I have this relay module : https://www.amazon.co.uk/gp/product/B06XKQQXKW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I want to drive the 8 control pins (driving low at 3.3v) from the ESP32. I believe that each pin needs 70mA according to this datasheet:http://datasheetcafe.databank.netdna-cdn.com/wp-content/uploads/2015/10/SRD-05VDC-SL-C-Datasheet.pdf.
The relay is a SRD-05VDC-SL-C which I believe correlates to a 5v high sensitivity coil. That means each pin will draw 70mA to drive the coil, obviously this is way beyond the spec for the ESP32. Except this relay board is being driven by an optocoupler, so I am not sure if this is the current i am supposed to be looking at.
How can I drive this safely using normal cheap components, as doing so directly from the device would be pushing its current limitations. I understand a NPN transistor will likely be involved, however I am not entirely sure of the safest, best way to proceed. Please help by example of a circuit.