please help me with my Relay array
Moderators: jsmcortina, muythaibxr
-
- Helpful MS/Extra'er
- Posts: 121
- Joined: Fri Jan 24, 2014 4:52 pm
- Location: Australia
please help me with my Relay array
Hi Guys, I've just come across something I cant crack on my own, please help!
I am using a single relay on my Fuel pump output to switch a ground that is common to my other accessory relays that I want switched with the F.P. (one of which is the F.P. itself)
with 2 relays on the common ground the array worked fine, but I have recently added 2 more and the relays are now staying on, I have tried disconnecting them and checking resistance, they are all 130-150k then connect 1 at a time, 2 is fine, the third I can JUST feel toggle then number 4 goes "clunk".
Is there for some reason a limit to the amount of relays that can share a ground?
(edit)Actually I should clarify that all the relays do not share a common +12v supply, I just tapped-into a supply and at least one shares the supply for the output with the supply for the relay. Could this be a feedback issue?
So it actually looks more like this... Anyone have some input on this?
thanks in advance!
I am using a single relay on my Fuel pump output to switch a ground that is common to my other accessory relays that I want switched with the F.P. (one of which is the F.P. itself)
with 2 relays on the common ground the array worked fine, but I have recently added 2 more and the relays are now staying on, I have tried disconnecting them and checking resistance, they are all 130-150k then connect 1 at a time, 2 is fine, the third I can JUST feel toggle then number 4 goes "clunk".
Is there for some reason a limit to the amount of relays that can share a ground?
(edit)Actually I should clarify that all the relays do not share a common +12v supply, I just tapped-into a supply and at least one shares the supply for the output with the supply for the relay. Could this be a feedback issue?
So it actually looks more like this... Anyone have some input on this?
thanks in advance!
Last edited by Subaru_EA82_4EAT_AWD on Sun Dec 24, 2017 2:13 am, edited 2 times in total.
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
A little thing I made up... https://youtu.be/PajlPNF5mmQ
Re: please help me with my Relay array
To prevent relays interacting, fit a diode in series with the coil. 1N4001 is a suitable type. If might be possible to buy them with one built in.
BTW, I doubt the coils measure at 140,000 ohms.
BTW, I doubt the coils measure at 140,000 ohms.
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
MS2 V3
EDIS
Tech Edge O2
London UK.
-
- Helpful MS/Extra'er
- Posts: 121
- Joined: Fri Jan 24, 2014 4:52 pm
- Location: Australia
Re: please help me with my Relay array
(edited first post)
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
A little thing I made up... https://youtu.be/PajlPNF5mmQ
-
- Helpful MS/Extra'er
- Posts: 121
- Joined: Fri Jan 24, 2014 4:52 pm
- Location: Australia
Re: please help me with my Relay array
...thanks so, make it more like this? Are the diodes better-off on the ground side or the power side?DaveEFI wrote:To prevent relays interacting, fit a diode in series with the coil. 1N4001 is a suitable type. If might be possible to buy them with one built in.
BTW, I doubt the coils measure at 140,000 ohms.
and yeah, I rechecked and the coils measure around 80ohms
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
A little thing I made up... https://youtu.be/PajlPNF5mmQ
Re: please help me with my Relay array
Yes- that's the way. May not actually need a diode for every coil, but won't do any harm.
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
MS2 V3
EDIS
Tech Edge O2
London UK.
-
- Super MS/Extra'er
- Posts: 1423
- Joined: Mon Oct 17, 2011 7:28 pm
- Location: South Western Ontario
Re: please help me with my Relay array
It sounds like you may have stumbled on creating a latching relay, by connecting the pins in such a way to self trigger, or rather are looped between contacts and coil.
If you could draw a complete diagram of all connections, that would help sort out what's going on.
A test though would be to disconnect the load side of the new relays and make sure that the relays will switch on and off correctly.
It's also possible that you have internally suppressed relays (diodes across the coil internally) that could be causing the issue.
Using a standard Bosch style 30/40 relay you would be able to run about 90 relays off one main control relay. A typical Bosch style draws around 300 mA, and the continuous current capability of the contacts of a typical Bosch style relay is 30A.
If you could draw a complete diagram of all connections, that would help sort out what's going on.
A test though would be to disconnect the load side of the new relays and make sure that the relays will switch on and off correctly.
It's also possible that you have internally suppressed relays (diodes across the coil internally) that could be causing the issue.
Using a standard Bosch style 30/40 relay you would be able to run about 90 relays off one main control relay. A typical Bosch style draws around 300 mA, and the continuous current capability of the contacts of a typical Bosch style relay is 30A.
Last edited by Six_Shooter on Tue Dec 26, 2017 9:25 am, edited 1 time in total.
Tha Toy: 1973 Datsun 240Z Turbocharged, and loads of fun, now MS'd
Tha Otha Toy: 1923 T-bucket Hot Rod, Currently Sniper'd
Tha Daily: 2005 Chevy Blazer
Tha Summer Daily: 1987 Buick Skyhawk hatchback
Tha Long Term Project: 1985 GMC S-10 Jimmy, hasn't been fun for a while
Tha Otha Toy: 1923 T-bucket Hot Rod, Currently Sniper'd
Tha Daily: 2005 Chevy Blazer
Tha Summer Daily: 1987 Buick Skyhawk hatchback
Tha Long Term Project: 1985 GMC S-10 Jimmy, hasn't been fun for a while
Re: please help me with my Relay array
I think you created a loop between a switched 12V and your switched (relay) grounds.
Make sure that the connected grounds of the relay array isn't connected to anything else.
Make sure that the connected grounds of the relay array isn't connected to anything else.