MW Immortalking
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@Thatdecade, They seem lighter than a netbook
"Help!" for: Electronics
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Glad I could help Sol
thatdecade
Well-Known Member
Happy to help
I have a quick question regarding my recoil simulation... to get a short burst of energy into the solenoid (*1), I want to use a capacitor hooked up parallel to the battery (*2). But what characteristics are important and how do I calculate the neccessary capacity to make sure this works in full auto mode? That means one shot every 111 ms (=9Hz), and maybe some more electromagnet-action in between as well (*3).
Some more explanation that I pulled down here to keep the question short:
*1: In my case probably two electromagnets, shouldn't make much of a difference though. 12V (24V also available, but 12V seems better), 3.8 to 6W and either 60, 100 or 200N, depending on what fits in the prop
*2: Most likely a high-powered rechargeable NiMH battery for models
*3: I want to use the burst I mentioned to generate the recoil-effect, but I want the option to use PWM to slightly slow the weight down on its way back to the starting position. That way, I hope to make this second acceleration in the opposite direction "feel" softer and make the actual recoil stand out more. Without dampening the return movement, the result would probably just some kind of linear vibration instead of halfway realistic recoil.
Some more explanation that I pulled down here to keep the question short:
*1: In my case probably two electromagnets, shouldn't make much of a difference though. 12V (24V also available, but 12V seems better), 3.8 to 6W and either 60, 100 or 200N, depending on what fits in the prop
*2: Most likely a high-powered rechargeable NiMH battery for models
*3: I want to use the burst I mentioned to generate the recoil-effect, but I want the option to use PWM to slightly slow the weight down on its way back to the starting position. That way, I hope to make this second acceleration in the opposite direction "feel" softer and make the actual recoil stand out more. Without dampening the return movement, the result would probably just some kind of linear vibration instead of halfway realistic recoil.
thatdecade
Well-Known Member
There are some good java calculators you can find online to calculate the charge and discharge time of your capacitor. Add these times together. Since you want 111ms your cap has to charge at least twice as fast, 0.055 s.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c2
Edit: I posted my solenoid circuit a few pages back. Let me know if you can't find it.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c2
Edit: I posted my solenoid circuit a few pages back. Let me know if you can't find it.
I've bookmarked the whole thread with your two circuits in it for future reference ;-)
I also thought about just copying the capacity you used, but I would rather like to know what I'm doing.
What exactly would I enter on that page you linked? The resistance while loading is zero, so do I use the magnet's resistance, enter the voltage I want to use and then just increase the capacity until I get a charge of 1 Q_max after t=0.05 s?
(I'm feeling a little stupid right now...
)
thatdecade
Well-Known Member
Resistance is never zero, entering zero breaks the equation. If you scroll up on that page you can see how the equation works. You can make an assumption and use the wire resistance of 0.1 ohms.
The page will calculate the the RC time constant for you. If you enter a time reference, "At time t", it will tell you the % charge on the capacitor, "and the charge on the capacitor is".
I put some examples below.
If you go to the capacitor discharge calculator page, you can figure out how much amperage a capacitor will provide. Plugin the same info (use your electromagnet coil resistance for R) and look at this section "the current is = Imax = A,".
If I set "At time t =" 0.1s, I would find what current the capacitor can currently output "current is =" and what the max current was when the capacitor was full "Imax =".
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html#c2
Some examples using the capacitor charging calculator.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c2
In the first example you can see that the capacitor has a 100% charge after 0.1 seconds of charging.
capc3 by thatdecade, on Flickr
In the second example you can see that the capacitor only has a 56.5% charge after 0.001 seconds of charging.
capc2 by thatdecade, on Flickr
The page will calculate the the RC time constant for you. If you enter a time reference, "At time t", it will tell you the % charge on the capacitor, "and the charge on the capacitor is".
I put some examples below.
If you go to the capacitor discharge calculator page, you can figure out how much amperage a capacitor will provide. Plugin the same info (use your electromagnet coil resistance for R) and look at this section "the current is = Imax = A,".
If I set "At time t =" 0.1s, I would find what current the capacitor can currently output "current is =" and what the max current was when the capacitor was full "Imax =".
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html#c2
Some examples using the capacitor charging calculator.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c2
In the first example you can see that the capacitor has a 100% charge after 0.1 seconds of charging.
capc3 by thatdecade, on Flickr
In the second example you can see that the capacitor only has a 56.5% charge after 0.001 seconds of charging.
capc2 by thatdecade, on Flickr
thatdecade
Well-Known Member
Glad to hear it, good luck~!
spartan227
New Member
hey thanks for the help!!
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Late to the meeting
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ok back story time im biulding a spartan laser I need it to light up at one end but as you guys know the laser has to charge to fire. so the brightness at the end of the barrel 1 needs to slowly increase and it also needs to be really bright LEDs are neccisary. (obviously) but i'm thinking three diffrent rings of LEDs that power up at diffrent times theres a delay between them, in other words. other materials besides the basic wires, LEDs, switches, batteries I have those other matierials needed it would be nice if you could post those along with your idea. so boys and girls if you would please...... HELP ME FIRE MY LAZER BBBAAAAHHHHHHHHHHHHHHHHHH.
thatdecade
Well-Known Member
So two rings of LEDs and a flash bulb in the center? Can do that without any fancy circuit. Remember the old electric toy car racing tracks? The remote control is wired to the track and is nothing more then a potentiometer connected to a trigger. Further down you press the trigger, the more voltage is sent to the cars.
So do something like that. First ring is connected directly to the trigger pot and will start glowing immediately when the trigger is pressed slightly. The second ring is connected through a small power resister to the trigger pot. Pushing the trigger down half way will increase the voltage enough that the second ring start to glow.
The center bulb can either be a separate switch or a microswitch underneath the trigger pot. Pressing the trigger down all the way will light the center bulb behind a red filter.
---------------
The other way I have suggested doing a spartan laser in the past is to use the circuit from a disposable camera. They have two buttons, charge flash, and take picture. Press the first button and watch a small LED slowly get brighter and brighter, when it's at it's max brightness press the second button, take picture, to activate the flash.
Modifying this to a spartan laser is pretty simple actually. Strip down the casing. Remove the charge indicator LED and replace with a transistor. The transistor will power the LED array in your outer ring. You can probably guess the rest.
So do something like that. First ring is connected directly to the trigger pot and will start glowing immediately when the trigger is pressed slightly. The second ring is connected through a small power resister to the trigger pot. Pushing the trigger down half way will increase the voltage enough that the second ring start to glow.
The center bulb can either be a separate switch or a microswitch underneath the trigger pot. Pressing the trigger down all the way will light the center bulb behind a red filter.
---------------
The other way I have suggested doing a spartan laser in the past is to use the circuit from a disposable camera. They have two buttons, charge flash, and take picture. Press the first button and watch a small LED slowly get brighter and brighter, when it's at it's max brightness press the second button, take picture, to activate the flash.
Modifying this to a spartan laser is pretty simple actually. Strip down the casing. Remove the charge indicator LED and replace with a transistor. The transistor will power the LED array in your outer ring. You can probably guess the rest.
spartanb312
Member
i may use this information
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Late to the meeting
Guest
thanks decade your a good man I will see how this all works out the camera Idea is good but that LED ring is still the overall best I even have a heavy duty flash nlight that is busted that i can use
L
Late to the meeting
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Hey decade can you help this guy with his head set is a simple LED fix (Fallout New Vegas, NCR Veteran Ranger Armor)
Other question i m kinda of stuck at this fan thing I wonder can I buy this http://www.radioshack.com/product/index.jsp?productId=2261643 and cut the end wire and put 9volt on it and an switch? or is there better one premade or something like that out there?
thatdecade
Well-Known Member
Yes, you can run a 12V fan meant for a pc with a 9V battery.
Here is a link to the fan I get from digikey to sell in my store. It is similar priced To your radioshack one and the batteries will last longer because it can run on 3AAA.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=259-1345-ND
Here is a link to the fan I get from digikey to sell in my store. It is similar priced To your radioshack one and the batteries will last longer because it can run on 3AAA.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=259-1345-ND
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