How to make a simple delay circut.

[BadNewsBears]

Electricit goes in. (9v ish) And then in about 45 seconds the juice comes out the otha end. How do i do it?

 

[diskop]

Put some capacitors in the middle I think.

 

[BadNewsBears]

Lol ok what size how many how much time will it giv me?

 

[Killbat]

Yes, a cap in series should do it, but you have to realize that A) you're going to need a good-sized cap for 45 seconds and B) if there's much load on this you're going to need a resistor in there to keep that cap from sucking in all the electricity within 7 parsecs.


I had this capacitor array to power my gauss gun (don't ask), and I used a couple diodes as a voltage doubler to charge the array directly from line AC. I had to add some huge resistors to it because every time I charged the thing, every light in the house would blink.

 

[ATLien247]

Originally posted by: Killbat

I had this capacitor array to power my gauss gun (don't ask), and I used a couple diodes as a voltage doubler to charge the array directly from line AC. I had to add some huge resistors to it because every time I charged the thing, every light in the house would blink.

You said not to ask... but I'm going to anyways. Gauss gun?

 

[Killbat]

I don't have any digital information on my gun.
oooh, picture

Search Google for coil gun or gauss gun.

 

[skyking]

Ic chip kit from radio shack might do it for ya too. They have always had programmable delay circuits and stuff in the catalog.

 

[Anubis]

Originally posted by: Killbat
Yes, a cap in series should do it, but you have to realize that A) you're going to need a good-sized cap for 45 seconds and B) if there's much load on this you're going to need a resistor in there to keep that cap from sucking in all the electricity within 7 parsecs.


I had this capacitor array to power my gauss gun (don't ask), and I used a couple diodes as a voltage doubler to charge the array directly from line AC. I had to add some huge resistors to it because every time I charged the thing, every light in the house would blink.

sweet gauss gunes are cool we had one but we melted it when we hooked it to the BFC (big Freekin Capacitor. something more then a cople farrads i think) in our plasma lab. how far/fast youget your to shoot and what size object you launce with the thing

 

[Killbat]

Originally posted by: TheEvil1

Originally posted by: Killbat
Yes, a cap in series should do it, but you have to realize that A) you're going to need a good-sized cap for 45 seconds and B) if there's much load on this you're going to need a resistor in there to keep that cap from sucking in all the electricity within 7 parsecs.


I had this capacitor array to power my gauss gun (don't ask), and I used a couple diodes as a voltage doubler to charge the array directly from line AC. I had to add some huge resistors to it because every time I charged the thing, every light in the house would blink.

sweet gauss gunes are cool we had one but we melted it when we hooked it to the BFC (big Freekin Capacitor. something more then a cople farrads i think) in our plasma lab. how far/fast youget your to shoot and what size object you launce with the thing

Could lob some 3" nails about 60' or penetrate soda cans at close range. It was really crude, single stage coil was too wide for the projectile, plus my cap array was only a few hundred joules. Still, yea, she warmed up. My coils went from freezing to too-hot-to-touch with only one shot. I wanted to fine-tune the coil size and make two or three stages, but I didn't have the cash monies$s$.

 

[Harvey]

Use an R-C network to control a comparator that drives a relay driver or FET switch. You can use an actual comparator or a rail-to-rail op-amp.

No graphics in these, so I can't post a pic. PM me if you need me to e-mail you a schematic.

 

[Calundronius]

I'm not 100% sure, I haven't done charge-time stuff with capacitors in a long time, but I don't think a simple capacitor by itself would work...for a delay of 45 seconds you'd need a really huge capacitor, or such little current as to make the circuit useless.
I messed around with google and found something I actually understood that also did what you wanted. It's a very specific design for some toriod thing, but it does show the basic setup.
A delay circuit (and other stuff)
(Note: I'm not sure how much you know about circuits so I'm sorry if I over explain stuff.)
I don't know if you're working with AC or DC. If you're using DC, then some of this is extra. You wouldn't need the rectifier, that's the 4 diodes, and then R1, R2, and R3.

Basically, the way it works revolves around the relay (Re1 on the diagram)...basically, when the voltage across the capacitors reaches a certain amount, the relay closes the switch, letting current flow. The time it takes depends on how big the capacitors are...you can search google for capacitor equations and find one that involves how long it takes something to charge if you know the current, etc.
I'm not 100% sure, but I don't think you need the series of resistors R4 to R7, which keeps the current very low until the relay closes. Since you don't want any current right away, you don't need that part.

If you are using ac current, then you will need pretty much everything on the diagram, except for K2, which dosen't do anything as far as I can tell. You can't just use AC current on the capacitor and relay setup because the capacitors wouldn't charge properly.

You could also replace the rectifier and R1, R2, and R3 with any old DC converter you may have lying around, but make sure you know how much voltage and current it gives out, so you know what kind of capacitors and relay to get.

Don't necissarily use the values the diagram uses, since the delay circuit there is set up for very specific results.
I'd start by finding a relay....probably radioshack or somewhere online. After you know what voltage it takes to close the switch, you can figure out what kind of capacitor you need by finding that charging equation, and then plugging in your time, and the voltage.

Whew.

I can't guarantee any of this is completely accurate (haven't earned that degree yet), but this should get you started, hopefully.

 

[NuclearFusi0n]

find a clock that has a rotating arm. set it up so it rotates and meets a point in 45 seconds, stick a needle at that point. when the hand reaches the needle, the circuit closes.

 

[J0hnny]

Originally posted by: NuclearFusi0n1
find a clock that has a rotating arm. set it up so it rotates and meets a point in 45 seconds, stick a needle at that point. when the hand reaches the needle, the circuit closes.

The best and only way!