@All Relays are cheap solutions for reversible motor control...however seems redundant if you use a tip120 to switch on another switch...why not cut the relay out and just use a tip120? They may be "old" but they work. Keep it simple...

@thetechguru There is a problem with this thinking. Why could a 1.5v AA battery turn it on and off with no problem, but the 3v ez-b can't?

My test shows that when the ez-b is set on, the port reads 3.3v. Off, 0.0v. When attached to the relay, it is 3.3v set on, and then 0.85v off...

Why is there suddenly a voltage on the signal pin? In this scenario, the ez-bs signal pin turns into a switch of its own allowing the voltage that is coming in to flow through it. Moving the plug to a different port stops this until it is triggered with the digital control again.

Wow. Simply grounding the signal of the relay to the power source triggers it. Isnt that lovely. So it needs a switch to trigger a switch.

That's why I M pretty sure pull-down resistor is the solution. It pulls a floating signal down to 0 volts. Wish I knew more about electronics so I could explain it better. I am just repeaing what I have heard. If they weren't busy moving offices Jeremie or DJ could explain.

Alan

This may help? https://synthiam.com/Community/Questions/8808

I'm not sure where the resistor would be, or what the value should be. I think following this would be safe? Or no?

The resistor in this would be 10k.

My current wiring is as follows.

If we connect the signal to gnd, it goes high and activates the relay, so the resistor can't go to gnd, right?

MazeHorizonTech,

Can you post a pick/url of your Relay ?