What was the primary initial obstacle that delayed the widespread adoption of Spira's dimmer technology?

Answer

The need for standardization, requiring specific dimmers for specific bulb types/wattages

For decades after the patent, homeowners had to buy a dimmer specifically designed for the exact wattage and bulb type they were using, preventing it from becoming a generic appliance.

What was the primary initial obstacle that delayed the widespread adoption of Spira's dimmer technology?
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