We found this circuit in an American documentation from the 1990s. The circuit is based on the LM3909, a low power oscillator from National Semiconductor.
Found in a 1960s Philips documentation, this circuit accepts inputs from 16 to 20 V. The...
This 4-digit counter uses CMOS integrated circuits and is powered by voltages from 6 to 12 V. The...
The voltages in an adjusted range in the trimpots are indicated by 3 LEDs. The LEDs indicate when...