the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

Trigger A Relay With Ground


Post ReplyPost New Topic
< Prev Topic Next Topic >
goremanx 
Member - Posts: 3
Member spacespace
Joined: April 14, 2017
Location: Vermont, United States
Posted: April 14, 2017 at 9:26 AM / IP Logged Link to Post Post Reply Quote goremanx
I need to trigger a relay with a ground signal. I've hooked up one end of the relay's coil to a power source, and the other end to my parking brake switch (which provides a ground when engaged). But when the coil closes the switch in the relay, it sends 12v down into the parking brake circuit and makes it hot, which I do not want.
Is there such a thing as a relay that will take a ground as a trigger for the coil, without subsequently making that ground hot? I assume it would be an electronic relay with some kind of logic built-in as opposed to a dumb mechanical Bosch relay.
Twelvoltz 
Platinum - Posts: 2,384
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: March 24, 2005
Location: New Jersey, United States
Posted: April 15, 2017 at 7:12 PM / IP Logged Link to Post Post Reply Quote Twelvoltz
Assuming I am reading this correctly you want to prevent +12V from passing through the coil into the wire proving ground from the parking brake? A simple diode will do the trick.
Installer, IT support, and FFL. I need less hobbies.
goremanx 
Member - Posts: 3
Member spacespace
Joined: April 14, 2017
Location: Vermont, United States
Posted: April 15, 2017 at 7:18 PM / IP Logged Link to Post Post Reply Quote goremanx
I thought of that, but wouldn't a diode also prevent the dash cluster from seeing the ground when the parking brake is engaged?
I'm actually kinda confused about how the parking brake switch works in the first place. When the brake is on, the switch is closed to ground. But no actual current goes through that circuit, it's either grounded or it's not and that's how the gauge cluster knows whether to turn the parking brake light on. How is the cluster detecting a ground when no current is flowing through it? And would a diode mask the ground? It's baffling...
Twelvoltz 
Platinum - Posts: 2,384
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: March 24, 2005
Location: New Jersey, United States
Posted: April 15, 2017 at 7:40 PM / IP Logged Link to Post Post Reply Quote Twelvoltz
You do not insert the diode into the vehicle's wire. You are tapping into the vehicle's wire to activate the relay. The diode is inserted into the wire you are using to activate the relay.
goremanx 
Member - Posts: 3
Member spacespace
Joined: April 14, 2017
Location: Vermont, United States
Posted: April 15, 2017 at 8:50 PM / IP Logged Link to Post Post Reply Quote goremanx
I'm confused... if I put a diode on my relay's circuit, how will the coil of the relay ever complete its circuit and energize?

If you wish to post a reply to this topic, you must first login.
If you are not already registered, you must first register.

  Printable version Printable version Post ReplyPost New Topic
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 Follow the12volt.com on Facebook
Thursday, October 31, 2024 • Copyright © 1999-2024 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
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.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer