what kind of relays do i need?
Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=127340
Printed Date: May 21, 2024 at 4:21 PM
Topic: what kind of relays do i need?
Posted By: electronics1994
Subject: what kind of relays do i need?
Date Posted: May 15, 2011 at 9:34 AM
i have a 96 chevy beretta and i am putting in a second head unit for undisclosed reasons.i want to be able to flip one (toggle) switch to switch between active head units. my car has 12 wires coming from harness. one of them is a constant 12v for memory so i dont need a relay for that i just run it to both the head units(to keep all the settings for both). so now we are down to 11 wires. but i have an amp so i have 5 wires there (remote, and the rca(pos,neg and another pos, neg)) the remote wire i can just connect strait to the 12 acc from the original harness so it turns my amp on when my car turns on, no matter what head unit it active.so thats just 4 wires from my amp, add that to my original 11 and we got 15 wires total. now the part that i need help with. i have no idea what type on relays i need or anything. i know i need a relay that has connections in both the on-off positions so head unit A will be active in the normally off position, while head unit B will be active in the on position. so i know i will need more than one relay because i doubt they make a readily available 16 terminal relay with 32 on- off terminals(guessing 16 because it would be weird if they made odd numbered relays) the relays need to handle amplified signals since each unit has a pre-amp. also gold platted would be nice (at least for the rca's relays)and please correct me if any of my theory is wrong.
Thank you for your time,
kyle
Replies:
Posted By: howie ll
Date Posted: May 15, 2011 at 10:38 AM
3 4 pole changeovers should cover this. Used to do this aftermarket for people who wanted an 8 track to go with the factory radiocassette-40 years ago!
You won't need a switch, the remote amp to trigger the relays
The amp leads can all be commoned (2 out of 1 connectors)
If you do want a switch, you'll need a latching 1pco type
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 15, 2011 at 12:12 PM
howie ll wrote:
3 4 pole changeovers should cover this. Used to do this aftermarket for people who wanted an 8 track to go with the factory radiocassette-40 years ago!
You won't need a switch, the remote amp to trigger the relays
The amp leads can all be commoned (2 out of 1 connectors)
If you do want a switch, you'll need a latching 1pco type
wow, thanks for the fast reply. i dont quite understand the switch part though. how would i switch between the head units? and what is a latching 1pco type?
Posted By: howie ll
Date Posted: May 15, 2011 at 12:18 PM
If you need to ask those questions you can't do it
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 15, 2011 at 12:30 PM
sorry? i'm 17 and in two college electronics classes, i'm not an expert,i'm an amateur. this is the reason i came to the forums, was to ask for help/assistance in this little project and the knowledge i would gain would also be a plus.
well thanks for your help anyways:)
Posted By: the12volt
Date Posted: May 15, 2011 at 12:38 PM
Howie, your first reply is not the easiest to understand. Maybe is has to do with being on a different side of the pond. Regardless, your second reply is of no help at all. -------------  the12volt • Support the12volt.com
Posted By: the12volt
Date Posted: May 15, 2011 at 12:56 PM
electronics1994, if you do not want to use use relays, there are switching units available. In your case you'd need one for speaker level switching and one for source switching.
If you choose to use relays, you do not need to switch power between the head units. You just need to switch the output signals between the two head units to your speakers and amplifer. If your current setup has four speakers plus an amplifer for subs, you could use 11 SPDT relays. 2 for each speaker, one for each amplifer input signal and one for your remote turn on lead to adequately power the other 10 relays. If I get a chance this evening, I'll draw a digram for you. ------------- the12volt • Support the12volt.com
Posted By: electronics1994
Date Posted: May 15, 2011 at 1:09 PM
yes i was thinking about leaving power to both, but i was afraid that my small battery/alternator couldnt keep up with two head units and an amp on top of that. but anyhow, what would be the pros and cons between my relay method and your method? as of preformance, cost, and quality of output?
sorry for all the questions i know you have more important things to do, but i just dont want to do/ buy all this and it doesnt work, or it sounds terrible or god forbid, catch on fire haha
thank you so much for your help,
kyle
Posted By: i am an idiot
Date Posted: May 15, 2011 at 2:30 PM
Do either of the radios have an aux input?
Posted By: electronics1994
Date Posted: May 15, 2011 at 2:52 PM
i am an idiot wrote:
Do either of the radios have an aux input?
both have 3.5mm in the front, one has rca aux in also.
why? haha
Posted By: i am an idiot
Date Posted: May 15, 2011 at 3:06 PM
Go to Radio Shack and purchase an 1/8 inch to RCA adapter, connect it to the output of the secondary radio and to the input of the primary unit. When you want to use the secondary deck simply select aux in on the primary deck and power up and play the secondary unit.
There will be minimal extra current draw from the secondary unit. Maybe 2 amps of current. The main current consumption of a radio is the current needed to drive speakers. The secondary unit will have no speakers connected to it, hence the couple amps of current.
Posted By: electronics1994
Date Posted: May 15, 2011 at 3:28 PM
i am an idiot wrote:
Go to Radio Shack and purchase an 1/8 inch to RCA adapter, connect it to the output of the secondary radio and to the input of the primary unit. When you want to use the secondary deck simply select aux in on the primary deck and power up and play the secondary unit.
There will be minimal extra current draw from the secondary unit. Maybe 2 amps of current. The main current consumption of a radio is the current needed to drive speakers. The secondary unit will have no speakers connected to it, hence the couple amps of current.
okay i see what you mean and how it would help save power but id like to have two fully functional head units, not to have on piggy back off the other. the more i think about im liking the idea of keeping both powered, but flipping a switch to change the outputs between the two. but if my car cant handle that kinda demand im perfectly content to have one work at a time.
im sorry, i know its easier but not really what i was looking for but thanks for your interest in my topic:)
Posted By: howie ll
Date Posted: May 15, 2011 at 4:15 PM
OK, I stand chastened, you shouldn't need a switch for the following reason You will need one standard automotive and two 4PDT relays such as Mouser part #655-PT52AO12B
One radio, your second, is the default, left switched on all the time, as soon as you turn on the original that will come on and turn off the aftermarket, turn it off, back comes the aftermarket
The reason is that you will use the factory amp out (remote switch lead) to also trigger your relays Thus turning on the original radio will switch the speakers and the power to that unit
Here's how-
Normal Bosch style cube relay, ACC from ignition switch to 30
ACC to new radio 87a
ACC to old radio 87
Ground to 85
Join to your amp switch lead from original radio via an inline diode 1N4004 to 86 band, (cathode) and to the amp again towards the amp
Another of the same diode across 86 and 85 with the band (cathode) to 86
Now here's the complicated part, link 86 to both of the four pole relays, ground the other side of both coils
4 speaker plus outputs to 30
From original head unit to 87
New head unit to 87a
Repeat with last relay for speaker minus outputs
85 = coil minus
86 = coil plus
87a = N/Closed
87 = N/Open
30 = Common
Having said all that you will also need shrink sleeving to go over the terminals on the 4PDT relays as insulation the soldering part on those relays will blow your mind it's so boring, the constant 12v+, illumination, grounds etc can also be joined to both, RCA/phono leads also the amp switching lead on the second radio should also have an inline diode as above.
Having done all of this you do realise that Mr. Idiot's last post was a much better idea, assuming you can reach both units
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 15, 2011 at 6:23 PM
okay. you win haha you lost me. i still dont understand how i would manually switch between each radio. and whats with the diodes? also i know that idiots way is super easy but its not what i want and it would double eq the second radio and my second radio is out of reach.
why wont my original set up work? just having relays and one radio is on in the "off" position and the second is on in the "on" position(possibly keeping the remote and acc,constant,ground,illum all hard wired to each radio if it wont use too much power just to have a second powered)
i know im being difficult/newbie, but thanks for everyones help so far:)
im really liking the12volt community
Posted By: howie ll
Date Posted: May 16, 2011 at 2:21 AM
Which is why I made that comment, actually that pompous crap about "undisclosed" location really got to me When your dealing with people like Mr I and myself who install stealthed tracking equipment for a living undisclosed doesn't mean much.
Again with the second head unit on all the time via the ACC, you won't need a switch, the diodes are to protect the output stages of both head units from feedback when the other is on
Your last suggestion will work fine if you're not powering up any speakers, just line outputs to amps. Otherwise do as you suggested and wait for the feedback to blow up your head units, hence isolating or switching relays.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: oldspark
Date Posted: May 16, 2011 at 4:00 AM
Howard!! It was undisclosed reasons - not location.
If you & Mr I are having troubles tapping into echelon let me know and I'll branch my pipe - that's assuming yous lack the quality I enjoy.
(Don't worry - it's still the same virtual wave technology... and still undetected. Don'tcha love fibre-optic technology?!)
And don't give LocDet info...
PS - I should send you that joke about bouncing proxies... it's so last millennium (probably not even 8-bits at that!).
Posted By: howie ll
Date Posted: May 16, 2011 at 4:09 AM
Peter Echelon ONLY listens to the US from here, NSA listens to the UK you listen to NZ (boring), NZ listens to you and the Mossad does the rest of the world
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: oldspark
Date Posted: May 16, 2011 at 5:40 AM
Geez they really don't trust you do they?
I could say it's all Greek to me... but that was local (Simpson) which is may not have been linked in... (NZ don't have Greeks do they? I think NZ got the Scots et al, we got the Poms and the South of Romers.
Meanwhile we still track semi-trailers to our north... maybe even London....
Posted By: howie ll
Date Posted: May 16, 2011 at 5:54 AM
I've done tracker installs where they wanted two in a vehicle but I recently did some work where they wanted three because the drivers were so untrustworthy.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: oldspark
Date Posted: May 16, 2011 at 8:19 AM
Crikey - three >20kW amplifiers in one vehicle!
We prefer to keep ours remote and fixed - mobile stratosphere modeling is just too far over most peoples horizons... er, I mean... heads.
Posted By: electronics1994
Date Posted: May 16, 2011 at 7:23 PM
howie ll wrote:
Which is why I made that comment, actually that pompous crap about "undisclosed" location really got to me When your dealing with people like Mr I and myself who install stealthed tracking equipment for a living undisclosed doesn't mean much.
Again with the second head unit on all the time via the ACC, you won't need a switch, the diodes are to protect the output stages of both head units from feedback when the other is on
Your last suggestion will work fine if you're not powering up any speakers, just line outputs to amps. Otherwise do as you suggested and wait for the feedback to blow up your head units, hence isolating or switching relays.
okay, to clear up the undisclosed blah blah, i just didnt want to go into why i want a second head unit because i see how strict this site is as of topics and where they are posted, also i didnt want to get off topic. but any how, blowing up head units, not okay in my book haha, i see now that there is my way of doing it and there is the right safe way that you know haha. i apologize for my bull-headedness. i see now i came here asking all the wrong questions, so can you tell me everything i will need and how to do it right to avoid any "blowing up" haha
so thanks for your much wanted help:)
Posted By: i am an idiot
Date Posted: May 16, 2011 at 8:40 PM
Why do you insist on having 2 decks? Why is preamp out into Aux in not an option?
Posted By: electronics1994
Date Posted: May 17, 2011 at 4:16 PM
i am an idiot wrote:
Why do you insist on having 2 decks? Why is preamp out into Aux in not an option?
i want two decks because i recently got a $450 deck for free that has a 7" flip up dvd touch screen and it wont fit in where my other deck is. so i am putting the deck in front of the passengers seat in the dash. and me being kinda ocd i dont want a hole where my deck is now so im leaving it in and obviously because i will die trying to reach for the touch screen. but putting the out into the in is an option, its just kinda an inconvience and i thought, if its possible, why not use relays to switch between which ever one that i wanted to have on. also there is a part of me that thinks this stuff is cool and wanted to use it and say look what i can do haha then i get to explain awesome electronics stuff:)
Posted By: howie ll
Date Posted: May 17, 2011 at 4:57 PM
Not electronics at all it's electromechanical.
A) Mr I is as usual quite right, why give yourself all that grief?
B) Why not just remove the old and fit the new?
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: howie ll
Date Posted: May 17, 2011 at 4:59 PM
Just to make myself clear as someone who first started installing audio equipment into cars in 1973:-
There's no such thing as it won't fit!
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 17, 2011 at 5:33 PM
the way my dash is the flip screen doesnt have clearance, and thanks for correcting me btw:)
Posted By: howie ll
Date Posted: May 17, 2011 at 5:54 PM
Make a wood and plastic or fibre glass and plastic spaces, dress it the 2"/50mm forward to allow clearance.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 17, 2011 at 6:04 PM
howie ll wrote:
Make a wood and plastic or fibre glass and plastic spaces, dress it the 2"/50mm forward to allow clearance.
the setup i have now brings the radio out about 2" and it still needs another 2" to clear and then it blocks my air vents and look dumb imo
Posted By: electronics1994
Date Posted: May 20, 2011 at 3:08 PM
okay, i guess im stuck doing idiots way since i cant figure out how to do it the way i wanted safely. so i have one more question b4 im on my way. since im just splicing in the main 4 power wires, acc,grd,illum, mem. do i any diode protection anywhere or what? i just wanna do this right at least.
Posted By: howie ll
Date Posted: May 20, 2011 at 4:48 PM
NO.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 21, 2011 at 9:36 PM
alright. thanks for all your help. and howie idk when or why you started hating me but im sorry.
okay thanks again :)
Posted By: howie ll
Date Posted: May 22, 2011 at 4:07 AM
No hate, I'm more of a grumpy frustrated teacher.  ------------- Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: electronics1994
Date Posted: May 23, 2011 at 8:29 PM
alright i understand haha well thanks again and i bid you all farewell:)
|