Most Programmable logic Controllers (PLCs) are designed to operate from a 24 VDC power supply. This industry standard ensures that the PLC is compatible with the ecosystem of components found in a typical control panel. However, there are times when a 12 VDC PLC is more convenient such as when an automotive or marine 12 VDC power system is used.
Digikey offers a variety of PLCs that operate at 12 VDC. A representative example is shown in Figure 1. This Siemens LOGO! model 6ED10521MD080BA2 features an integral display and pushbutton interface. It may be used on 12 or 24 VDC systems.
Figure 1: This Siemens LOGO! PLC will operate in a 12 VDC system.
Tech Tip: The supply voltage is generally associated with input voltage. For example, a PLC with a 24 VDC will generally use 24 VDC sensors. Deviation from the 24 VDC industry standard will limit the variety and number of compatible field devices.
How to locate 12 VDC PLCs
The power supply specification is included in DigiKey’s parametric search engine as shown in Figure 2. Like other searches, simply select desired power supply voltage.
Figure 2: The PLC supply voltage specification is included in DigiKey’s parametric search engine.
Best wishes,
APDahlen
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About this author
Aaron Dahlen, LCDR USCG (Ret.), serves as an application engineer at DigiKey. He has a unique electronics and automation foundation built over a 27-year military career as a technician and engineer which was further enhanced by 12 years of teaching (interwoven). With an MSEE degree from Minnesota State University, Mankato, Dahlen has taught in an ABET-accredited EE program, served as the program coordinator for an EET program, and taught component-level repair to military electronics technicians. Dahlen has returned to his Northern Minnesota home and thoroughly enjoys researching and writing articles such as this.
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