HOW TO: Make a capacitor bank useful for many applications, ie a railgun, coilgun, RFID zapper, for $0~50 depeneding on what tools you have and how fancy you want the final product.
**Now with solid state trigger**
**Now with solid state trigger**
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Signing UpStep 1: Gather Materials
I have modified the circuit to use a solid state trigger, an SCR. I used this one, number from digikey: S4020L-ND
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=S4020L-ND
400v, 20A so ~200A surge, less than $2
The pins are, from left to right: Anode; Cathode; Gate
The SCR is essentially a diode, so be sure to hook the negative of the caps to the cathode and the anode to one of the binding posts. The positive of the caps also goes to a binding post. When you put enough current (check the chip spec, only a few volts and ma IIRC) through the gate it is "closed", allowing current to flow through it in the right direction. It will stay "closed" until the current flow stops, IE the caps are completely drained. Then you can just solder up a switch to the positive lead from the battery holder to the gate, this way you will be able to discharge even when the switch is off. I will put a new schematic up soon.
I applied all this to a coil gun and will write it up soon. This is just and update for those who request a solid state switch.
*****************************************************************************************************
Keep in mind that this is my first instructable, hell it's my first time wielding a soldering iron. Comments appreciated :D
The cheap way: (note that if you choose to go this way you should skip to step 4)
$0.00 (4) Disposable cameras You can get these for free used
$0.00 (X) Scraps of wire I used the wires from an old stereo system
$7.99 (1) Spool of solder (with soldering iron!)
$4.99* (1) Spool of 12 AWG wire.
$3.68* (1) Electrical tape
~$12
Assuming you already have everything but the 12AWG stuff, which you probably do, that's only $5. Hell, you could probably get away with paperclips if you were really trying to get it done cheap.
Required materials:
$0.00 (4) Disposable cameras You can get these for free used
$0.00 (X) Scraps of wire I used the wires from an old stereo system
$1.39 (1) LED holders (package of 2)
$1.49 (1) Green LED (package of 2)
$1.49 (1) Red LED (package of 2)
$3.00* (1) Toggle Switch
$1.49 (1) 2AA Battery Holder
$3.69 (1) Project Box
$4.99 (1) Binding Posts
~$17
Things you probably have but might not:
$7.99 (1) Spool of solder (with soldering iron!)
$4.99* (1) Spool of 12 AWG wire.
$3.68* (1) Electrical tape
~$38.20
*I just guessed the prices of *'ed items
I got all those parts at radio shack, expensive but that's what I pay for convienence.
Tools:
Soldering Iron
Multimeter
Drill
Assorted drill bits
Scissors
Note that I took the picture after I finished the project...
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=S4020L-ND
400v, 20A so ~200A surge, less than $2
The pins are, from left to right: Anode; Cathode; Gate
The SCR is essentially a diode, so be sure to hook the negative of the caps to the cathode and the anode to one of the binding posts. The positive of the caps also goes to a binding post. When you put enough current (check the chip spec, only a few volts and ma IIRC) through the gate it is "closed", allowing current to flow through it in the right direction. It will stay "closed" until the current flow stops, IE the caps are completely drained. Then you can just solder up a switch to the positive lead from the battery holder to the gate, this way you will be able to discharge even when the switch is off. I will put a new schematic up soon.
I applied all this to a coil gun and will write it up soon. This is just and update for those who request a solid state switch.
*****************************************************************************************************
Keep in mind that this is my first instructable, hell it's my first time wielding a soldering iron. Comments appreciated :D
The cheap way: (note that if you choose to go this way you should skip to step 4)
$0.00 (4) Disposable cameras You can get these for free used
$0.00 (X) Scraps of wire I used the wires from an old stereo system
$7.99 (1) Spool of solder (with soldering iron!)
$4.99* (1) Spool of 12 AWG wire.
$3.68* (1) Electrical tape
~$12
Assuming you already have everything but the 12AWG stuff, which you probably do, that's only $5. Hell, you could probably get away with paperclips if you were really trying to get it done cheap.
Required materials:
$0.00 (4) Disposable cameras You can get these for free used
$0.00 (X) Scraps of wire I used the wires from an old stereo system
$1.39 (1) LED holders (package of 2)
$1.49 (1) Green LED (package of 2)
$1.49 (1) Red LED (package of 2)
$3.00* (1) Toggle Switch
$1.49 (1) 2AA Battery Holder
$3.69 (1) Project Box
$4.99 (1) Binding Posts
~$17
Things you probably have but might not:
$7.99 (1) Spool of solder (with soldering iron!)
$4.99* (1) Spool of 12 AWG wire.
$3.68* (1) Electrical tape
~$38.20
*I just guessed the prices of *'ed items
I got all those parts at radio shack, expensive but that's what I pay for convienence.
Tools:
Soldering Iron
Multimeter
Drill
Assorted drill bits
Scissors
Note that I took the picture after I finished the project...
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And @TheDeviant13: What do you mean "will make CRT TVs"? It will screw up the picture pretty bad, but that goes for all magnetic fields.
What do you mean by attach the anode to the scr? do we attach the thing to itself?!
I am making a charging circuit for a coilgun, but i accidentally bought non polar caps. I was wondering if i could still use these with some sort of circuit adjustment, or if i need to purchase all new polarized caps? Can you help?