Solenoid Valve Relay Selection

Question

Problem: Solenoid Valve Relay Selection. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

A solenoid valve is an electrically controlled mechanical valve used in fluid/gas systems. The controller energizes the relay to open or close the valve. The relay isolates the controller from the 24V valve circuit.

Since the valve draws only 1.2A, a ≥3A contact rating gives adequate margin. The valve is a 24VDC inductive load, so a flyback diode across the valve is also recommended.

Required: General Purpose · 12VDC coil · SPST-NO or SPDT · ≥3A contacts · 24VDC rated · Non Latching · Through Hole

2. How to Find It on DigiKey

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) → 3A or higher
Coil Type → Non Latching
Mounting Type → Through Hole
Part Status → Active

Tip: Solenoid valves are inductive loads. Always add a flyback diode across the valve terminals to protect the relay contacts from voltage spikes when the valve de-energizes.

3. Key Specifications & What They Mean

Specification	Required	Why
Coil Voltage	12VDC	Matches controller driver supply.
Contact Form	SPST-NO or SPDT	Only NO switching needed.
Contact Current	≥3A	Valve draws 1.2A; margin for DC arcing.
Switching Voltage	24VDC rated	Must handle 24V DC load voltage.
Coil Type	Non Latching	Standard energize/de-energize control.
Mounting	Through Hole, PC Pin	Standard PCB mount.
Temp Range	−40°C to +85°C	Industrial conditions.
Safety Approval	cURus or equiv.	Product certification.

4. Selecting a Safe, Production-Ready Part

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

5. Filtered DigiKey Link

➡ View Matching Parts — 12VDC Coil, SPST-NO/SPDT, ≥3A, DC Rated, Through Hole

56. Solenoid Valve Relay Selection