The IRFZ44N is a 55V 49A TO-220 Package MOSFET family of power MOSFETs utilizes proven silicon processes a wide portfolio of devices to support various applications as well as battery powered applications.
The C945 is an age old Japanese Bipolar audio frequency NPN transistor 60V 150mA TO-92 package. It has a decent gain value (hfe) of maximum 700 and is highly linear. Hence it was widely used in amplifier.
The HA17741/PS is an internal phase compensation high-performance operational amplifier, that is appropriate for use in a wide range of applications in the test and control fields chips DIP-8 Pins Package.