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

Momentary ground deactivation with a 12V signal


Post ReplyPost New Topic
< Prev Topic Next Topic >
167mph 
Member - Posts: 6
Member spacespace
Joined: July 05, 2016
Location: California, United States
Posted: August 28, 2016 at 12:03 PM / IP Logged Link to Post Post Reply Quote 167mph
I need to solve a peculiar problem that I hope one of you can help with.
I need to be able to disconnect a constant ground possibly using a relay for less than 1/2 a second using a 12V trigger that stays active for more than 1/2 a second.
Thank you in advance.
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August 08, 2012
Posted: August 28, 2016 at 3:35 PM / IP Logged Link to Post Post Reply Quote lurch228
How much more of a Time are we talking about for the 12v?
If less than a second this should work with one change connect ground to 87a instead of 87. If time is still too long then use smaller Capaictor to shorten the time.
Momentary ground deactivation with a 12V signal - Last Post -- posted image.
167mph 
Member - Posts: 6
Member spacespace
Joined: July 05, 2016
Location: California, United States
Posted: August 28, 2016 at 6:59 PM / IP Logged Link to Post Post Reply Quote 167mph
I'll have to time to 12v feed. I'm pretty sure it stays active for more than a few seconds.
I saw this schematic in the library but I need to make sure the ground is constant. Will moving the ground from 87 to 87a correct this? The 12v feed needs to be the only way the ground is momentarily disrupted for less than 1/2 second for me to get the correct setting. If the ground is disrupted for longer than 1/2 a second the setting will change to a function that I do not need. What size capacitor do you recommend?
Thanks again.
167mph 
Member - Posts: 6
Member spacespace
Joined: July 05, 2016
Location: California, United States
Posted: August 28, 2016 at 7:10 PM / IP Logged Link to Post Post Reply Quote 167mph
Also, what wattage should the resistor be?
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August 08, 2012
Posted: August 28, 2016 at 8:31 PM / IP Logged Link to Post Post Reply Quote lurch228
1/4 watt is fine for relay usage. Start with the listed size capacitor and test it.
If you have to get a few seconds of off time from pulse you will have to play around with a higher resistance to slow down the discharge of the cap to allow the 12v to turn off or you will get a cycle on and off of the relay..
If you understand that the flow to charge the cap is turning on the relay and the flow stops when the cap is fully charged turning the relay off. and the resistor is bleeding off the charge at a given rate. Then increasing the resistance or lowering the leak will charge it a little bit faster and keep it charged longer before turning the relay coil back on.
167mph 
Member - Posts: 6
Member spacespace
Joined: July 05, 2016
Location: California, United States
Posted: September 03, 2016 at 3:57 PM / IP Logged Link to Post Post Reply Quote 167mph
Got it figured out. Thanks again.
lurch228 
Silver - Posts: 1,338
Silver spacespace
Joined: August 08, 2012
Posted: September 03, 2016 at 4:22 PM / IP Logged Link to Post Post Reply Quote lurch228
No problem.

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, March 28, 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