This simple indicator circuit was found in a documentation from the 90s. Trimpots can have values between 2k and 10k, a series resistor is recommended to limit the current to the minimum setting.
The Texas Instruments LM5178 Buck-boost controller is capable of operating in the 4.2 to 55 V (60...
This circuit changes the wave shape of a square signal according the values of C1 and R1. Other...
This RCA circuit has current limitation. The circuit is from an ancient American documentation making...