sadono, Can you please describe what "real" series mode surge protection is?
The picture of the Furman unit here: https://www.furmanpower.com/series-multi-stage-protection-smp on the left (from the large inductor and over) seems to match what is described/drawn in the SurgeX patents I linked to from the 80’s. On the right appears to be some traditional MOVs, and probably some voltage detection to turn on/off the relay on the right side. The additional use of the MOVs is a good thing and probably makes the circuit on the left perform better.
The picture of the Furman unit here: https://www.furmanpower.com/series-multi-stage-protection-smp on the left (from the large inductor and over) seems to match what is described/drawn in the SurgeX patents I linked to from the 80’s. On the right appears to be some traditional MOVs, and probably some voltage detection to turn on/off the relay on the right side. The additional use of the MOVs is a good thing and probably makes the circuit on the left perform better.
sadono91 posts11-05-2019 11:18pm
This is not true! The part of SMP that is series mode surge technology is always on. However, this section is more limited in its capabilities with let-through voltages, compared to real series mode surge technology. The MOVs and EVS (Extreme Voltage Shutdown), other parts that makeup SMP (Series MULTI-STAGE Protection), have a delay before kicking in.