DC output solid state relay

solid state relay for dc switching

The diode is required to prevent EMF problems from inductive loads. Almost all loads are inductive so it recommended that you install the diode as shown above. Please install a fast recovery diode that has a PIV rating greater than the line voltage VDC. A suitable diode is available for purchase on the HDD product page. The HDD product is capable of switching the + OR -, which some people might call "high side switching" vs "low side switching".

You can quickly test a HDD solid state relay by using a standard 9 volt battery as the control input. Note the power supply + (terminal 2) and - (terminal 1) locations. If you mis-wire the power supply connections, the solid state relay will always appear ON.

solid state relay for dc switching

The diode has the stripe on the cathode side.


solid state relay for dc loads