We found this configuration in a 1990 Poptronics. The circuit can be powered by voltages between 6 and 15 V, changing the resistors in series with the LED. The frequency is set at R7.
We found this circuit in a 1999 publication. All the components used are still common and the...
This circuit was found in a 1999 English magazine, but can be easily assembled with BC548...
We found this circuit in a 1977 technical documentation. The circuit can use a TIP31 for Q1 and a...