We found this circuit in a Poptronics from 1998. The circuit can be extended to more competitors with another 4011. The power can be made with voltages from 6 to 12 V.
This circuit uses a photo-transistor to trigger a circuit sourcing a square signal for the output. The...
This circuit makes use of an uncommon integrated circuit. It can provide a power of 6 W when...
The circuit is from an 80's publication, but the components are current, only special type diodes...