Christmas lights not receiving power

Hey everyone-

I am trying to power a single string of Christmas lights with the simple blink sketch. I am using a solid state relay, and an Arduino Uno. I tested the solid state relay and christmas lights with a 9v battery, and that worked. I know the blink sketch is uploaded and working corectly because the on board LED for pin 13 is blinking. But the sketch is not working on the christmas lights.

The connections are like this: grnd to input - on the relay; digital pin13 to + on the relay; output + to bare wire on the christmas lights and output - to the other bare end.

So why am I not blinking my lights?
Sorry if this is a painfully obvious thing, and thanks in advance!

What solid state relay? Part number?

Hi,

output + to bare wire on the christmas lights and output - to the other bare end.

Where is the power supply for the lights? Can you post a picture of your project and a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom..... :)

Heya-

The SSR is made by Crouzet. Model M-OAC5-315-ELE-0937.
First photo is solid state relay. (Right)
Second photo is the hand drawn diagram.

Hi, Have you got a DMM to measure the voltage across the input to the SSR when it is supposed to be ON. Also try another output pin with edited sketch.

Tom.... :)

Tried another pin already- no dice! :slightly_frowning_face: I did connect a 9v to the input of the SSR and the lights turned on. What do I check besides?

I apologize for lots of questions that may seem really naive, I'm a newb at electronics. I have a DMM handy. Tested from the pin 13 to the + input on the relay, then from the ground on arduino to the - on the relay. Did not hear a tone. So my issue is where I thought it was- between the arduino and the SSR. How can I fix it?

So many thanks! I appreciate your fast responses. =]

takewing14: I have a DMM handy. Tested from the pin 13 to the + input on the relay, then from the ground on arduino to the - on the relay. Did not hear a tone.

I hope you did that continuity test with the power disconnected. If you connected as you say above, with the DMM on the continuity range, and didn't hear a tone, then your connections are faulty. (Assuming that when you touch the DMM probes together you do hear a tone, that is.)

I think you should post a photo of your setup. Somethin' ain't right.

Hi, Measure the DC voltage across the input to the SSR when it is supposed to be ON. Then check DC voltage between gnd and the arduino output when it is supposed to be ON. They should be the same, if you have 5V out of the arduino, but not at the SSR input then check all your wires and connections.

I agree with OldSteve, its time for a picture of your project.

Tom.... :)

If your Christmas lights are LEDs, there's a chance that their built-in power supply doesn't like being switched on & off quickly.

I would think the default Blink LED sketch at 1 second would be plenty long enough, but if they are LEDs, try something like 10 seconds to see if that's the problem.

Regular-old incandescent lamps can be blinked/flickered at about 100mS (on for 1/10th of a second and off for 1/10th of a second). Any faster than that and they won't go completely on or completely off.

LEDs can switch faster than the eye can see, but sometimes their AC power supply cannot, so you usually switch the DC side. (Your AC solid state relay probably won't work with a DC load.)