This circuit was found in the October 1987 Radio Electronics magazine. The circuit is a PWM control with a 555. It appears that the 555 is missing a connection that would be pin 4.
This circuit was taken from Maxim documentation from the 90s. The components are from the period....
Here we show how a Constant Current Source can be created in the Multisim Blue using a common BJT...
This circuit has several features, such as timing to activate and deactivate, in addition to a...