• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

12v dc Relay problem.

Status
Not open for further replies.

scoosh

New Member
hi there, got a problem,:confused: i have got a 12v 15amp max rated dc relay, connected directly to a 12v supply with a 15 amp load.

but now i want to add in an extra 10 amp load on top( total 25amp)
problem - the relay wont switch this extra current? is there a way i can get round this without replaceing the original 15amp relay?

would adding a 12 volt relay 25 amp relay into the circuit after the 15amp relay, solve the problem?

thankyou in advance:)
 

Chippie

Member
[qoute...is there a way i can get round this without replaceing the original 15amp relay? ]


Just change the relay for the 25 amp one....Nothing is added, nothing is taken away
 
Last edited:

mneary

New Member
is there a way i can get round this without replaceing the original 15amp relay?

would adding a 12 volt relay 25 amp relay into the circuit after the 15amp relay, solve the problem?
I gather that the original relay isn't socketed or there isn't a compatible 25A relay that fits into the socket. This would be easiest, but apparently this isn't an option.

Yes, you can either put a 12V 25A relay after the 15A Relay and transfer the entire load to the new relay, or you could put in any relay greater than 10A and connect just the new 10A load to it.
 
Last edited:

BrownOut

Banned
What chippie said

I don't know what it means to put a 25 amp relay after the 15 amp one, but that doesn't sound right. Just replace the 15 amp relay with the 25 amp one.
 

scoosh

New Member
thanks for the reply.
if i put a 12V 25A relay after the 15A Relay and transfer the entire load through the new relay, would that work? it means that 25amp is going to be going through the 15 amp relay before it reaches the load???

would a 12v dc 25 amp automotive relay SPDT do the job?


quote : Just replace the 15 amp relay with the 25 amp one.

i cant touch that side of things:(, but yeh that would be the easiest option.
 

KMoffett

Well-Known Member
I think the idea was to add a 12V/25A relay, then have the existing 12v/15A relay switch the 12v/25A's coil. The 12v/25A's contacts carry the 25A load.

I think.

Ken
 

Boncuk

New Member
Why don't you just parallel the 15A relay (coil) with the 10A relay and connect the 10A load to the new relay?
 

Willbe

New Member
Carrying a heavy current is easier than switching it so switch the lower current relay on first.

Or you could parallel the relays by adding a short piece of wire in series with each relay's contact such that the resistance of the two wires is (each) >5x the closed contact resistance.
 

adaminc

New Member
So Scoosh, what did you do? I have a similar problem, except instead of mechanical relays, solid state relays. I am switching a 600W HPS Lamp and would like it controlled from 5V, and I have two 240VAC/5A SSRs (5V control), would I be able to put them in parallel to lower the risk of one of them burning out?
 
Last edited:

nonkannan

New Member
Hai i have a problem to contact the 12vdc relay. If the load is connected the relay contacts are continuously "ON" & OFF" like clap sound. Pls solve my problem. what is the error in the connections.

Thank u in advance
By kannan.E
 

colin55

Well-Known Member
1. Remove the two 15 amp wires from the relay.
2. Connect one lead of the coil of your new 25A relay to the positive of the car battery.
3. Connect the other lead of the coil to one of the terminals that you have just removed a 15A lead from.
4. Connect the other terminal of the 15A relay to the chassis of the car.
5. Now connect the 15A wires (that you have just removed) to two terminals of the 25A relay and also connect the two wires of the 10A load to the same two terminals.
But you must make sure that when you connect the 10A wires to the terminals, that nothing happens until the relay is energised. In other words, flick the wire onto the relay connection to make sure that no sparks are produced when either/both leads are connected (touched).
 
Last edited:
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top