The two integrated circuits used in this configuration can still be found. The frequencies of the effects are determined by the capacitors, which may have their values changed.
This circuit was obtained in a magazine Hands-On Electronics of June 1987. It is a circuit that...
The purpose of this circuit found in an old Elektor is to light a lower power lamp when the bigger...
Found in a 90s Popular Electronics, this circuit uses two PLL tone recognizers to trigger by touch an...