5v songle relay welds

Other Hardware General Electronics
1

hello, i have some srd-05vdc songle 5v relays and i have 3x 13W led light bulbs betwen COM-NO contacts. after few on-off switches the relays contacts weld together and the relay doesn't turn off anymore only by tapping it . the board is placed on a ceiling in a box so they are facing down. my questions are;

  • how can i decrease the inrush current of the leds to not damage the relay
  • what does a snubber do, and is it placed on the 230v ac side in parallel?
  • do u recommend some relays that work well with switching led lights from relpol/finder or some type of white light led bulbs that are better
    images (1)

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2

It is often suggested here that those relays are not up to their specifications.

I have not tried them in serious use myself, so can't say conclusively.

I would however suspect that these lights have a large capacitor across their input (bridge). "Dimmable" lights do not have such a (large) capacitor.

3

You must have taken the relays apart, just like I did to find they are really junk. Some welded, some had insulating particles between the contacts. The contacts are round so misalignment doesn't matter. Real relays have either flat or slightly convex contacts.
Since you are only working with DC, use MOSFETS instead of relays for your control. Be sure they can be fully switched on by the 5 volts from your Arduino.

4

i am working with 230vAC not dc, i am thinking of replacing them with relpol 5v relays

5

Omron

1 Like
6

Oh, sorry, I was referring to the above statement in your initial post.
I see no mention that the LED light were AC powered.

2 Likes
7

are there spdt that match the pcb layout ?

8

Look around. Check DigiKey.
Omron are reputable, Allen-Bradley, IDEC. Go with legitimate manufacturers, not shadow-market junk.

Relays | Power Relays, Over 2 Amps | DigiKey

9
10

in comparation to sonoff how this type of relays perform ?

11

How do you mean?
Whatever you get - give it a workout on the bench. Don't throw caution to the wind, slap something or other together, and then hurry that out your end-use installation. (That is a recipe for disappointment stew.)

12

what about ssr ?
is there a model that i could use

13

if i replace my songle relay that has 70ohm at 5v with this G5LE-1-E 5VDC OMRON OCB - Releu: electromagnetic | SPDT; Ubobină: 5VDC; Icontacte max: 16A; G5LE-1-E-5 | TME - Componente electronice that has 62.5 ohm , what resistor should i use in order to drive from 3.3v from esp8266 using a transistor ?

14

Probably.

Base resistor? 560 ohms or so.
Any previous experience?

15

with esp no, there should be a minimum value to energize the transistor

16

what about arc protection for the relay contacts ?

17

This is all well-covered ground (how soon they forget).
https://forum.arduino.cc/t/esp8266-long-term-use/946717

With the minimal current you're switching? If there is 'arcing' then it's your wiring and/or your component choice.

18

One of these across the contacts (NO and COM) would probably work wonders.

19

Why do you want SPDT? :astonished:

Welding occurs on contact closure, arc protection not going to help. :grin:

Most likely the inrush current of charging a capacitor in the LED light.

Not inductive, so no more likely to cause arcing than a resistive load.

20

Luckily the OP already knows that tapping the relay can free up welded contacts, so contacts that operate correctly will be protected (both closing and opening) by arc suppression (i.e. MOV). Ahem, note that led drivers have inductive components.