This TTL delay circuit has long delay times which can be determined by R1 and C1. The base is in common TTL and Maxim's MAX907.
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...
An integrated circuit 741 (operational amplifier is the basis of this voltage indicator, which can also...
This transistorized voltage converter is one of the oldest that we find in technical publications. It...