What usually causes relay chatter?

Relay chatter is typically caused by low voltage conditions. When the voltage supplied to a relay coil is insufficient, the relay may not operate smoothly and instead rapidly switch between on and off states. This oscillation occurs because the relay does not receive enough energy to maintain a steady position, leading it to intermittently drop out and then re-engage as the voltage fluctuates around the activation threshold.

In contrast, high voltage may cause overheating or damage without necessarily producing chatter. An open circuit would prevent the relay from receiving any voltage, hence it would not chatter, but simply remain off. Additionally, mechanical fatigue typically results from prolonged use and does not directly cause chatter; instead, it may lead to failure of the relay over time. Understanding the effects of voltage on relay operation is crucial for diagnosing and troubleshooting relay issues effectively.