The TPDV1240RG is an electronic part with a Triac, manufactured by STMicroelectronics. It has a reverse breakdown voltage of 1.2 kV, a current rating of 40 A, a gate current no greater than 200 mA, and is in a THT (Through-Hole Technology) package. The device operates as an Alternistor, a high-voltage tube, with a TOP3 index code.