This circuit was found in the November 1974 Radio Electronics magazine. The voltage depends on the supply and the timings of R1 and R2 as well as C1 and C2.
This circuit was taken from Maxim documentation from the 1990s. It can be implemented on the basis...
This circuit allows linear brightness control of an LED from an input voltage. The power supply must...
This circuit is from a Hands-On Electronics from 1987, but it can still be easily assembled, as...