks.

Certainly that schematic is incomplete and inaccurate.
No power supply. Two Q4 devices, no hint as to what J476 might be, etc.