Historical clue formulations

• Circuit board device — 2025-01-26
• Semiconductor device — 2023-11-22
• A.C. converter — 2023-10-20
• LED component? — 2022-11-12
• Part of a crystal radio kit — 2020-01-22
• Semiconductor device with two terminals — 2018-04-23
• Cellphone component — 2018-03-02
• Current director — 2017-09-22
• Certain vacuum tube — 2017-02-19
• Current path? — 2015-11-21
• Certain vacuum tube — 2014-12-08
• Electronics component — 2014-07-18
• Part of LED — 2014-02-19
• Electron tube — 2012-04-23
• L.E.D. part — 2010-06-01
• Part of L.E.D. — 2010-02-07
• Electron tube with two elements — 2009-06-23
• Device also called a rectifier — 2008-11-20
• Electron tube — 2005-06-15
• Part of L.E.D. — 2005-02-27
• Crystal set part — 2004-04-11
• Electron tube — 2004-03-29
• Part of LED — 2002-03-19
• Electronic gate — 2000-06-22
• Semiconductor, e.g. — 1999-07-20
• Part of LED — 1998-06-19
• Fleming valve — 1998-03-07
• Electron tube — 1998-02-11
• Electron tube type — 1996-06-09
• Semiconductor device — 1996-04-21
• Electron tube — 1995-06-01
• Electron tube — 1995-04-19
• Radio part — 1994-11-28
• Digital clock's light emitter — 1994-02-04
• Electron tube — 1994-01-26