negative powered relay

Home / the12volt's Install Bay / Relays / negative powered relay (

Topic Closed)

Welcome Guest :)

Members

< Prev Page < Prev Topic Next Topic >

seeker1

Member - Posts: 24

Joined: December 02, 2007

Location: Washington, United States

Posted: April 08, 2008 at 11:04 PM / IP Logged

Thank you for input.

i an an idiot

Yes there is an antenna lead, but from what I understand it's only hot when the radio is on. Not the cd. This is what i was going to use to switch a relay for the main power for the amps. I have 2 Infinity's 1 ref611a for the sub & ref7541a for the front and rears. Closing in on a 1000 watts with the 2 combined. This rig is for my daughter so I have no doubt she'll be sitting around with just the stereo on. Everything is wired through the remote battery in the trunk just so she can, and not kill the starter. If the antenna wire does not work, going straight to the hot lead (red wire) on the head unit is my backup. I'm just an anal retentive tweaker that wants it my way. Amps on only when the head unit is on.

dualsport

I like your idea of a voltage comparator. Any ideas of where I can go to due some research on them and figure it out?

Seeker1 The anal retentive tweaker

Only the strong survive.

Eat the weak.

i am an idiot

Platinum - Posts: 13,673

This member consistently provides reliable information

Joined: September 21, 2006

Location: Louisiana, United States

Posted: April 08, 2008 at 11:15 PM / IP Logged

In most cases the power antenna wire is only hot when the radio is on. Since this unit has no power amp remote wire, I really think that the power antenna wire will be hot anytime the deck is on, cd, radio, usb, whatever it has. Connect it and try it. Years ago before there was a separate amp turn on wire, the power antenna wire was the amp wire and they were hot anytime the radio was on.

You can't tweak it until it gets in the car.

dualsport

Silver - Posts: 983

Joined: September 27, 2005

Location: United States

Posted: April 09, 2008 at 1:22 AM / IP Logged

Here's a datasheet for a comparator you could look at for ideas-

comparator

If you use the example in Figure 2 for inverting comparator with hysteresis, you could use the output to control a transistor driver to turn on a relay when the Vin input goes above a set threshold. The comparator can only sink a small amount of current, so it won't be able to drive a relay directly.

If you use a current sense resistor for the input signal, you should be able to tweak the resistor values so that it'll turn on when the head unit is powered on. Just use a small enough resistance so it doesn't affect your input power too much, but large enough to get a signal for the comparator to work with.

Here's a link for a nice description of its uses:

comparator info

< Prev Page

Sorry, you can NOT post a reply.
This topic is closed.

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

negative powered relay

Sorry, you can NOT post a reply.This topic is closed.

Sorry, you can NOT post a reply.
This topic is closed.