The SG3524 incorporates on a single monolithic chip all the function required for the construction of regulating power suppies inverters or switching regulators.
They can also be used as the control element for high power output applications.
The SG3524 was designed for switching regulators of either polarity, transformer-coupled dc-to-dc converters, transformerless voltage doublers
and polarity converter applications employing fixed-frequency, pulse-width modulation techniques.
The dual alternating outputs allows either single-ended or push-pull applications.
Each device includes an on-ship reference, error amplifier, programmable oscillator, pulse-steering flip flop, two uncommitted output transistors, a high-gain comparator, and current-limiting and shut-down circuitry.
The chip is new.
Here is the datasheet (PDF)