Re: Constants you cannot help but remember

[toma]

Here's some from my EE role:

• The 1% resistor values closest to the 5% resistor series
• The 5% capacitor series
• 2.54
• 3.14159
• 2.71828
• 159kHz ~ 1M Radian/sec, where 1mH = j1k and 1uF = -j1
• Way too many component specifications, such as 2N2222A Beta_min = 100
• An arcane corporate part-numbering scheme that dates back to microfilm and punch cards.

[sleepingsquirrel]

And those with an affinifity for BJT IC design

25ohms (re @ 1mA Ic)
-2mV/C (Vbe tempco)
1.21V (band-gap voltage)
25mV (thermal voltage)
0.35 (converting BW to rise time and back)
99.7% (3 sigma)