Irrigation controllers with enhanced alternating current switching devices

An irrigation controller, comprising:

• a live AC line and an AC common line wherein the live AC line receives an AC power signal, defined across the live AC line and the AC common line, having a voltage usable within the irrigation controller;
• a plurality of AC switching devices coupled with the live AC line, wherein the plurality of AC switching devices are configured to selectively pass the AC power signal to one or more valve solenoids to control irrigation valves such that the one or more valve solenoids are effectively coupled across the live AC line and the AC common line;
• an impedance element coupled serially on the AC common line with the transformer, wherein the impedance element comprises an inductive reactance and a resistive component, and the impedance element is configured to increase overvoltage protection of at least the plurality of AC switching devices increasing an effective voltage tolerance to the overvoltage conditions at the AC switching devices;
• and
• a controller configured to selectively control the plurality of AC switching devices in selectively allowing the AC power signal to pass through one or more of the AC switching devices to power the respective one or more valve solenoids.