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Magnetic Current Sensor — Parallax Forums

Magnetic Current Sensor

ProgressProgress Posts: 11
edited 2011-11-03 19:10 in Accessories
Hi guys,

I am looking for a cheap, light (very important), magnetic current sensor like this one:

http://www.rcplanet.com/Hitec_HTSC50_50_Amp_Current_Sensor_p/hrc55850.htm

It should be rated for 30~50 Amps. This is the only one I have found so far, but I'm sure there are more out there. All I have been coming across are giant current sensors. The sensor should also be non contact so it must be a magnetic one like this.

I was wondering do you guys know sites /stores where I might find more of these (perhaps lower current ---> lower cost)?

Thanks

Comments

  • SeekerSeeker Posts: 58
    edited 2011-11-03 16:19
    I think a lot of this comes down to what you are trying to measure. AC/DC, frequency of signal, min current vs max current. This could be an easy DIY sensor depending on what you are trying to measure.

    If you provide more details, maybe we could come up with a few ideas.
  • ProgressProgress Posts: 11
    edited 2011-11-03 16:34
    Oh sorry I forgot to mention the most important thing heh, I'm trying to measure the instantaneous current. The idea is to have the most lightweight solution possible, so if there is something lighter than a magnetic current sensor (and able to measure up to 30 maybe 50 amps) then I'm all ears.

    Thanks
  • SeekerSeeker Posts: 58
    edited 2011-11-03 16:44
    Progress wrote: »
    Oh sorry I forgot to mention the most important thing heh, I'm trying to measure the instantaneous current. The idea is to have the most lightweight solution possible, so if there is something lighter than a magnetic current sensor (and able to measure up to 30 maybe 50 amps) then I'm all ears.

    Thanks

    And that brings up another question... voltage. Is this an 11 volt lipo in a small 'setting' or a supply line to a 30 amp AC drive controller?
  • SeekerSeeker Posts: 58
    edited 2011-11-03 16:58
    I only ask because I have had to measure both types using DIY sensors.... HVAC systems, and my own 11 volt lipo helicopters. And there are trade offs depending on size, demands, and expectations.

    And by DIY I mean with available parts that you have to buy and connect together, or rip an old coil from many different broken electronic toys and devices, wrap some wire around it and make your own sensor, and use a few other parts to condition the signal for ADC or PWM conversion. Both are DIY... just different tools and costs.
  • ProgressProgress Posts: 11
    edited 2011-11-03 17:11
    Yup, I am using a 11 v lipo in a "small setting". I might go up to a max of 5cell tho so 18.5v
  • SeekerSeeker Posts: 58
    edited 2011-11-03 18:03
    Progress wrote: »
    Yup, I am using a 11 v lipo in a "small setting". I might go up to a max of 5cell tho so 18.5v

    Are you trying to measure motor current (brushed/brushless) or overall current for the total setup? And is this just for testing purposes, or for long term monitoring?

    I am actually working on a project now, 3cell, 4 - EDF VTOL quad that has both an R/C and drone mode. Of course I am using 4 - 2100mah 30C in parallel. Not a huge amount of power, but one mistake.... and I might get hurt! Or a total of about 2 weeks of pay would become a memory with a bad math equation to blame.

    I am thinking of a test type probe (which is the easiest, and I can alter others I already have), or a long term 'to measure and log to find problems later type of sensor'. I really want both. But I think time is going to limit me to immediate testing until I need monitoring for faults in a motor or ESC.

    Both use the same idea, but are designed differently. You wanted light weight, so I am guessing you want flight sensors. So knowing if it is a single motor/esc, 2, or 3, or everything including CPU is the next question. And is this for a test setting (prototype) or a final solution?

    Fun stuff. I love this part of the design.... the decision making over the finer details. It takes the most time, but it is the most fun.
  • SeekerSeeker Posts: 58
    edited 2011-11-03 19:10
    For the people that might wonder what the various options are (in theory, and practice. But it is an older article) look at

    http://www.sensorsmag.com/sensors/electric-magnetic/the-universal-current-sensor-1029

    It explains the basics very well, even if a bit verbose. ;)

    Hey I had a quick look through the mental archives while I was cooking dinner. It was the first place I thought of while cutting onions. No insult to the article. I just needed a chopped onion when I was thinking about it.
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