A coil gun missing part problem

[Terminator Electricity]

toy car coil mechanism

Hi

**broken link removed**

this is a circuit 4 a coil gun

but there is a part that i couldnt find it anywhere

it is : SCR S6025L


Any way


I am plannig 4 my project to be an ejection seat

could a lower cost simpler coil gun do the trick ?

(using ofcourse a toy car and a toy seat)

and if it does , can anybody help me with a comlete design or help me make my

own design ?

10x ,
[/img]

 

[IanP]

lorentz coilgun

The S6026L thyristor is a general purpose 600V SCR (with isolated tab) rated for 25A, see table below .. https://www.darisus.de/Elektonikshop/Datenblaetter/TECCOR/S2006D.pdf ..
It can be replaced by any other SCR rated for similar voltage and current, for example, BT152-600, 25TTS08, and so on ..

I don't think there is anything wrong with this design .. go for it ..

Regards,
IanP

 

[Terminator Electricity]

would BT151 work as well?

 

[IanP]

The BT151-XXX are rated for 12A, but in this application I can't see any reason why not ..

Regards,
IanP

 

[Terminator Electricity]

ur help is very much appriciated , 10x

one more question plz

wat type of coil i should use : length , diameter, number of turns ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

for the transistors used in this circuit, can i used any transistors ?

 

[IanP]

Try to construct a coil as per attached picture ..
More details you can find at: **broken link removed**

Regards,
IanP

 

[Terminator Electricity]

wat is meant by washers ?

 

[IanP]

As far as the NPN transistors are concerned, any general purpose NPN will be OK ..
P2222, 2N2222, BC107, BC .. , ZTX .. and so on ..

Regards,
IanP

 

[Terminator Electricity]

ok , 10x , but should i separate the 3 coils by distance or 2 be continues?

 

[IanP]

The iron washers will just increase the magnetic field strength of the coil ..
If you don't want to, you may not use them, but they can help ..

Regards,
IanP

 

[Terminator Electricity]

does the diameter of the coil have to be at certain

ammount or any diameter would do the trick ?

would it melt if it was too thin ?

 

[Buriedcode]

hi

would it melt if it was too thin ?

I doubt it. What the circuit does it charge a capacitor (5000uF) and then this is shorted through the coil via the SCR. The discharge will be very quick, and some of the diodes will prevent oscillation (also known as 'ringing') where the energry is dumped into the coil, from the cap, and then the coil dumps some energy back into the cap...just like an LC circuit.

The discharge will be very quick, under a ms. But....if you were to use a massive capactior and some very thin wire, there is a small chance the wire in the coil could explode. You're ok with a 5000uF cap.

does the diameter of the coil have to be at certain
ammount or any diameter would do the trick ?

I don't think there are any 'rules', you're just creating a massive magnetic field for a very short period. I'm unsure of how you are going to 'eject' your seat? Most coil guns, have a projectile placed just outside the coil, when the coil is enegised, the projectile it strongly attracted to the centre of the coil, but the pulse has stopped by the time it gets there, so it just goes through the coil, and out the other end.

Some designs, that can be more efficient, use the Lorentz force. Put simply, any coil nearby your coil, will have a current induced in it, of opposite polarity. If this secondary coil is closed (like a ring of aluminium) then current will flow in it, producing its own magnetic field.....which again, is opposite to the first coils polarity....the effect? They repel like theres no tomorrow Also, because the secondary coil is simply a 'ring' (a single turn on a transformer) the voltage from the first coil is stepped down....by *1st coil turns : 1* And the current is stepped up. Because magnetic field strength is determined by current flow, this makes the effect quite impressive.

Anyway, I'm just ranting now....sorry, back to your problem.
The coil would simply require experimentation. From school, the properties of a coil that determine field strength are:
-Diameter of wire (you want it fairly thick)
-Some sort of 'core' (iron probably, or some sort of ferrite material)
-Number of turns in the coil

And obviously current. You might not want to have too many windings....more windings = higher resistance = less current flow. But anything under 500 turns should be OK.

Hope this helps, at least in some way :/

Finally, your SCR. I'm sure it will be fine, but I built a 'pulser' a while back, very similar design to yours...used for Xenon Tubes, Coil guns, rail guns etc.. And the SCR nearly always 'latched'. That is, once fired, the SCR remained 'on' and could not be turned off. It was rated at 800v and peak of 120A. Think I blew it.
If you want a substitute SCR....check the max Voltage, and peak current. It won't be conducting all the time, so av. current is meaningless.

Regards,

BuriedCode.

 

[IanP]

I am not sure if Buriedcode used protective diodes (see picture below) around the coil when blew his SCR, but in your case all three diodes make sure that you are protected against positive (D5 -->C3 path) and negative (D3 and D6) spikes at both sides of the coil ..

Regards,
IanP

 

[Terminator Electricity]

10x ,

could I ask one more question ?

wat could be the transformer current ?

another thing , I couldnt find the 24 CT

how can i use two transformers instead ?

10x again

 

[IanP]

The transformer's current won't be high .. After all the 5000µF caps are charged through 1kΩ resistors .. I would say, if a transformer is rated for more than 100mA it will work ..

I don't think you need two transformers .. Try to use one 24V transformer .. The 7805 regulator can handle voltages up to 35V so all what you may need is a small heatsink for the 7805 ..

Regards,
IanP

 

[Terminator Electricity]

heatsink ?????????????????????

wat do u mean by that ?

For the transformer , i couldnt find any 24 v CT

so i was advised to use two transformers(12v) instead , but i dont know how 2 connect them together

Added after 1 minutes:

and yeah,, aslo wat fuse current i should use ?

10x ,

 

[IanP]

I suggested heatsink for the voltage regulator if you ran it of full 24Vac ..
If you have two 12V transformers you will not need it ..

As far as the transformers are concerned, connect their primary windings in parallel, so both primary winding will be fed of the mains, and connect the secondary windings in series, so where they are connected together is the CT point ..

Depending on the power rating of your transformers, the primary fuse may be sized at 250% of transformer primary current, for example, 10VA transformer running at 120Vac and full rating load will draw ≈85mA .. use 250mA slow-blow fuze ..

Regards,
IanP

 

[Terminator Electricity]

Another question plz , i have finished connecting the circuit

how much distance is barable between the emmiter and the reciever in order to still have a signal ?

 

[IanP]

The best thing to do is to build a simple test circuit ( see picture below ) and test them ..
I don't think you can estimate that distance just by reading data shits ..

Regards,
IanP

 

[Terminator Electricity]

hey, i have tried the coil gun

how much does it take 4 the capacitors to fully charge ?

if it took 4ever 2 charge , what could be the problem ?

Added after 2 hours 27 minutes:

Another thing , the capacitors r not charged !!!!!

the voltage accross the first one is 21.7 v

the others each has a voltage of 0.7 v

plz answer fast

cuz i am trying the circuit right now

10x,