The Viessman DPDT Relay is a two-pack of monostable double-pole, double-throw relays. The relays have no limit switch, nevertheless they can be driven with steady continuous current. The control takes place by negative switch impulses responding to steady continuous current, AC voltage or digital current. Due to internal electronics the relay is noiseless even by connection to digital circuits or pulsed signals. The relay is particularly suitable for the semaphore home signal item-No. 769-4702 for train control and for item-No. 769-5280 for frog polarization. Relay power input is approximately 2 x 14 mA by 16 V. Power consumption: Maximum 2 A for each changeover contact.