齐纳二极管

• 齊(equal; level; even (like barley sprouts growing uniformly))ASSOCIATIVE

Stalks of grain growing in a straight line symbolize evenness and orderliness.

• 二(number two; two horizontal strokes)ASSOCIATIVE

Two parallel horizontal strokes symbolize the number two.

• 木(tree; wood)RADICAL
• 及(reach; attain; catch up)PHONO-SEMANTIC

An extreme point is the uttermost end of a wooden pole, where a hand just barely reaches.

• ⺮(bamboo)RADICAL
• 官(official; manage)PHONO-SEMANTIC

A bamboo tube is managed by officials, so 管 means both tube and to manage.