[Q] Car stereo at home wiring.

[ramziukas]

Hello i want to ask, how properly connect car stereo at home. I have pc PSU 12v 15amps and router power supply 12v 1amp. When i connect pc PSU directly to car stereo it works, but if turn off power car stereo loose presets and memory. Can i connect router power supply at the same time to keep memory while main Psu is turned off?

 

[Martaine2005]

Hello,
What car stereo is it? Model?
The memory may have a 5v rail. So the constant 5v on the psu could be used. And the 12v still be turned off by it's own switch.

Martin

 

[ramziukas]

Model is: panasonic cq-c1415n
I want turn off pc psu before night, because cooler makes noises.

 

[Martaine2005]

Yes, I understand why you want it off.

Does your psu have a constant 5v?

 

[ramziukas]

Pc psu have 5v, 12v and 3,3v, but if turn off no voltages left. Other router psu is only 12v dc. Also found repair manual for CQ-C1465N but i believe its same pcb layout as my stereo. http://www.filedropper.com/panasoniccq-c1465n

 

[davenn]

Pc psu have 5v, 12v and 3,3v, but if turn off no voltages left. Other router psu is only 12v dc. Also found repair manual for CQ-C1465N but i believe its same pcb layout as my stereo. http://www.filedropper.com/panasoniccq-c1465n

you need a permanent 12V connection
12V comes into the unit via 2 cables ACC ( accessories switch) on the car ignition and direct from the battery
The direct from the battery supplies the main "grunt" current for the stereo's amplifier and also keeps the memories
The 12V via the ACC supplies the power to switch the stereo between running and standby


Dave

 

[Martaine2005]

AH well, if your psu has not got a constant 5v supply, then my idea wont work.
It may be safer to get another psu that has a constant 5v.

Martin

 

[davenn]

AH well, if your psu has not got a constant 5v supply, then my idea wont work.
It may be safer to get another psu that has a constant 5v.

Martin

read my last post, Martin

 

[Martaine2005]

We posted together....I see it!!

Martin

 

[ramziukas]

you need a permanent 12V connection...

Dave

Thanks very much for your time and answering my question. To bad i dont want to use car battery at home. I always thought main all current goes via ACC cable. Maybe i can add small 16v 1000uf capacitor to keep stereo memory?

 

[Martaine2005]

My point was to keep the memory, not power the amp.
The head unit can be turned off by the head units button! But constant power for memory is still there.
So current used is minimal.

Martin

 

[davenn]

yes, I realise you wouldn't want to use a car battery in the house,
the point is you need a second 12V supply

 

[davenn]

I always thought main all current goes via ACC cable.

no, cuz that goes via the ignition switch in the car which doesn't have the current carrying capacity for hi power loads
That is why there is a MAIN connection direct to the battery for the heavy load

No a 1000 uF cap wont do it

 

[Martaine2005]

The simple solution then is.....
psu yellow to radio ACC,
psu yellow with diode to constant 12v.
Router adapter positive with diode to constant 12v.

Turn on psu, Turn off router adaptor and turn radio on!!
To power down, turn radio off, turn router adaptor on and turn psu off!!

Martin

 

[ramziukas]

Can i connect like this? What type diodes use to hold 15A max current?

 

[Martaine2005]

Pretty much like that.
I doubt the stereo will draw more than 2 or 3 amps. So 5 amp diodes should be more than enough.
Forget the 15 amps, that's the max the psu can supply.
Just make sure the diodes are before your red circle joint.
This also assumes no external amps are used.

Although I know this will work as I have explained above, if you damge the stereo, don't come crying!!
This is not the correct way of using a car stereo or ATX PSU.

Martin

 

[ramziukas]

This is only reason why i try to connect Atx psu is i bought stereo for 8euros. I think to add this diode: 1.5KE15A
Could you show in my picture where to add diode please?

 

[Martaine2005]

I don't know what that page says..
But Diode like this.

 

[ramziukas]

Can i pick this one single polarity diode? http://www.st.com/web/en/resource/technical/document/datasheet/CD00000663.pdf
'cuz in my country your suggested diode cost 3-5euros 1pcs.

 

[Martaine2005]

I would think the uni-directional would be the one.
If you're having trouble, buy a bridge rectifier and use that.

Martin