Adding relay for Power On - How to do it?

I have been told that I need to add a relay for powering on my amps (3), headunit and WS-420. If I don't I will get an annoying POP sound when I turn everything one. Indeed, I do get the POP when everything is powered up.

So, how do I do this? What size relay do I need? What does the wiring schematic look like?

Any help would be much appreciated.

You could grab a soundstream power plant. It works as a relay, as well as power/ground/remote distribution block.

But a relay would probably be cheap. I don't know how to do it, sorry!

Go to page 31 in the pdf

http://www.dlcparts.com/images/BoschGuide.pdf

A relay is NOT what you need. You will still the pop with a relay because it is turning on all the devices at the same time.

The issue lies with your amps your using, they must not have "soft" turn on where it mutes the input untill the amp is turned on and ready to go.

Some older amps don't have soft turn on and you get the pop because the turn on output is being fed into the amps when they all power on together.

To eliminate it you can buy devices which basically add a delay to the amp turn on so they turn on a few seconds after the head unit and stop the pop.

I'm using 2 year old Kicker KX series amps; KX840.4 for tower speakers, KX650.4 for boat speakers and KX600.1 for sub. I don't know if they have a "soft" turn on. I was told by the place that is going to install my WS-420 and tune my system that I needed a relay. I just added the KX650.4 at the end of last season and did not get to use it much. Prior to adding that amp, I never got the "pop" with just 2 amps.

Well you would most likely need a relay as well, since the deck can only turn on a few things with its limited current output on the amp turn on wire.

A relay is needed if your putting more than 2 devices on generally, but a relay is not needed for the "pop" associated.

This is what you need along with the relay.

http://www.logjamelectronics.com/pieeisps.html

As for relay wiring its dead simple.

A relay is just a mechanical switch, activated when voltage is applied to a wound coil of wire, producing a magnetic field, and moving a metal bar towards a contact creating a loop for the current to flow in.

You just need 4 wires, 2 for the coil (to cause the magnetic effect), and 2 for the switch side (which go to NO and C on the relay).

Run a small 500ma fuse between the output on the deck, and the relay coil side, then the other side of the coil to the ground in the boat. Test that by turning the deck on and off to make sure the relay is clicking. If it is your good to go, and just need to run another fuse to the C side of the relay, and run the NO side to all the amps in the system, or to the pop eliminator first, then the amps.

Matt -

How many of those Amp Trigger Delays do I need? One for each amp and one for the WS-420?

Thanks for the help

1 should be fine, you can use the output from the trigger to go into the relay that will power the amp. Its just adding a delay to the amp turn on.

What HU are you running?
Tom, if it's new your more than likely don't need a relay.

Sam -

I am running a Pioneer Premier DEH-M860MP with 6.5V preamp outputs. It is probably 3 years old.

You can build an amp trigger delay with radio shack drawer parts for under $3. All you need is a diode and a capacitor. The below works for power up too.

# Relay Pop

Relay turn-off pop is caused by components in the system turning off before the amplifier completely shuts off. In most cases, the component will be an EQ or signal processor. Usually adding a little turn-off delay to the offending processor can fix the problem. This allows the processor to turn off after the amplifier, preventing the pop. Many components have this feature built in, and it is adjustable. Check the manual to see if your component has this feature available. If not, you can build your own delay circuit with a diode and a capacitor. Add a 1N4004 diode in series with the processor's turn-on lead, striped side toward the unit. Then add a capacitor in parallel, the positive side of the cap connected to the striped side of the diode, the negative side of the cap to car chassis ground (not to the body of the radio or processor chassis). Experimenting with the capacitor value will give you just the right amount of delay before the EQ shuts off. You don't want the delay very long, just long enough to make sure the amp is off before the EQ powers down. Usually 220 - 1000uF is about right. Make sure that the cap is a polarized electrolytic, 16V or higher.

(Message edited by olSkoolTige on May 20, 2008)

TDOE relay: Time Delay On Energization

Otherwise known as a solid state timer:
http://www.ia.omron.com/data_pdf/data_sheet/h3fa_dsheet_csm89.pdf

You shoud also be able to do it with a 555 timer, I believe there is a circuit in the Radio Shack Engineer's mini-notebook?

geek out!