I am shopping for a cheap array of Solid State relays to do some switching in my project.
Arduino pin current
According to this modest data, would my Arduino Nano be able to drive those relay modules directly or would they require additional transistors to reduce the current (sinking our sourcing) through the pins?
Thank you.
Are you wanting input (coil) current or output current? If the latter, it is on th relay or can be found via Google.
The boards appear to have drivers on them so can be switched from the Arduino.
Weedpharma
There is no coil, but "coil current" on this module is 12.5mA vs the 160mA that the circuit consumes with the driver. So Arduino would be able to control this circuit?
A typical technical description that is written by a typical Chinese salesperson for this device (1 relay module):
Description:
5V Omron solid state relay 240V 2A, output with resistive fuse 240V 2A
Size: 243221mm/0.941.250.82”
Input Power: 5V DC (160mA)
Input control signal voltage:
(0-2.5V state low relay OFF)
(3-5V state high relay ON)
Module interface:
Input section:
DC +: positive power supply (by relay voltage power supply)
DC-: connect power negative
CH: relay module signal to trigger the end (high level trigger effective)
Voltage version static current working current trigger voltage trigger current
5V 0mA 12.5mA 3.3-5V 2mA
"Coil" was used as a generic term.
Are you wanting to use the relay that is used on the board but not the board?
The board needs 160mA but I would expect a lot less for the relay on its own.
You can google the relay to find the drive current required.
Weedpharma
You have linked to two different types of relays.
The mechanical ones (cubes) and the solid state ones (flat).
Solid state relays just have an opto LED that can be driven by an Arduino pin (~12mA).
They can only switch mains power loads, e.g. not low voltage DC.
The mechanical relays on the board you have linked have a transistor with base resistor.
I expect the base resistor to be 1k, so drive current for the Arduino pin could be ~4mA.
But mechanical relays also need coil power.
Arduino's 5volt rail can supply the power for maybe two relays (2x ~80mA).
But four relays "on" at the same time (4x 80mA) could overheat the regulator.
Those relay boards have a provision for external relay supply, so a 5volt adapter could solve that problem.
Leo..