75th anniversary of the transistor

[ppppenguin]

He also patented the "electrolytic condenser" based on oxide films in 1931.

Electrolytic capacitors existed before then: https://en.wikipedia.org/wiki/Electrolyt...or#History
The wiki article doesn't even mention Lilienthal, suggesting that his invention wasn't in the mainstream of capacitor development. To be fair to Lilienthal, his work has been much overlooked and patent office examination is often not as thorough as it might be.