R1 may be 10k and R2 100k. The transistor can be the BC548 and instead of the small lamp we can use a series LED with a 1k resistor. D1 is germanium and C1 is 10 nF. C2 can be 47 nF.
This circuit is intended to trigger an alarm when the input voltage exceeds one value and to...
We found this automotive alarm circuit in a 90's Popular Electronics circuit. The circuit emits a...
This frequency divider with SUS was found in General Electric's 1967 documentation. Similar...