Solid state switch board SS4-48V-PD

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Board Description Specifically designed for 12 Volt to 48 volt DC operation, the solid state switch SS4-48V-PD is a high current solid state relay board equipped with four outputs each one capable of switching up to 10 Amp current. Inputs are optically isolated therefore there is complete separation between inputs, outputs and the circuitry driving the solid state relays. All outputs are Pull Down to Ground and the ground of all outputs is in common and common to the logic ground.
Benefits Wide input voltage range Separate input circuits Switching of up to 40 Amp current all outputs combined Mix and match of floating and common reference inputs Compact size Battery inversion protected
Typical applications Automotive Lamp, alarm, sound drive Emergency switch Battery power main switch Motor direction control Electric brake
Main parameters Vcc = +12 Volt to +48 Volt Input Voltage = - 48 to + 48 Volt Load Output Current = 10 Amp/each

Absolute Maximum Ratings of the Solid State Switch SS4-48V-PD

Operating parameters of the Solid State Switch SS4-48V-PD

NOTE 1 : Input high current increases with the high input voltage applied.

Application Information

Inputs

The solid state SS4-48V-PD board has opto-insulated inputs so it can be used:

 With all inputs loops separate and independent from each other.
 With all input loops sharing connection – 1 as an independent common reference.
 With all input loops sharing a common ground reference.
 With any mix of separate loops and common loops.

The input voltage is considered logic High if higher than 3.5 Volt and logic Low if lower than 1.0 Volt. Negative input voltages are acceptable up to –48 Volt and considered logic Low. Positive input voltages between 1.0 and 3.5 Volt must to be avoided, since they cannot be interpreted neither High nor Low.

In order to enhance noise immunity, each input loop has a resistance of 20 k Ohm, so the input drive needs to be able to supply the relevant input current (0.1 to 2 milliAmp according to the value of the input voltage).

A High input will turn on the relevant output; a LED will visually indicate it by lighting if the output is OFF and darkening if the output is ON.

Outputs

The solid state switch board SS40-48V-PD has four output LEDs; the LEDs light when the load is turned ON and become dark when the load is switched OFF.

The solid state SS4-48V-PD board has two protections:

 A diode in parallel to the load to prevent over-voltage in case of inductive load.
 A short circuit protection that floats the output should a short across the load be detected.

A separate LED will light indicating that the short circuit protection has been triggered on a specific output.
Once the short circuit protection has triggered, the output stays OFF until the short has been removed and the board has been reset.

The board can be reset by:
- grounding the enable terminal, in which case all outputs are switched OFF until the Enable terminal has been left open again

or

- switching Low the corresponding input, in which case only the corresponding output is switched OFF (the corresponding LED turns ON).

Vcc connection

The Vcc input is protected by a diode against wrong battery connection (inverted battery connection); it provides power to the logic section. Do not use this connection to power the loads; the 33 Ohm series resistor will prevent the load current from flowing. See Figure 1 to see how to feed the loads.

Figure 1 - 4 Channels solide state relay board connection

External connections

The schematic shows the connection of the solid state board to the external world. Please note:

 Only one Vbb is shown but it is possible to connected each load to its own power supply of different voltage as long as they all share the common ground.

 The Vcc is shown separate but it can be replaced by anyone of the Vbb’s. Use the lowest voltage one. If using Vbb to power the terminal Vcc, connect the negative pole of Vbb to both GROUND terminals, since ground current is the
highest being the sum of all load currents.

 As a safety precaution, all loads are OFF when the board is initially powered (all short circuit LED’s are ON and all the Load LED’s are ON) . Cycle the Enable switch to deactivate the short circuit protection.

 In normal operation the Enable switch is open and the enable terminal is left floating. The enable switch can be used to set all outputs OFF or to reset after a short has been detected.

Mechanical

Dimensions: 4 x 3 inches /10 x 7.5 millimeters Weight: 0.5 lbs / 220 grams

Ordering instructions

Part number: SS4-48V-PD