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 simple NiCad battery charger was found in an English documentation. Resistors R2 and R3...
This was a very popular instrument in the workshops of the 60s and 70s. It was a "top of the line"...
We found this circuit in a 1981 publication, when it was still possible to find 22.5 V batteries (used...