Using a Motorola MC1684 integrated circuit this 1968 amplifier provides 1 W to a 8 ohm load. The response ranges from 20 to 20 000 Hz and the distortion is only 1% at 1 kHz.
Found in old American documentation, this circuit can divide the frequency of a signal by 2 or 3...
The transistors of this timing circuit may be more modern types such as BC548 and BC558. The...
An OR gate can be improvised using NAND gates of a 4001 as shown here. The diodes are...