How can I build a stronger coil

[jan-willem]

I do build homemade electric parts, timers etc. from wood. What is the best way to build a strong electric coil. My coil looks not so stong. Do I have to make the coil longer or wider? I just did started doing this and do not know how to build a strong one.
This is the video I did make from my second machine. A electric timer relay from wood, iron, copperwire and 2 magnets.

 

[pc1966]

The magnetic field depends on the "ampere turns" (i.e. current in coil times number of turns) as well as the magnetic reluctance of the circuit (so combination of the magnetic core which looks to be steel, and the air path).

Reducing the reluctance which is probably dominated by air-path is probably simplest (smaller gap, or magnetic core wrapped round), but failing that having more current per turn (so generally more copper so higher current and/or more turns for same current).

 

[jan-willem]

I do build homemade electric parts, timers etc. from wood. What is the best way to build a strong electric coil. My coil looks not so stong. Do I have to make the coil longer or wider? I just did started doing this and do not know how to build a strong one.
This is the video I did make from my second machine. A electric timer relay from wood, iron, copperwire and 2 magnets.

I do build homemade electric parts, timers etc. from wood. What is the best way to build a strong electric coil. My coil looks not so stong. Do I have to make the coil longer or wider? I just did started doing this and do not know how to build a strong one.
This is the video I did make from my second machine. A electric timer relay from wood, iron, copperwire and 2 magnets.

 

[jan-willem]

The magnetic field depends on the "ampere turns" (i.e. current in coil times number of turns) as well as the magnetic reluctance of the circuit (so combination of the magnetic core which looks to be steel, and the air path).

Reducing the reluctance which is probably dominated by air-path is probably simplest (smaller gap, or magnetic core wrapped round), but failing that having more current per turn (so generally more copper so higher current and/or more turns for same current).

Thanks PC1966, I do not know to much from electrics so for me it is a great help.

 

[Lucien Nunes]

Agree, you will benefit most from a closed magnetic circuit. The magnetism is strongest when there is a complete iron / steel path in a loop from one end of the solenoid to the other. Just as the copper in an electrical circuit offers a low resistance to carry and direct the current, the iron path offers a low reluctance to carry and direct the magnetic flux. With a reluctacnce actuator like your tilting timer mechanism, or a relay, obviously there needs to be some gap in the iron circuit so that the armature can move into it. But it should be no bigger than needed for that movement, and the remainder of the path is entirely iron / steel.

Look at the magnetic circuits (iron components) of commercial relays, contactors, solenoids, motors and you will always find the iron path made as short and thick as possible, for maximum efficiency. For example, this solenoid (which has a laminated steel core for AC operation) has a magnetic circuit that is completely closed when the travel is complete: the flux comes out of the coil, up the armature and out of its 'wings', then back to the far end of the coil down the side limbs.

Pull Action AC Laminated Solenoid, 9VA, 24 V ac | STL1 | ET16838296 | Enrgtech LTD

Buy the Pull Action AC Laminated Solenoid, 9VA, 24 V ac. STL1 Solentec Limited Linear Solenoids. FREE shipping for UK customers on ET16838296 product.

www.enrgtech.co.uk

BTW, fun gadget!