help with IR2110 chips

[Maglatron]

50mH as I recall. Even that will drop a considerable voltage.

recall from a fact in the past or something from this thread?

 

[Maglatron]

so first of all, I have to stick the rest of the magnets and mount the new wheel and mount the other coil that I have and run some experiments. I don't want to get too far ahead of myself! thanks

 

[Maglatron]

more glue just come so I'll see if I can get the rest of the magnets on and take some snaps! anout mount the other 7ohm coil

 

[Alec_t]

I think there are 28 layers = (20mm / 0.7mm)

Looks right. I was thinking 14 per cm but omitted the 2cm. My bad. Guestimate re-called from this thread.
With 2800 neat turns, average diam 3cm, turn circumf = pi*3 cm, wire length = pi*3*2800 = 264 metres. Doesn't sound right.
If 264 metres, with copper density 8.94g/cc, that would weigh 909gm. So we're out by a factor of nearly 2.

drop??

Yes. Impedance of an inductance impedes current flow so results in a voltage drop.

 

[Maglatron]

ok now I have the magnets stuck and will upload picutes after 6, its dinner in 15mins and I actually do have that information didn't think to check

 

[Maglatron]

and before you say by more of those, they're out of stock!

 

[Alec_t]

and before you say buy more of those, they're out of stock!

I've already said I wouldn't buy anything more yet

 

[Maglatron]

so I might add that they are not the neatest wound coils in the world but I think they shall suffice to be fair!

Looks right. I was thinking 14 per cm but omitted the 2cm. My bad. Guestimate re-called from this thread.
With 2800 neat turns, average diam 3cm, turn circumf = pi*3 cm, wire length = pi*3*2800 = 264 metres. Doesn't sound right.
If 264 metres, with copper density 8.94g/cc, that would weigh 909gm. So we're out by a factor of nearly 2.

I've already said I wouldn't buy anything more yet

ok I will take it on board, no more buying as of the moment!

 

[Alec_t]

This calculator might be a better bet, except that it seems to be for air-cored coils only.

 

[Maglatron]

does look rather good perhaps combining the information that it does give with core dimensions for instance we can find a better number more realistic to that of real life, thanks

 

[Maglatron]

heres some photos of the very naked machine along with both sides of the new wheel, (still needs mounting, two man job!) it might not look much but I didn't know what to snap when I had the camera! there are pictures of the hall effect sensor on one of them and the arduino that runs the screen for the RPM monitor you can see a bearing you can see quite a few trolley wheels and the coil that is mounted the next coil will go directly opposite and across from the first, any questions, feel free to ask!, thanks on pic 227 is the bearing bearly in view in a custom block thats made of metal

 

[Maglatron]

so last night when mounting the new wheel I had a disaster the thing broken some of the plastic so spent 45 mins this morning fixing and making more sturdy have to fit the coils and the run it up the balancing seems better with this new wheel thoughand so now it should be better than before

 

[Maglatron]

so the wheel is mounted and I mounted two coils they'er identical, however one makes 11volts AC and the othe makes near to 9volts AC going to try and reduce the gap between the coils and the magnets next but as of yet the initial reading doesn't differ that much from the 8 magnet-a-side wheel at similar speed 550rpm

 

[Alec_t]

two coils they'er identical, however one makes 11volts AC and the othe makes near to 9volts AC

If that's the open-circuit voltage, what do you get with, say, a 100 Ohm load resistor connected across the coil?

 

[Maglatron]

I will check that out, what should it be vaguely? thanks

 

[Maglatron]

sorry for the crude drawing do I measure over the coil or with the resistor in series with the meter the grey is the resistor and the brown box represents the meter

 

[bertus]

hello,

the resistor should be connected as the top drawing.
the voltage measured then will say something about the loss in the coil resistance

bertus

 

[Maglatron]

ok cool I'll give it a bash! thanks

 

[Martaine2005]

ok cool I'll give it a bash! thanks

Remember, a load is across the output (parallel). Not series like your bottom drawing.

 

[Maglatron]

so at 600rpm it reads 11volts AC without resistor with resistor it reads 6.8volts AC working on the machine right now took the reading of the coil that put out most gut feeling tells me this is not too bad!! 100ohm resistor!