12VDC Power and Cooling HAT for Raspberry Pi — PMD Way
For Raspberry Pi 4, X832 V1.2 12V 3.5 inch SATA HDD Storage Expansion – Geekworm
Amazon.com: UCTRONICS DC 12V Time Delay Relay Module, On Delay and Off Delay for Automobile, Raspberry Pi, Industrial Control, and Other Electronic Projects
Seenov Raspberry Pi 6 Channel 12bit Analog-to-Digital ADC with Input 1V to ± 12V, ADC for Pi or Any WiFi Enabled Device, onboard ESP32C3, Compatible with RPI Models 400 4B 3B+ 3B 2B
Geekworm Raspberry Pi 4 SATA Adapter 3.5", X832 V1.2 12V 3.5 inch SATA HDD Storage Expansion Board for Raspberry Pi 4 Model B Only (Not Include Raspberry Pi&HDD) - Newegg.com
Super capacitor based UPS power for Raspberry Pi and embedded system,7-24v input,5v or 12v output - AliExpress
Powering the Raspberry Pi from the power supply of your 3D printer
BEGINNER] Control 12v fan with raspberry pi, triggered by temperature sensor : r/raspberry_pi