This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the hard-to-obtain component of our day. It is for reference only.
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
This circuit is from the Analog Devices component datasheet. In it we have the way to obtain a low...
Found in a Philips documentation from the 90s, this circuit uses transistors from that time....