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3950_0 DC Solid State Relay - 30V 50A, 3950


The 3950 DC Solid State Relay can be used to switch loads of up to 50A at 30VDC using the digital output from a 1012 - PhidgetInterfaceKit 0/16/16.

Package includes:

  • A Protective Relay Cover
  • A Heat Transfer Pad
  • A Diode

The Relay comes with an optional protective cover to protect people from touching the exposed high power wires, and a diode to protect your SSR from harmful transients.

All wires connect to this relay by screw terminals.

If you are switching a high power load or find the relay is getting hot, please consider a heat sink. Heat sinks 3955 and 3956 are designed for use with this relay.

Have a look at the relay's characteristic curve in the Data Sheet to decide if you need a heat sink. Without a heat sink, the maximum current that can be handled by this relay is 18A up to an ambient temperature of 40°C.

In order to be able to switch currents of up to 80A, you have to use the 3955 - Heat Sink 

This relay connects to the 1012 - PhidgetInterfaceKit 0/16/16.
Just connect the positive control terminal of the SSR to the +5V terminal on the 1012, and connect the negative terminal to an open collector digital output on the 1012.


Electrical Properties

Relay Output Type MOSFET
Isolation Method Photoelectric
Dielectric Strength 2.5 kV AC
Control Voltage Min 3 V DC
Control Voltage Max 32 V DC
Load Voltage Max (DC) 30 V DC
Load Current Min 20 mA
Load Current Max (DC) 18 A
Load Current Max (With 3955 Heatsink) 50 A
Load Current Max (With 3956 Heatsink) 50 A
Load Surge Current 120 A
Turn-on Time Max 1 ms
Turn-off Time Max 0.5 ms

Physical Properties

Length 58 mm
Width 45 mm
Height 25 mm
Operating Temperature Min -30 °C
Operating Temperature Max 80 °C

Other Properties

Manufacturer Part Number HFS33/D-30D50M