The LM337 is a Variable Negative Voltage Regulator that can output voltage from -1.25V to -37V with a maximum output current of -1.5A.
LM337 Pin Configuration
Pin Number
The NTE960 is a 5V Voltage regulator IC with a maximum output current of upto 1A. It requires no external components and has in-built short-circuit and thermal overload protection.
The TL431 is a regulator diode whose output voltage can be programmed by changing the value of resistors connected to it. It acts almost like a Zener diode except for that the voltage rating of this IC is programmable.
The HLK-PM01 is a small size low cost AC to DC converter which can take in 110V/220V AC at 50/60 Hz and give 5V 3W output. The module is can be used in designs which run on 5V and needs to be powered form the AC mains.
A Metal Oxide Varistor (MOV) is a protection component used in power supply circuits that is powered directly from AC mains. It is used to protect the circuit from high voltage spikes by varying its resistance.
6N139 is an optocoupler IC designed for isolating primary circuit and secondary circuit electrically but the pair of LED and photodiode - Darlington setup forms the triggering mechanism between the two sides.