This circuit was found in a 1991 publication. The transistor can be a general-purpose type.
I found this circuit in an article in a 2003 publication. The circuit is an example of how to...
We find this battery charger in a 90's Hands-On Electronics. The charging current is 2 A and when...
This circuit, from an old ON Semiconductor publication, suggests a shield to excite an LED from an...