This post explains for the relay.
The Part Number is A5W-K, A-5W-K.
The function of this semiconductor is DC 5V, Solid State relay.
Manufacturer: Fujitsu Microelectronics
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A5W-K is 5V DC, Solid State Relay. A Solid State Relay (SSR) is an electronic switching device that is used to control electrical loads without the need for mechanical contacts like those found in traditional electromagnetic relays. Instead of using moving parts and physical contacts, SSRs utilize solid-state components like semiconductor devices (usually power transistors) to perform the switching action.
1. Extremely low profile and light weight
(1) Height: 5 mm
(2)Weight: approximately 1.2 g
2. Meet FCC (Part 68) standard
3. Conforms to FCC rules and regulations part 68
(1) Surge strength 1,500 V
4. High reliability—bifurcated contacts
5. Wide operating range
6. DIL pitch terminals
7. Plastic sealed type
8. Latching version available
SSRs find applications in various industries and systems, including industrial automation, HVAC systems, robotics, medical equipment, lighting control, heating systems, and more.