PC Mount Current Shunts Suppliers

[TechGuy]

Hi,

I am looking for a US supplier(s) that provides current shunts that can be mounted on a PCB.


Thanks,
TechGuy

 

[otherside]

For how much current ? you can use a miliohm resistor for a shuft for currents < 20A, more than that you're looking for big stuff.

Digikey and Farnell have quite a large collection of both.

 

[TechGuy]

I was looking for a shunt in the 50A range. If I recall correctly pretty much all of the resistors in the milliohm range are wirewound and have inductance. I am looking to use shunts since the don't have any measurable inductance.

I was thinking about fabricating my own using stainless foil and soldering copper terminals on (dip stainless in flux, scratch SS foil to remove oxide layer, and solder away). This will probably work for a one-off project.

 

[RCBandwidth]

Try Allegro

Thes are quite nice..linear hall effect current sensors.


http://www.allegromicro.com/sf/0750/index.asp

 

[otherside]

Excellent Device!!!!

 

[Eva]

Inductance is not such a bad thing if the intended purpose of the resistor is plain current sensing. Note that the effects of the zero introduced by the series inductance in the sense signal are easily cancelled by applying a suitable pole with a plain RC filter.

However, things are not so easy when the inductive resistor is in series with the drain or the emitter of a MOSFET or IGBT, and included in the gate drive loop, or when the resistor is part of the output stage of a class AB amplifier.

 

[AndrewT]

Hi,
are we seriously discussing 50A measurement techniques for on PCB currents?

Is that continuous, peak or transient? or not at all?

 

[TechGuy]

>EVA: However, things are not so easy when the inductive resistor is in series with the drain or the emitter of a MOSFET or IGBT

Indeed, that is why I want to avoid the inductance.

>Hi, are we seriously discussing 50A measurement techniques for on PCB currents?

Indeed I am. All large current connections will be backed with heavy gauge copper wire or with a bus to handle the high current loads. I've already done some investigation on the issues with PCBs and large current loads.


> AndrewT : Is that continuous, peak or transient? or not at all?

Transient.

 

[poobah]

Tech guy,

Check:

www.mouser.com

"current sense(ing) resistor" & "current shunt" should get you some hits. They have nice 4 legged Kelvin connections and all. And, they are essentially non-inductive.

 

[AndrewT]

Hi,

All large current connections will be backed with heavy gauge copper wire or with a bus to handle the high current

and you still want to bring these high transient currents on to the PCB.

Surely you should be investigating tapping into your bus and bringing the measurment currents on to the PCB.