With the indicated components, this circuit oscillates at 1232 Hz. Consider the tolerance of the components. The circuit is from a 1974 Ferranti transistor manual.
This circuit was obtained from an American publication from the 60's. The transistors are...
This circuit detects light variations using two LDRs as sensors. Operational amplifiers and...
Using the 555 this circuit was found in a Popular Electronics from the 90's. The circuit directly...