Traction converter PTP is designed for speed control of DC traction motors and is applied in rebuilding of tram cars T3 (the product of Czech Socialist Republic).
The converter consists of two independent power units within one single enclosure that supply power to DC motors of two car trucks. Control unit is located in central converter compartment. Power circuits of the trucks function independently of each other, which allows driving the car off to tram depot if equipment of one of the trucks fails.