OK.

When only the Q1 is in place with reversed diode, relay keeps activated all the time.

Now it appears Q1 is defective or installed incorrectly. Should read 3 volts on the Gate and 0 volts on the Drain if good and installed correctly.

 

OK.

Now it appears Q1 is defective or installed incorrectly. Should read 3 volts on the Gate and 0 volts on the Drain if good and installed correctly.

I checked the Q1. As you mentioned there is 3v at Gate and 0v at Drain. These were measured while the diode was in the correct direction. In this setup though I pressed the doorbell button or the wall switch, relay didn’t work. (I have not connected the Q2).

Once the diode was reversed, the relay kept activated continuously and the Q1 Gate and Drain had 0v.

 

Once the diode was reversed, the relay kept activated continuously and the Q1 Gate and Drain had 0v.

I'm not sure what's going on but the circuit works perfectly on my breadboard.
Can you get me some more voltage readings on Q1?

 

I'm not sure what's going on but the circuit works perfectly on my breadboard.
Can you get me some more voltage readings on Q1?

Yes, I’m more than happy to. Please see the attached photos.
If you could share a photo of your breadboard, I’ll try to replicate it to see exactly similar. Then you can easily go through the circuit.

 

Yes, I’m more than happy to. Please see the attached photos.
If you could share a photo of your breadboard, I’ll try to replicate it to see exactly similar. Then you can easily go through the circuit.

Another two photos.

 

I see several voltages that should not be there. Going to have to step back and do this one stage at a time.
Are you sure the jumper on the relay module is set for HIGH?

 

I see several voltages that should not be there. Going to have to step back and do this one stage at a time.
Are you sure the jumper on the relay module is set for HIGH?

Currently I’m using a 5v relay with no jumpers and it’s little different that the schematic diagram posted in post #1.
I hope the current one is by default set for High. Is there any way to check it?

 

Take the wire on the input to the module and connect it to the negative and see if it activates. If it does it set for a LOW trigger.
If it is a LOW trigger the circuit is easily modified for that module.

 

Take the wire on the input to the module and connect it to the negative and see if it activates. If it does it set for a LOW trigger.
If it is a LOW trigger the circuit is easily modified for that module.

Yes. It activates once I connected th IN cable to 5v negative side and keeps inactive for the 5v positive.

 

Will get back to you on this later this afternoon.

 

I am tempted to to send this guy a working assembled circuit just to end this thread.

 

I am tempted to to send this guy a working assembled circuit just to end this thread.

You are most welcome sending me a assembled circuit. And my apologies on the lengthy thread. As you already know I’m not in to electronics in my profession though I’m trying to learn it as I’m fascinated by electronics. So please bear with me.

 

New version using LOW trigger relay module.
Suggest not connecting Q3 until you have Q1 and Q2 circuit working. Work in stages please and report.

 

New version using LOW trigger relay module.
Suggest not connecting Q3 until you have Q1 and Q2 circuit working. Work in stages please and report.

View attachment 298927

Thank you.

Without the Q3, system works perfectly. Once I press the video doorbell button, relay is activated. (Video).

But when the Q3 is inserted, video doorbell button is activated without pressing it. Moreover, the relay is also active even without pressing either buttons.

 

That's because there is voltage on the output of the opto isolator even when the doorbell button is not pressed. I see 3.25 volts in the photo in post #105. Try changing R3 to a 10K resistor.

 

Sound like the problem is that we din’t have the video doorbell button characterized correctly, thus @sghioto cannot test the circuit.

I think this would help:

Measure the voltage across the video doorbell button leads.

Then do the 3 more measurements with 3 different resistors across them, 100, 1K, and 10K. This would help us understand how the button is wired.

 

The video doorbell button is not the problem. It's the opto isolator as previously mentioned.

 

That's because there is voltage on the output of the opto isolator even when the doorbell button is not pressed. I see 3.25 volts in the photo in post #105. Try changing R3 to a 10K resistor.

Once I replace R3 with 10k resistor still the relay keeps activated. Then there is a voltage of 0.86v at the output of the opto isolator.

 

Try a 1K resistor.
Q3 may be bad also as my test show the 2N7000 requires appx 2 volts at the gate for 0 volts at the drain in this application.

 

Try a 1K resistor.

With 1k resistor, video doorbell doesn’t auto activate unless i press it, as expected. But pressing the 230v button doesn’t activate the relay. I measured the voltage of output of the opto isolater and it’s almost 0v with and without pressing the 230v button.