3958_0 - DC Solid State Relay - 120V 75A, 3958

£62.42 £52.02

This SSR switches up to 120VDC / 75A and connects to any device with a digital output.

This relay comes packaged with a heat transfer pad and a 10A02-T diode. Use the heat transfer pad whenever mounting the SSR on a heat sink or metal surface. Use the diode in parallel with your load in order to protect your SSR.


For high current loads, this solid state relay is the way to go. Using the digital outputs from a Phidgets device, you can control the relay to silently switch a DC circuit at 120V/75A or less. There's an indicator LED on the control side of the circuit so you can tell the state of the relay at a glance. 

If your SSR is overheating, you should consider getting a heat sink for safety. See below for a list of compatible heatsinks. This SSR comes with a heat transfer pad that can be placed between the metal base of the SSR and the surface it's mounted to in order to help encourage heat flow. It also comes with a diode that can be used to protect your SSR against back EMF.

Electrical Properties

Isolation Method Photoelectric
Dielectric Strength 2.5 kV AC
Control Voltage Min 3 V DC
Control Voltage Max 32 V DC
Load Voltage Min (DC) 5 V DC
Load Voltage Max (DC) 120 V DC
Load Current Max (DC) 75 A
Load Surge Current 375 A
Turn-on Time Max 2 ms
Turn-off Time Max 2 ms


Physical Properties

Length 57 mm
Width 43 mm
Height 25 mm
Operating Temperature Min -20 °C
Operating Temperature Max 80 °C


Other Properties

Manufacturer Part Number KG1075D