Secondly when switching a relay you must have a free-wheel diode across the relay coil, as in this tutorial: So you need to measure the resistance of the relay coil and figure out the current it needs (I = V/R). This means the coil will be powerful and take a lot of current - but I can't find any proper data for it. I am stupid.įirstly the RF6105-12V-C relay seems to be a high power contactor, switching 150A. The relay is controlling a 12v linear actuator. I want the relay to engage when the pin d1 goes high. The relay engages when I get 0v or ground going to the point that the 'collector' is going to in the diagram. Did I wire them up correctly? Is my resistor too large/small? I assume the transistors went bad or I shorted them out when mounting it.

I have confirmed that the relays are still good, but I can't get it to work with the transistors. I mounted the actuator and it stopped working. I was able to engage the linear actuator via 3.3v from wemos board - transistor - relay several times without any problems. I had two of the transistors with a 2.1K resistor switching two separate relays and it worked. I didn't have any TIP120's on hand, so yesterday I thought I would try the 2n2222 to do the exact same thing. I did this same exact thing on another project, but I used a TIP120 transistor with a 2.1K resistor and arduino uno to do the switching, and it is still in use now. I am trying to switch a rf6105-12v-c (what I am calling a relay?) with a 2n2222 transistor. I have read many threads about using transistors to switch relays of larger voltages on with microcontrollers, but most of them end without a solution, or I am not smart enough to understand the responses given.