Has anyone seen Lasersabers new motor runs on 1000uf cap

[Magluvin]

Hey Gyula

Yes I have 2 meters that measure freq. Will do when it gets here tomorrow. Will have it in the morning.

What I really want this lcr meter for is measuring windings on cores of unknown quality/value. I have some projects that have been set aside just for these reasons.
Been working a lot in the last year. Im tired at the end of the day.  Been having some breaks in work to get some of these things going again. I havnt put a vid up in a long time. Was doing some custom car audio on the side on top of my regular job. Killing myself slowly. But now I can spend a little on some equipment/tools Ive been meaning to get for some time now.

Mags

[Magluvin]

Ok, got the meter today. I first tested the coil you calculated the inductance on. It reads 82.6mh in the 200m scale and 83mh in the 2h scale. Not sure if that means much about the accuracy. But it is consistent.

I forgot to stop at my shop to get those known inductors. I moved some stuff there while the apt building was being tented a couple weeks ago. lol, I moved out a lot of stuff. For one, someone seeing my bench area, being the tent people must have the keys, yet are not responsible for anything, in the contract, someone might take seeing all that not just as pulse motors and such. If ya know what I mean. Also I have 2 pc's, 2 laptops, stereo, tv's, personal stuff. Ive seen news shots of people breaking into tented houses with gas masks. So, I played it safe.  And now for the lol. My nice kitchen broom was gone when I got back. So who knows if I left it all here.

The other functions work well, capacitance and resistance. Resistance down to .01ohm which is always nice. Great for locating the shorted component on the board without a lot of desoldering.  At times, it will only bring you close to the shorted part. My old Soundstream ref 705 had a short on the 15v rail for preamp and crossover circuitry. These lines go all across the board. But I found the shorted IC, 1 of 10 if I remember correctly, with my old Wavetek 2030. The IC was also looking a bit shinier than the others. I wasnt sure if it was the IC other than the shine, as it could have been a cap near by. But that was it once I desoldered it. It saves a lot of time in those cases. Also some bias resistors in amps are usually .15ohm, even .23 or .27ohm.  Now you can measure that accuracy confidently.


I checked the freq with a couple inductors that I have here. On the same scale, the freq changes with different inductors, also the same freq on most of the middle(4 of 6) ranges, but different freq in the 200uh and the 20h scales, all with the same 2 inductors just to see. So there is no one freq I can give you for the inductance. So maybe the meter puts a cap across the coil and sweeps for peaks.
The capacitance freq is 400hz for 200pf to 2uf.  80 hz for 20uf to 200uf and 10hz for 2000uf range

I checked the 200uh scale and it goes down to .01uh.

The meter is kinda cheap in comparison to what I have in dvms. The instructions are very basic. But it seems to work. Ill get those inductors tomorrow. They are car audio crossover parts.


Mags

[gyulasun]

Hi Mags,

Well, the measured value of 82.6 mH is rather far from my calculated value of 138.7 mH so something is wrong... 

Using another on-line multilayer coil calculator with the 82.6 mH and your bobbin sizes, the number of turns comes out as 3391 and DC resistance as 648.03 Ohm, the small problem is coil OD comes out as 22 mm (2*9.4+3.4=22.2). Here is the other calculator link:
http://coil32.narod.ru/calc/multi_layer-en.html  and it uses Maxwell equations and elliptic integrals, and considers both bare wire diameter and insulated wire diameter (I used 0.0682 mm bare and 0.085 mm for insulated wire sizes). Unfortunately, a micrometer is needed to check the actual wire diameter, caliper is not enough.
Here is a link to an LC meter which may use similar circuit whereby the oscillator frequency changes as per the unknown coil inductance dictates: http://my.integritynet.com.au/purdic/lc-meter-project.htm#circuit-osc 
I have seen LC meters with fixed frequencies where the frequency was derived from the clock of a microcontroller (or microprocessor) and it was a fix value within a measurement range. Higher end LC meters use a switchable low (100Hz-1000Hz) and a high frequency (10kHz-1MHz) value to cover very wide measurement ranges and also to have a better resolution.
I wonder what measuring frequencies you found with the L ranges approximately (it is okay it changes by the coils). Curious also about the type or make if you do not mind.

Gyula

[Magluvin]

Hi Mags,

Well, the measured value of 82.6 mH is rather far from my calculated value of 138.7 mH so something is wrong... 

Using another on-line multilayer coil calculator with the 82.6 mH and your bobbin sizes, the number of turns comes out as 3391 and DC resistance as 648.03 Ohm, the small problem is coil OD comes out as 22 mm (2*9.4+3.4=22.2). Here is the other calculator link:
http://coil32.narod.ru/calc/multi_layer-en.html  and it uses Maxwell equations and elliptic integrals, and considers both bare wire diameter and insulated wire diameter (I used 0.0682 mm bare and 0.085 mm for insulated wire sizes). Unfortunately, a micrometer is needed to check the actual wire diameter, caliper is not enough.
Here is a link to an LC meter which may use similar circuit whereby the oscillator frequency changes as per the unknown coil inductance dictates: http://my.integritynet.com.au/purdic/lc-meter-project.htm#circuit-osc 
I have seen LC meters with fixed frequencies where the frequency was derived from the clock of a microcontroller (or microprocessor) and it was a fix value within a measurement range. Higher end LC meters use a switchable low (100Hz-1000Hz) and a high frequency (10kHz-1MHz) value to cover very wide measurement ranges and also to have a better resolution.
I wonder what measuring frequencies you found with the L ranges approximately (it is okay it changes by the coils). Curious also about the type or make if you do not mind.

Gyula

Hey Gyula

DY-4070g   
http://www.dyinstrument.com/duoyi/?q=LCR_meter/DY4070G/DY6243G/DY6013G


It was $70.  There are some out there for $18.   After playing with it more Im growing to like it. And would recommend it so far. Much better can be had for twice as much or more. But this seems to do ok for our purposes.


Well your new calculation is just about there at 82.6mh.  The number of turns is 3300 and yours shows 3391  and the resistance is near spot on.    Thanks for looking into that. There may be differences in thickness of insulation to factor in. Also maybe subtract a fraction of a mm in outer dia due to the windings dont come out level with the bobbin diameter.  Anyways, very close.


I made this bifi coil with 26awg a couple weeks ago. Testing it I found very interesting results.

Measuring 1 of the 2 conductors measures 7mh. Same with the other. When I put them in parallel it measures 7mh. I wonder if one of those windings were say fishing line, non inductive, would the single winding still read 7mh? Like does the simple presence of the other non connected winding affect the result of measuring the other alone.

Then in series it measures 27mh.  Its bifi, so may not be correct.


Tested it multiple times to be sure.

Ok I think I get what your saying on the freq of the meter.  I measured the freq without an inductor connected. 

200uh scale     786hz
2m   20m   200m  2h    217hz
20h  for some reason reads 222hz

Mags

[Magluvin]

Here is a pic of the test leads shorted in uh scale.  I made a mistake in my last post. .1uh not .01uh

Mags