Email: Telephone: USA +650-802-8292

Hall Magnetic Sensors
Magnetic Field
Electric Current
Angle & Position

Measurement Instruments
Electric Current
Magnetic Field
Magnetic Field Mapper
Magnetic Susceptibility

Fiber- Optic Links

Permanent Magnets

Electromagnets & Coils

Current Leads, HTS

Electromagnet Power Supplies

Particle Beam Diagnostics

Particle Beam Transport & Accelerators

• Special Sale Offers
• Discontinued Products



Conference Schedule
News Items
About GMW
Contact Information
Employment at GMW
VAC DC-AC Current Probes, Panel Mount,  
4640 and 4644 Series  

VAC 4640 and 4644 Series closed- loop current probes offer:

  • Low offset and gain errors, low temperature drift, excellent long-term stability
  • Low power consumption due to PWM compensation current driver stage
  • Wide measuring range up to 2500 A
  • Excellent dynamic properties (rise time, pulse response) due to a low winding capacity of the compensation current winding

DS600 DS2000

VAC 4644-X052


VAC 4640-X152

Specifications - 4644 Series
  4644-X052 4644-X054
 Primary Current, rms  TA=70°C  500A  700A
 TA=105°C  200A  250A
 Primary Current, Peak TA=70°C to
 ±700A  ±1250A
 Turns Ratio  1:2000  1:3000
 Sensitivity  0.500mA/A  0.333mA/A
 Measuring Accuracy
 (-40 to +85°C)
 Supply Voltage  ±12 to 15V
 Offset Current  <0.1mA
 Linearity  <0.1%
 Frequency  DC to 50kHz
 Delay Time  <1µs
 Operating Temperature  -40 to +85°C
 Aperture  13 x 30mm
 Dimensions (W x H x D)  56 x 56 x 26mm
Specifications - 4640 Series
 Primary Current, rms  TA=85°C  1000A
 Primary Current, Peak  TA=25°C  ±2500A
 TA=85°C  ±2150A
 Turns Ratio  1:5000
 Sensitivity  0.200mA/A
 Measuring Accuracy
 (-40 to +85°C)
 Supply Voltage  ±24V
 Offset Current  <0.1mA
 Linearity  <0.1%
 Frequency  DC to 100kHz
 Delay Time  <1µs
 Operating Temperature  -40 to +105°C
 Aperture  40mm square
 Dimensions (W x H x D)  110 x 94 x 27mm
LEM and VAC Panel Mount with Aperture, Comparison
LEM Part Number VAC Part Number, T60404-4640 Series Notes
LF 1005-S or LF 1010-S X100 +/-15V connector pinout differences
LF 1005-S/SP variant X101 +/-15V, JST BVH-21T-P1.1
LF 1005-S/SP22 X102 +/-15V, connector pinout differences
LF 1005-S or LF 1010-S X150 +/-24V, connector pinout differences
LF 1005-S/SP variant X151 +/24V, JST BVH-21T-P1.1
LF 1005-S/SP22 X152 +/-24V, connector pinout differences
Note: The 4640 series is a form factor compatible drop-in replacement for the LF 1005-S. The only exception is differences in connector pinout. Versions of the VAC 1000A may exist that are pinout compatible.
LEM Part Number VAC Part Number, T60404-4644 Series Notes
LAC 300-S/SP1 /SP5* X052 Drop-in placement
LAC 300-S/SP1 /SP5* X053 Drop-in placement
None X054  
LAC 300-S/SP2* X056 Drop-in placement
LAC 300-S/SP3 /SP4* X060 Drop-in placement
Some current ranges do not match exactly. Connector pinouts are the same between VAC and LEM. Connector call-out on data sheet is different but might be compatible regardless. All conversion ratios and form-factors are the matched.


Operating Principle
Closed-loop or zero-flux current probes have high linearity and excellent frequency response from dc. The current IP to be measured is magnetically coupled to the compensation current through a soft magnetic core. The magnetic flux of this core is measured by a magnetic field detector and controlled to zero by the electronics, generating a compensation current, IS, in the compensation winding. This current is proportional to the primary current, IP. VAC magnetic field detector reduces the offset voltage, temperature and time drift commonly associated with Hall effect probes.

Last updated on 23 July, 2018
  Tel: + 650-802-8292    Fax: + 650-802-8298
955 Industrial Road, San Carlos, CA 94070, USA