This power source was found in a 1968 Electronics World. The transistors are from that time. The current of each output is limited by the transformer.
This circuit is from Motorola technical documentation from the 70s, but it can be easily assembled...
The circuit shown in the figure is based on the ST Microelectronics TDEO0160 (www.st.com) and...
We found this circuit in a 1985 documentation. The 4-LED bargraph is excited by an input voltage. The...