This circuit is from a 1966 publication. The frequency depends on the capacitors and on R1 which can have values between 47k and 2.2 M typically. The supply voltage can be between 200 and 300 V.
This circuit makes use of a transconductance operational amplifier from the 90s. Formula for the...
This linear scale circuit can use the current scale of a multimeter instead of the 50 uA...
This circuit divides the grid 60 Hz frequency to obtain 20 Hz to drive mechanical watches used at...