Is there a circuit that can energize a coil on 110v, and to keep coil de energized on 220v.

[Brad Hruska]

Hello everyone I need help building an automatic switcher that can handle 10A@ 110v, 5A@ 240v.
I have a need to be able to connect 1 cord to a wall outlet that can be either 110v or 240v and to switch a relay tripping a 110v/240v switch on a 12v power source. Let me explain more I have a power inverter 12.5A/dc on the inverter there is a switch for using 110v or 220v. I have replaced the switch with a 240v relay so that when 240v power is introduced it energizes the relay and connects the NO contacts for 240v. when the coil is off it is connected to the NC contacts with 110v.

My concern is that with the contacts closed in the 110v position, when I apply 240v to switch on the coil and close the contacts to the 240v position, that, that millisecond of 240 applied to the 110 contacts will burn out the components of this ac/dc inverter


Is there any circuit that can be built to do this, 110v out turns energizes a relay coil, and 240 does not energize a relay coil.
Remember that the unit must have only one cable in using both 220v and 110v, to the circuit turning on a relay coil with 110v, and keeping the relay off with 220vView attachment 119471
Is there any way to make this circuit as described? I could us a 110v relay then connecting the 220v to the NC but would need to prevent 220v going to the relay coil to prevent switching.

 

[Brad Hruska]

I am basicly trying to make a switched mode power supply that can send out 12.5a @12v. I can not seem to find one that has that many amps but automaticly detects incoming voltage and switches from 220v to 110v and vice versa.

 

[(*steve*)]

Get one that will operate from 95 to 265V. There not that uncommon.

 

[Brad Hruska]

This is what I am trying to do I think but it must be able to handle 110-220v in to trip the relay circuit

 

[Brad Hruska]

Get one that will operate from 95 to 265V. There not that uncommon.

Steve, the ones I am finding are huge! I need something that handles 10-12.5a Do you have a recommendation for one, the smaller the better.

 

[davenn]

Steve, the ones I am finding are huge!

what ? physically huge ? 12.5A is a lot of juice and requires a significant PSU

the one I regularly use measures 199mm x 99mm x 50mm

you are not likely to find something much smaller than that

 

[Brad Hruska]

what ? physically huge ? 12.5A is a lot of juice and requires a significant PSU

the one I regularly use measures 199mm x 99mm x 50mm

you are not likely to find something much smaller than that

Steve, can you give me a link, to what we are talking about, If we are talking about a relay that is physically massive, if we are talking about a power supply unit then that is fine, I am using a PSU like this one,
there is a physical switch on it to change it from 110 to 220v I have removed the switch and want to connect it to a relay, so when I plug it in it switches automatically from 220v to 110v and vice versa

 

[duke37]

Can you use an AC relay that will only pull in above say 150V. If the relay is a bit too sensitive, then a series resistance could be used.

A diddy DC relay could be used with a suitable supply added. They come in all sizes fromTO5 upwards. It will need to be a fair size to accommodate decent sized contacts.

 

[Pyramid]

Steve, the ones I am finding are huge! I need something that handles 10-12.5a Do you have a recommendation for one, the smaller the better.

MeanWell LRS-150F-12 159 x 97 x 30mm.

 

[duke37]

I have some 230V AC relays
OMRON MK2P or NOSLO, 32 * 32 * 48mm plus international octal contact pins, length 14mm.

I also have some similar naked ex equipment relays which are slightly smaller without their coats.

They all pull in and drop out at 130V AC, 50Hz. A series resistor will increase this voltage to a suitable level.The coil resistance is 7k5Ω so something less than this would be suitable.
Use the change over contacts to select the input you want. You do not need a relay that will pull in at the low voltage and drop out at the higher voltage.

 

[davenn]

Steve, can you give me a link, to what we are talking about, If we are talking about a relay that is physically massive, if we are talking about a power supply unit then that is fine

he's talking abt a PSU .... probably the same as what you showed and I commented on

and @Pyramid has given another example

there is a physical switch on it to change it from 110 to 220v I have removed the switch and want to connect it to a relay, so when I plug it in it switches automatically from 220v to 110v and vice versa

the one I commented on doesn't need a switch

 

[Brad Hruska]

he's talking abt a PSU .... probably the same as what you showed and I commented on

and @Pyramid has given another example



the one I commented on doesn't need a switch

Unfortunatly the one I have is the one with the switch, the country where I am current living does not have the one you mentioned pyramid,

 

[Brad Hruska]

I have some 230V AC relays
OMRON MK2P or NOSLO, 32 * 32 * 48mm plus international octal contact pins, length 14mm.

I also have some similar naked ex equipment relays which are slightly smaller without their coats.

They all pull in and drop out at 130V AC, 50Hz. A series resistor will increase this voltage to a suitable level.The coil resistance is 7k5Ω so something less than this would be suitable.
Use the change over contacts to select the input you want. You do not need a relay that will pull in at the low voltage and drop out at the higher voltage.

Duke I have (2) different 240v relays one is a tosun MK2PN-I and the other is a Omron MY2-GS would either of these work to do what we are discussing? and how do I set it up? I currently have the Omron MY2-gs wired to the power supply, 110v NC, and 220v NO but like I said before I am concerned with the way I have it wired up now, that for that millisecond, durning the switch, it will burn the 110v system.

What you are discussing sounds like it might work, Wouldn't I need the coil to trip at 110v NO and cut off at 220v NC, this way by default the system is on 220v if a 110v was introduced it would not burn the power supply. I think we are on the same page but I am not certain.

Duke can you send me a schematic and parts as to how to do this, I am a visual person.

 

[duke37]

The voltage at which the change over occurs should be a little above110V.
A delay on powering the PSU can be generated with a NYC thermister allowing the relay to get there first. I have just bought some 10Ω 2A thermisters but have not yet played with them.

I cannot do a schematic at the moment. Will have to get my tackle working soon.
Time for bed

 

[(*steve*)]

Relays are pretty slow. Also those switches are not designed to be switched when the power is on.

I would suggest that you risk a very large bang when the relay is operated.

I'm very surprised that there is nobody in the United States that has the items you're looking for.

 

[davenn]

the country where I am current living does not have the one you mentioned pyramid,

well if the country you live in is as indicated by the flag below your avatar
then there are many suitable supplies .... you just haven't bothered to look

here is just one of dozens of examples
http://www.mouser.com/ProductDetail...VrH5rwl1kAh%2bNcTzcLhQZSZYqIFhhLJDSM88hgdeg==

 

[Brad Hruska]

well if the country you live in is as indicated by the flag below your avatar
then there are many suitable supplies .... you just haven't bothered to look

here is just one of dozens of examples
http://www.mouser.com/ProductDetail/Mean-Well/EPS-120-12/?qs=sGAEpiMZZMs2%2bVrH5rwl1kAh%2bNcTzcLhQZSZYqIFhhLJDSM88hgdeg==

I am American, born and raised, hence the flag, just cause you see a flag doesn't mean that is where the person is living, I have been an expat for 15 years. I am currently living in Taiwan. but they don't have any automatic systems here.

Also many say 85-265v and higher but if you carefully most require them to be either mechanically switched, or hard wired to a designated power supply, i.e to get 220v it must be wired to 220v or to get 110 must be hardwired to 110v.

So using what I have how do I make it work. please remember my background is not in electronics, and I am probably old enough to be your father 87 years young. I am trying my hardest to understand this without a completed diagram that I can see and copy.

 

[Brad Hruska]

Relays are pretty slow. Also those switches are not designed to be switched when the power is on.

I would suggest that you risk a very large bang when the relay is operated.

I'm very surprised that there is nobody in the United States that has the items you're looking for.

Born and raised in the states, but that does not mean that's where I am, I have been an expat for 15 years, and only get back to the states once every 2 years.

 

[(*steve*)]

BANG <-- that's the bit you ignored.

If it is 85-265V then you don't have to switch it.

I think that attempting to switch the voltage while the power supply is on is dangerous and should be abandoned as an idea.

 

[Brad Hruska]

BANG <-- that's the bit you ignored.

If it is 85-265V then you don't have to switch it.

I think that attempting to switch the voltage while the power supply is on is dangerous and should be abandoned as an idea.

Steve I did not ignore it, I would love to get one that does this automatically, however I do not have access to this type here, I have access to the one with a switch. thus How do I get this to work? I can not abandon the idea because it is do able I have seen it a few times many years ago. on the old technology, in the 50's for the military they did the same thing on their equipment so it can use either 110 or 220v.