This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like those in the Texas TIP series. The load current depends only on the Darlington transistor.
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...
This circuit was found in 80's documentation from Analog Devices. The formulas for calculating the components...
This circuit was found in Siliconix documentation from the 1980s. Common comparators or...