TeensyDigital
Well-known member
I need to drive a dozen 4A opto relays using the Teensy 4.1. I am trying to figure out if I can drive them directly with the Teensy or if I need a transistor in-between.
The opto relay I am considering is the 4A Omron G3VM-31AR (link below). The spec for this relay says the LED needs a minimum of 1.5v and max of 1.8v. If I use a 200 ohm resistor in line I am at 1.55v and I measure a draw of 7ma on the gpio pin. So, this seems like I am in range, but if I have a dozen of these on at once will I be pulling too much power?
As a test of science, I also hooked the relay up directly without the current limiting resistor -- at 3.3v that relay draws 58ma, overpowering both the Teensy and the relay.
Any thoughts on using this relay in bulk would be appreciated. Also, is there a better opto relay that you would recommend with lower resistance that can still serve up 4A on the output side? I'd prefer not to use a FET, as I need the extra isolation.
Thanks!
OMRON G3VM-31AR: https://www.mouser.com/ProductDetai...5jDk3cUWyAw==&countrycode=US¤cycode=USD
The opto relay I am considering is the 4A Omron G3VM-31AR (link below). The spec for this relay says the LED needs a minimum of 1.5v and max of 1.8v. If I use a 200 ohm resistor in line I am at 1.55v and I measure a draw of 7ma on the gpio pin. So, this seems like I am in range, but if I have a dozen of these on at once will I be pulling too much power?
As a test of science, I also hooked the relay up directly without the current limiting resistor -- at 3.3v that relay draws 58ma, overpowering both the Teensy and the relay.
Any thoughts on using this relay in bulk would be appreciated. Also, is there a better opto relay that you would recommend with lower resistance that can still serve up 4A on the output side? I'd prefer not to use a FET, as I need the extra isolation.
Thanks!
OMRON G3VM-31AR: https://www.mouser.com/ProductDetai...5jDk3cUWyAw==&countrycode=US¤cycode=USD