Cannot get 30A single channel relay to work

Other Hardware General Electronics
1

i am using the following relay in the below URL. i am trying to get it to work but it does not seem to be switching. i get the red LED come on which shows it is supposed to be running but it doesn't actually do any switching on. originally i just had a multimeter hooked up to the normally open terminals and had the multimeter set to continuity test and was hoping to hear it beep when the relay closed but that never happened, despite the red LED coming on. then i went and chopped up a lamp, cut 1 of the 2 wires coming out of the wall, tinned both sides of the cut and put them into the 2 relay terminals for common and normally open, still nothing, just the red LED and no switching the light on\off.

following configuration:
active HIGH
normally open
5V input
250VAC 10A, 120VAC 10A

any help? could i have just received a bad relay module?

2

Always show us a good schematic of your proposed circuit.

Show us a good image of your ‘actual’ wiring.

3

Looks like your power the relay with 12 volts, but control it with 5 volts? Is that what you tried?

4

Sorry about that. i'm not sure of how to do it properly on here.

i took a picture of it and will describe it in words.

smallest, top left module is an RTC module
largest is the arduino uno r3
medium module on far right is the relay
small bread board

RTC module is connected to

  • arduino SCL, SDA, GND
  • bread board +5VDC which is split from +5VDC from arduino to bread board

relay is connected to

  • arduino: GND, output port 8
  • bread board: +5VDC which is split from +5VDC from arduino to bread board
  • split 1 of 2 wires from a lamp plugged into the wall where each side of the split goes into the common (middle terminal) and NO terminal of relay

signal-2023-04-15-203932
signal-2023-04-15-2039321920×1446 288 KB

5

ahh crap i just noticed it was 12VDC control not 5VDC! i feel stupid

when i was buying it i could've sworn i clicked the 5VDC option (he has many choices)

6

Yes, you are trying to pick the 12 relay coil with 5v from the Arduino.

BTW

Relay coils should have an external power supply.

Do you have a 12v DC power supply and a 2N2222 transistor ?

7

unfortunately i don't :frowning:

i am going to return this relay module and buy the one i intended to buy -- the 5VDC control version

given the photo and my wiring description, that should work as i intend\expected this one to work, correct?

8

this is the one i am going to use instead:

9

Remember to use an external 5v power supply to power the relay coil, not the Arduino 5v pin.

10

i have this

but it is only 9V

11

If you buy a 5v relay coil, it needs 5v.

12

i just assumed the 5V output from the arduino would suffice since all it was doing is switching

13

The 12V relay module may still work with 9V.

14

it doesn't say what tolerances it has

15

Then there's only one (other) way to find out, eh?

16

Lol that's true. i'm not sure how i can connect it to the 9VDC though considering it's a barrel connector. any suggestions?

17

Hack the connector / lead - assuming you don't have a mating jack for such a thing.
Or, hackier still, you could use an alligator clip for the outer conductor and improvise a pin for the inner conductor.

18

Check not only coil voltage but also the required current

19

so out of curiosity, what is the max current output of the 5VDC output pin on the board?

20

so the current relay i was using, according to this guy's testing, the 5VDC pulls ~170mA

Screenshot 2023-04-15 213852
Screenshot 2023-04-15 213852973×529 130 KB