R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 02-05-2004, 04:21 PM   #1
Tech Fanatic
 
Cardboard's Avatar
 
Join Date: Feb 2004
Location: Flushing,NYC
Posts: 843
Send a message via AIM to Cardboard
Default Someone good with electronics......help....

I made this cutoff unit to go along with my standard 10 1157 bulb discharger.
http://www.nascart.com/disd.htm
Anyway, while discharging my packs, I have to hold down the switch. I am using all the equipment listed there besides a smaller project box i bought by accident(d'oh! )
Being that I have to sit there holding the switch, it kinda defeats the purpose of this unit. I have tried using a 100,60 and 10 ohm resistor. The 10 ohm resistor worker properly but cutoff at about 7.4v. The 60 cut off a bit higher also but the switch must be held down. The 100 cutoff about right, but I had to hold the switch.
So, here's my question. What did I do wrong? It's a PITA to sit there and push down a small switch .

Also, my first post here.
Greetings.
Cardboard is offline   Reply With Quote
Old 02-05-2004, 04:33 PM   #2
Tech Elite
 
JusBox's Avatar
 
Join Date: Sep 2003
Location: Central VA
Posts: 2,170
Trader Rating: 1 (100%+)
Default

Not really sure but i used to do projects like this and found it was cheaper in the long run to just buy a proper discharger/cutoff unit
JusBox is offline   Reply With Quote
Old 02-05-2004, 05:50 PM   #3
Tech Addict
 
Neil's Avatar
 
Join Date: Oct 2003
Location: me..me..me
Posts: 583
Send a message via MSN to Neil
Default

how many watts is the resistor rated for? You might want to try a bigger resistor. Same ohm value just a higher watt one. Make shure you have the correct relay too. Also look closely at your work. If you have any of the wires reversed it can cause undesired operation. I might be able to tell if you post a pic.

Last edited by Neil; 02-05-2004 at 05:58 PM.
Neil is offline   Reply With Quote
Old 02-05-2004, 07:02 PM   #4
Tech Elite
 
GTO2's Avatar
R/C Tech Charter Subscriber
 
Join Date: Jul 2002
Location: Don't Blink !!
Posts: 2,264
Default

Quote:
Originally posted by Neil
how many watts is the resistor rated for? You might want to try a bigger resistor. Same ohm value just a higher watt one. Make shure you have the correct relay too. Also look closely at your work. If you have any of the wires reversed it can cause undesired operation. I might be able to tell if you post a pic.
Yes, might need to try other relay with wider voltage spec (5-12V) something like that.
GTO2 is offline   Reply With Quote
Old 02-05-2004, 07:51 PM   #5
Tech Fanatic
 
Cardboard's Avatar
 
Join Date: Feb 2004
Location: Flushing,NYC
Posts: 843
Send a message via AIM to Cardboard
Default

Quote:
Originally posted by Neil
how many watts is the resistor rated for? You might want to try a bigger resistor. Same ohm value just a higher watt one. Make shure you have the correct relay too. Also look closely at your work. If you have any of the wires reversed it can cause undesired operation. I might be able to tell if you post a pic.
It's rated for 1/2 watt. Here's the pic of the wiring on the relay. I can't access my ftp, sorry for the dl.
Attached Images
File Type: jpg im005145.jpg (68.2 KB, 88 views)
Cardboard is offline   Reply With Quote
Old 02-05-2004, 08:10 PM   #6
Tech Master
 
Join Date: Aug 2002
Location: Nor-Cal
Posts: 1,853
Trader Rating: 18 (100%+)
Default

Select a different relay. The relay "pull" voltage is probably too high (higher that 5.4v anyway) for this application. When I was building these things I just used a different relay from the same batch and the cutoff worked just fine. It's just production tolerances... some of the Bosch relays I used would work, some wouldn't.

Art
Advil is offline   Reply With Quote
Old 02-05-2004, 08:19 PM   #7
Tech Addict
 
Neil's Avatar
 
Join Date: Oct 2003
Location: me..me..me
Posts: 583
Send a message via MSN to Neil
Default

yea true
Neil is offline   Reply With Quote
Old 02-05-2004, 08:22 PM   #8
Tech Fanatic
 
Cardboard's Avatar
 
Join Date: Feb 2004
Location: Flushing,NYC
Posts: 843
Send a message via AIM to Cardboard
Default

Quote:
Originally posted by Advil
Select a different relay. The relay "pull" voltage is probably too high (higher that 5.4v anyway) for this application. When I was building these things I just used a different relay from the same batch and the cutoff worked just fine. It's just production tolerances... some of the Bosch relays I used would work, some wouldn't.

Art
I think your right.....the radioshack relay pull-in is 6v.....
So should I just head over to radioshack and buy another one? Or a different relay?
Cardboard is offline   Reply With Quote
Old 02-05-2004, 08:33 PM   #9
Tech Initiate
 
Join Date: Nov 2003
Posts: 23
Default

http://www.balakracing.com/autocutoff.htm
This guy says to use a push-on, push-off switch instead of the momentary switch shown on the other site. That will keep the power flowing to the relay without you holding the button down.

I have not tried this thing, so I'm not going to vouch for the accuracy of that idea...

good luck with your project.
Jay
Corruptor is offline   Reply With Quote
Old 02-05-2004, 08:52 PM   #10
Tech Master
 
Join Date: Aug 2002
Location: Nor-Cal
Posts: 1,853
Trader Rating: 18 (100%+)
Default

Hmmmmm, as I remember I was using 12v relays. I can't remember the "name" on the box but they were repackaged/relabled Bosch relays. I think the part # was VF415F11S01. I bought them like this because they were cheaper by the 100.

Best I can do for you...sorry.

Art
Advil is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
competiton electronics stealth 35 bl real good condition DENNIS STORTI R/C Items: For Sale/Trade 10 11-21-2006 01:47 PM
RC12L3 Electronics tires Batteries GOOD COND goneRVing R/C Items: For Sale/Trade 6 11-30-2005 06:49 AM
Good online electronics website bigdog xxx-s Electric On-Road 2 06-20-2005 11:54 AM
Modified Savage 25 for sale/trade for good electronics or RTR tc4 mjs3350 R/C Items: For Sale/Trade 16 06-04-2005 04:20 PM
Misc electronics for sale.(good stuff) INFERN0 R/C Items: For Sale/Trade 7 09-18-2004 01:02 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 11:42 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net