this post was submitted on 23 Jul 2023
10 points (100.0% liked)

Ask Electronics

3283 readers
15 users here now

For questions about component-level electronic circuits, tools and equipment.

Rules

1: Be nice.

2: Be on-topic (eg: Electronic, not electrical).

3: No commercial stuff, buying, selling or valuations.

4: Be safe.


founded 1 year ago
MODERATORS
 

Hello, I have a circuit that will need to return connected hardware to a default state if power is lost. The hardware can handle continuous voltage, so I'm thinking a simple solution would be to use a battery to provide that fallback power source. To avoid draining the battery, I'd like to connect it through a relay on the normally open contact and energize the relay directly from the main power supply on my board.

Do I need to look for anything in particular to make sure the coil on the relay I choose can sustain constant voltage for potentially months at a time without damage? Or, is there another similarly low cost and simple solution you'd recommend?

The circuit runs on 12VDC from a [Mean Well IRM-10-12 (specification), and the relays I have on hand are OMRON G5LE-14-CF 12VDC (specification). I don't see anything on the relay documentation that specifies a maximum duty cycle.

you are viewing a single comment's thread
view the rest of the comments
[โ€“] collegefurtrader@discuss.tchncs.de 2 points 1 year ago (1 children)

Look for the duty cycle on the datasheet. The only relays I can think of with less than 100% duty cycle are automotive starter solenoids.

[โ€“] trafguy@midwest.social 1 points 1 year ago

Thanks, that's good to know! The datasheet doesn't seem to include the word "duty" anywhere, so I think that must have been omitted. Ostensibly that means the maximum duty cycle is unlimited, but I don't have enough experience here to say that with any confidence.