![External DC12V Power Gem Tester](https://d27wgn5g4t3wja.cloudfront.net/products/82dcf239-9e7d-41b8-8be8-53e465fc4d07/469052.png)
External DC12V Power Gem Tester
Fuzhou Zhongtuo Optoelectronic Co.,Ltd
12V power supplies (or 12VDC power supplies) are one of the most common power supplies in use today. In general, a 12VDC output is obtained from a 120VAC or 240VAC input using a combination of transformers, diodes and transistors.