The HW-040 Rotary Encoder Module is a device that generates an electrical signal based on how much the rotary input device (knob) is rotated and the direction it is rotating
The YX850 Power Failure Automatic Switching Standby Battery Lithium Battery Module DC5V-48V Emergency Converter. It is an automatic switching module. When the battery is dead or there is a problem with the battery, it is powered by the power supply.
The BD244C, BD-244, 244 is a 6A, 100V 65W PNP Bipolar Power Transistor is designed for use in general purpose amplifier and switching applications. BD243B, BD243C (NPN); BD244B, BD244C (PNP) are complementary devices.
This is Boost Module With Digital Display which is a high-performance step-up switching current module. The XL6009 DC-DC 4.5-32V to 5V-35V XL6009 Boost Step-up Module Adjustable Digital Voltmeter.
The ESP-01 Breakout Adapter for ESP8266 serial to Wi-Fi transceiver module. Since the ESP-01 pinout is not breadboard friendly and unlabeled, this makes it inconvenient for rapid prototyping.
The 2SC828 is an NPN, Silicon-based AF Amplifier Transistor that is mainly used in AF based audio equipment for amplification and switching. It has a Collector-Emitter Voltage of 25 Vdc with a Collector-Base voltage of 25 Vdc.