Check this site out it has a delay turn on circuit and turn off delay that we can use in our setup.
I am working on the best of both worlds, I liked the idea of the delay while I am getting gas or running into a store real fast, but disliked the chances of the the computer hanging and killing my batt.
I am waiting for my 10x10000uf caps, aiming for a delay of about 5-8 min using the diagram previously posted. I will let you know how it goes and have pics for everyone that want to see what it looks like. Thanks everyone for the ideas and diagrams. I have been a longtime lurker and this is my first post
Yeah, I'd be interested to see how it goes. Mine didnt work.Originally Posted by Heywood
7+ minute power off delay without risk of computer hang killing battery!
The box is complete and maintains power to my inverter for just over 7 minutes. I set laptop to shut down after 5 so there is more then enough time for it to shut down before power is lost. I made this box do three things.
First- power maintainer- using a relay, 10 - 10,000 25v capacitors I purchased on EBay (the caps at radio shack are too expensive and 35v too big), and the diagram that patO posted on the 2nd page of this thread and the other radio shack goodies
Second- power on- I have a wake-on-lan connector on my Think-pad docking station. By shorting the two outside terminals, the computer turns on. I used another relay that gets its power when the power maintainer relay is energized (there is a short delay while the caps charge before the relay comes on). This relay is then pulsed using the parts and diagram described at the top of the page here
http://www.the12volt.com/relays/page5.asp - Constant to Momentary Output
Basically, this pulses when the inverter is turned on by the first relay.
Third- Computer off- This uses the shutdown controller software that allows the computer to shut down via pins 4 and 8 of the serial port being connected. I decided pulse would be unnecessary. This relay is energized when accessory is turned on. When it is turned off, the relay connects terminals 87a and 30, causing the shutdown signal.
I soldered all this to a project board that I had to grind to fit in the project box, both from radio shack. I have been testing it all day and it works great!
I imagine the only thing that may need to change is the pulse I use for wake-on-lan could be used on a power button. You would only have to make it disable the pulse while the computer is still on (or it will pulse the computer off if you come back before it shuts down).
I hope this helps someone, it was a lot of work and I know some people just want to see what a working mess looks like. You have seen the diagrams, and now the work—make one!
PS-everything but the caps were purchased at Radio Shack...sorry for the huge pics
Can you post a diagram of how you wired it? That's all I need... The pic of how it looks once it's done isnt so useful
This is the diagram I used, as I stated in the post. Connect the caps in parallel in place of the ones labled 4700uf and 1000uf.
Who are you quoting? I didnt see that written anywhere. Besides, that's not the same as what you have there.
Do you have a shot of the underneath of your board? The only reason I'm asking is that I tried building something like this, but I couldnt get it to work. Since yours works, you've obviously wired it differently to the way I've wired it.
I think he's refering to my first post in this thread: Ghetto Startup/Shutdown Control for Inverter
I'm kinda flattered, actually! Thank's for building on that design!
However, I must ask why you are using 10x10k caps! That many caps has got to cost a fortune and just adds to the potential failure points in the system. (not to mention instant death if you touch the wrong wire) (I'm assuming that you're using the caps to power the system...)
My circuit simply held the relay charged, which permitted the comp to run off of the main batt. By charging those caps, you're not really "conserving" any energy - simply storing it in another place.
Interesting idea, though.
CarPC Stolen. Starting over.
Ne1 recognize the avatar?
I am referring to your first post PatO, I am pleased to flatter. Basically, I built your design exactly for testing. I got the delay to work for 90 seconds as your diagram stated. I want the inverter to stay on longer then 90 seconds to maintain power to the computer while I get gas or run into a store for a few minutes.
I figured that if 4700uf is good, 10000ufX10 is better! It turned out to be the case. I purchased the caps off of eBay for $21. I choose 25v because there are smaller then comparable 35v caps and there were what I could find on eBay (I divided the 4700uf by the amount of time it maintained power, then just looked for enough ‘uf’ to give me ~7 min. Sloppy yes, but it worked, and this thread is called “ghetto”!)
On the contrary to it creating failure points, had I used only one cap, should that fail, the device is useless. Using many caps in parallel, if one fails, the delay is only shorter. Also, I am avoiding touching any of the wires, hence the box
So those caps do only power the relay, not the system. As I stated, it maintains the relay for over 7 minutes. The circuit is exactly the same, LEDs and all, except for the added caps for the longer time.
the realscott, sorry if my previous posts were confusing. I am new to the forum and am still not sure how the ‘quote’ system works so I just mentioned the diagram that I used. I thought if I used one more picture in my post I would be banned I would love to help, but I am positive that if you saw the bottom of the circuit board, you would only be more confused! It is a mess, and was a pain trying the get all the caps connected and run into the circuit (a hint is that I ran jumper wires on top of the board as well as made solder traces on the bottom to get it all connected) It does work, and I suggest starting over from scratch, I ran into the same problem and just started over when it did not work the first time with new parts. Be sure that the base, collector and emitter of the transistor are correctly connected and the diodes and LEDs are facing the right way. Stoopid I know but it happens. Let me know if I can help any more (or did I confuse you more?)
Now I will wait for someone to reply “TL DR”
No probs about the confusion. If you want to quote someone, by the way, just press the 'quote' button that's at the bottom of their message, rather than the reply button at the bottom of the page. You can delete any text you dont want from inbetween the quote marks... you'll see them if you use the quote button.
Anyhow, yeah, I dont know what's wrong with mine, I've been over it a few times, but I'm not that good with electronics. I might get my bro to take a looks, since it's what he does for a living lol!