This circuit was found in a 73 amateur radio magazine from the 90s. An LED extends the scale from 0 to 5 V to 10 to 15 V in this bargraph circuit. Other zener values can be used.
This circuit of old American documentation (1965) can be applied to any transistor. | Clique na...
This interesting automotive alarm was found in a 90's Popular Electronics. The circuit uses...
This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and...