hi, iv been assigned to give a breif description of how the DC motor speed controller circuit below works. i understand some of the circuit but some parts baffle me, i dont suppose anyone would be kind enough to have a look at the circuit and tell would they? id appreciate it a lot
http://img175.exs.cx/img175/2246/dcmotorcontroller8bm.jpg
http://img175.exs.cx/img175/2246/dcmotorcontroller8bm.jpg