This circuit uses components that are still common despite being from 1995 documentation. The circuit can be powered by 6 to 12 V voltages and the speed of the LEDs' sliding effect is set to P1.
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
This configuration is from an old integrated circuit manual. The circuit can be applied to modern...