This circuit was found in the February 1999 issue of Electronics Now magazine. The circuit consists of a timer that triggers a visual and audible starting device.
This circuit was taken from the 1974 Ferranti transistor manual. Transistors are common types at...
This circuit is suggested by National Semiconductor and makes use of the negative regulator LM2990...
The transistors in the presented circuit can be the BC548 and the filter in front of the...