Why does a copper coil stop circuit from working?
- Thread starter Tony357
- Start date
no i dont have a data sheet sorry as i dont really understand what is written on it mostly
What length, of what gauge wire, did you use for each coil? This information will allow an estimation of the coil properties.
The unit of inductance is the henry. It is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England. Thus a millihenry is one one-thousandth of a henry.
The drawing shows a transistor, used as a switch, to allow current to flow in the coil.
Wouldn't the intervals need to shorten as the projectile accelerates? I wouldn't think a uniform clock would work very well. In other words, I don't think the TS is making a rail gun. At least not a very good one.
DickCappels
- Joined Aug 21, 2008
- 10,187
Please, don't start a rail gun discussion.
I recall one in a magazine years ago that worked like this, but don't know if it actually worked.
Thank you , This is not for a rail gun or any weapon. more like for decoration
I used copper from an old TV to make the coils as it was thinner than the one i had bought.
it should kind of look like a fan motor to a pc but bigger I think?
Thanks for clarifying, Tony.
The mA output capability of the 4017 is barely enough to light an LED and is not enough to make much of a magnetic field. You will almost certainly need the current boost transistor and sketched by #12 in post #16.
It can be challenging to power a coil. Too little wire length and the DC resistance is too low, causing an excessive current draw on your power supply. This will cause the weakest link to burn up, whether it's a fuse, the coil itself, the power supply, whatever. The power supply might simply sag in voltage without burning anything up, but it's not good to rely on that.
Too much wire length gives too much DC resistance and you don't get the current you need to make a field.
Ah, TV coil wire. I believe the one I used was 28 gauge. Unless you have a lot of loops and used a lot of length, the resistance will be quite low, less than 10Ω I would guess. Easy enough to measure if you have a multimeter.
The mA output capability of the 4017 is barely enough to light an LED and is not enough to make much of a magnetic field. You will almost certainly need the current boost transistor and sketched by #12 in post #16.
It can be challenging to power a coil. Too little wire length and the DC resistance is too low, causing an excessive current draw on your power supply. This will cause the weakest link to burn up, whether it's a fuse, the coil itself, the power supply, whatever. The power supply might simply sag in voltage without burning anything up, but it's not good to rely on that.
Too much wire length gives too much DC resistance and you don't get the current you need to make a field.
Ah, TV coil wire. I believe the one I used was 28 gauge. Unless you have a lot of loops and used a lot of length, the resistance will be quite low, less than 10Ω I would guess. Easy enough to measure if you have a multimeter.
Thanks for your reply Wayneh.
The coils i have made produce the right field, is there a circuit that can fire 7 coils one after another? As i would really like to complete this part of the project.
sorry what is an RLC meter or L meter?
RLC - a multimeter at least have three measure functions as R - resistor, C - capacitor, L - coil, L meter is special meter only can measure coil and the unit as uH, mH, H.
It also have some others as LC meter and you can DIY or to buy one.
You can DIY as below.
Simple DIY inductance meter (L-meter).
Can you describe how you tested your coils? Was it perhaps by direct connection to a power supply?
Your circuit is the right idea and is exactly how I would do it, but the 4017 outputs need to be amplified with external transistors. A transistor array which contains multiple transistors in one package might be a handy option. See ULN2803 or ULN2003.
