The ER21A is a small thyratron or gas filled relay.
The cylinder forms one main electrode. Above the glass foot is a substantial ceramic insulator.
The second main electrode is a flat plate with a small rectangular portion pressed out at 90 degrees. This small flap is close to the third element. The trigger electrode is a plain wire that ends a short distance away from the tip of the flap.The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 46 mm tall.Reference: 3002. |
Updated December11, 2013.
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