It uses the tri-state switch to control speed, direction, and braking.
Schottky output diodes are used that match the current and voltage for your motors.
The only ‘real’ difference compared with the 1 amp circuit is that we using an L298 rather than one of the L293 series. The L298 lends itself to mounting a heatsink, due to the higher current, but is a bit of a swine to solder onto strip board or matrix board and is more designed for PCBs. It uses a ‘Mulitwatt 15’ package – and comes with two strips of pins each using a standard 0.1″ pin separation. But the problem is that the second bank of pins is offset by 0.05″. So if you are using strip/matrix board then you will need to be very carefull when bending one set of pins to fit.
This requires one tri-state switch per motor;
one L298N for every two motors. The L298N costs about $3.57
four diodes per motor at about 50 cents per diode.
So about $11 in total – for driving two motors
Download the schematics here