48. DC Motor Relay Selection

The controller needs to turn a 12V DC motor ON and OFF. A relay isolates the motor’s high-current circuit from the low-current controller, and provides a clean mechanical ON/OFF switch.

DC loads are harder on relay contacts than AC loads. AC current crosses zero 100/120 times per second, which helps extinguish the arc when contacts open. DC current has no zero-crossing, so the arc persists longer and erodes contacts faster. This is why adequate current margin is important.

Required: General Purpose · 12VDC coil · SPST-NO or SPDT · ≥5A contacts · DC rated · Non Latching · Through Hole

Go to DigiKey.com → Relays → Power Relays

Apply these filters:

• Coil Voltage → 12VDC
• Contact Form → SPST-NO (1 Form A) or SPDT (1 Form C)
• Contact Rating (Current) → 5A or higher
• Coil Type → Non Latching
• Mounting Type → Through Hole
• Termination Style → PC Pin
• Part Status → Active

Tip:  When checking the datasheet, look for the DC contact rating specifically. Many relays are rated 10A at 250VAC but only 5A or 3A at 30VDC.

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

➡ View Matching Parts — 12VDC Coil, SPST-NO/SPDT, ≥5A, DC Rated, Through Hole