Specifications and Guidelines
Circuit system Description
Tamura offers multiple current sensor options to meet application requirements: Open Loop or Linear type (magnetic proportionality); Closed Loop or Servo-type (magnetic balance); Flux-Gate (magnetic equilibrium).
Open loop
L**Series(** is Number)
If the current is applied to the cable, the magnetic field proportional to the current in surroundings of the cable is generated on Ampere's rule. The magnetic core is set in surroundings of the cable to improve the sensitivity. The Magnetic field is converted into the voltage by the linear type - hall element is placed in the gap of the magnetic core. But the output voltage of hall element is several tens of milli-volt, It enlarges it to the output voltage of the product specification (several volts) by the operational amplifier.
The sensor output voltage is linearly proportional to the magnetic flux generated by the measured current. In general, the open loop sensor is voltage output. The characteristic (accuracy, linearity, response, temperature property, and high-frequency current*1, etc.) of the current sensor is not a little better than that of other circuit methods because of the difference of the circuit configuration (magnetic circuit , magnetism-electric conversion and amplification of electrical circuit). However, the size can be reduced and it is lower -cost more than other circuit methods.
*1- We use silicon steel and permalloy in internal magnetic core of the open-loop sensors in order to improve the measurement possible current and hysteresis error. Therefore, at the frequency of the applied current exceeds more than several kHz, there is a possibility that the internal circuit may be damaged by the heat generation of the core loss.
Closed loop
S**Series(** is Number)
The closed loop type current sensor measures the applied current on the condition that the magnetic flux density in the magnetic core is extremely zero. Therefore, there is no influence on accuracy by the non-linearity and hysteresis in the core because the flux density in the magnetic core operates in the starting point of the B-H curve in the operation region*1. The characteristic of the closed loop type is better than the open loop type current sensor.
The addition of a secondary winding (1000-5000 turns) on the magnetic core allows feedback current to be supplied in opposition to measured current to compensate or cancel the magnetic flux generated by the measured current. The output of the closed loop sensor is a current output proportional to the measured current divided by the number of secondary winding turns*2.
*1-At the high-frequency current (1-2kHz or more) and the pulse current, current sensor should operate at ACCT (transformer) because the loop gain of the feedback control decreases. Under such a condition, the magnetic flux in the magnetic core is generated .
*2-Output current = (Primary current ) / (Secondary winding turns)
Fluxgate system
F**Series(** is Number)
The flux-gate current sensor replaces the Hall element with probe coil made of highly saturable material. The magnetic offset of the probe coil does not occur in order to be driven by high-frequency current. The flux-gate utilizes a magnetic balance system to achieve high accuracy, temperature stable current output typically converted to a voltage output with an internal high precision resistor.
According to UL508 standard
Tamura Corporation has received UL508 and CSA C22.2 No.14 certifications for the current sensors listed below.
Please refer to the PDF below for more details.
Application notes
General Considerations
- 1The sensor uses polar electronic components. When the polarity of the power supply is mistaken, the sensor is damaged.
- 2 Static electricity or excessive voltage can increase an offset voltage in the Hall element, and cause offset voltage to change. Please exercise care in handling and application.
- 3In order to prevent the influence of noise, the use of twisted cable or shielded cable for the output line is recommended.
- 4If using this device within a magnetic field generated by other devices, the specified accuracy may not be obtainable.
- 5 Our products (several models are excluded ) are adjusted with the trimming method by the measurement condition (Load resistance, Power supply voltage) of specification sheets.
Therefore, characteristics (Offset, Output, etc.) and its deviation may be changed in different circuit conditions from the measurement condition.
All change characteristic items are not indicated on specification sheets. - 6The performance of current sensors with through-hole (aperture) is dependent on the position of the primary conductor. Tamura specifications are based on a primary conductor completely filling the through-hole (aperture) area.
- 7The current sensor rated current in DC Amps.
- 8Please use mating connector with equivalent terminal plating material to insure proper operation and avoid possibility of ‘galvanic corrosion’.
- 9Please do not store in high-temperature and high-humidity storage environment.
Please use it after confirming soldering when it is kept for six months or more. (product soldered with substrate) - 10We recommend performing a zero offset adjustment by measuring the offset voltage at startup. In continuously operation for a few months, or at change of ambient temperature or humidity is large, we recommend regularly performing a zero offset adjustment at being idling (it is clear that the current is not apply).
- 11 The current sensor doesn't have built-in protection circuit (devices and fuses, etc.). As a failure mode of the sensor, there is a short circuit and open state. In the case of a short-circuit state, the abnormal temperature rise of the internal parts is assumed, and there is a possibility to smoke and to ignite. If it is used in safety critical circuit blocks, please take appropriate measures by protection devices, protection circuits, etc. For closed loop -type sensors and flux gate (closed loop type) sensors, the consumption current of the secondary power supply varies in proportion to the measurement current.
Open Loop
L**Series(** is Number)
- 1High frequency primary current may result in excessive heating in iron magnetic core and cause damage to internal circuitry; for high frequency applications select current sensor with ferrite core material.
- 2 If the measured current exceeds the rated current, magnetic core saturation will occur and the output voltage signal will not be linearly proportional to the measured current.
Closed Loop
S**Series(** is Number)
- 1For closed loop current sensors please insure the power supply voltage is balanced, symmetrical, and, applied simultaneously to avoid potential increase in DC offset error.
- 2 Maximum rated current measurement duration is time-dependent. Maximum rated current applied in excess of the time limit can result in damage to internal electronic circuitry; please consult Tamura for assistance.
- 3 When using a measurement resistor to convert current output to voltage output select a resistor with stable temperature characteristic to insure accuracy of the output voltage.
- 4Compensation current supplied to the secondary winding varies in proportion to the measured current based on the conversion ratio. (If/KN; KN=# secondary turns) Please insure the PSU has required current capacity to supply compensation current to the secondary winding.
Flux-Gate
F**Series(** is Number)
- 1Compensation current supplied to the secondary winding varies in proportion to the measured current. Please insure the PSU has required current capacity to supply compensation current to the secondary winding.
- 2There is 450kHz ripple voltage present on the output and reference output voltage signals . An external capacitor maybe added if necessary.
Methods of characterization and measurement
The specification characteristics are provided below. The characteristics were measured at 25°C and ±1% tolerance power supply conditions. Please note: Some models are defined under different measurement conditions; please review specification.
- 1Primary nominal current
The value of measured current guaranteed to maintain an output with the specified linearity and output temperature characteristics.
- 2Saturation current
The value of measured current which indicates an output with a greater than ±5% deviation from the theoretical output value.
- *L18P series, it is greater than 10% deviation.
- 3Rated output
The output voltage ( or current) at the measured primary nominal current.
- 4Offset output
The output voltage ( or current) at a measured current of 0A or at 0A after magnetic core demagnetization.
- 5Linearity
The linearity straight-line approximation is obtained by measurement of output voltage or output current at 4 points (25%,50%,75%,100%) of the rated current value. The output values are then rationalized to the rated current to determine the maximum error at each point.
- *About the model that doesn't apply to this regulations, the condition is described to the individual data sheet.
- 6di/dt Response Time
The response time is the time difference from 10% of the applied input step current to 90% of the sensor output signal.
Please note:The large current product and Closed - loop type current sensor, the response time is the time difference from 90% of the applied input step current to 90% of the sensor output signal. Because rise time of input step current to be late.
- 7Output temperature characteristics
The change rate of rated output which deducted the offset output is shown per 1 degrees C. The rated output at 25 degrees C is a standard value.
- 8Offset temperature characteristics
The change rate of offset output due to temperature change is shown per 1 degrees C. The output at 25 degrees C is a standard value.
- 9Hysteresis Error
It is difference value between the offset output and the output after cycling from 0A to rated current to 0A.
Tamura's current sensors for EU RoHS
We are working to environmentally relevant laws in EU (i.e. RoHS, REACH). And TAMUTA supply the current sensors that complied with EU RoHS(2011/65/EU, 2015/863/EU) to our customers.
If you need the certification of RoHS directive or the report of REACH SVHC , please contact distributor or sales office. In that case, please specify the product name. It is not possible to issue it by the product series name.
Prohibited Substances
| Material | Maximum levels |
|---|---|
| Cadmium (Cd) | < 100ppm |
| Lead (Pb) | < 1,000ppm |
| Mercury (Hg) | < 1,000ppm |
| Hexavalent chromium (Cr6＋) | < 1,000ppm |
| Polybrominated biphenyl (PBB) | < 1,000ppm |
| Polybrominated diphenyl ether (PBDE) | < 1,000ppm |
| Bis(2-ethylhexyl) phthalate (DEHP) | < 1,000ppm |
| Butyl benzyl phthalate (BBP) | < 1,000ppm |
| Dibutyl phthalate (DBP) | < 1,000ppm |
| Disobutyl phthalate (DIBP) | < 1,000ppm |
- *Prohibited substances and exceptions follow EU RoHS Directive
Objectives
All the current sensors of the catalog shown in the following correspond. Please make separate inquiries if there is not product name. In addition, neither the discontinued products nor Not-recommended for new design are described.
| Series name | Series name | Series name | Series name |
|---|---|---|---|
| F01PxxxS05L | L01ZxxxS05 | L18PxxxD15AHV | S21S180D15JN |
| F02PxxxS05L | L05Z800S15 | L31SxxxS05FS | S22PxxxS05(P)(M2) |
| F03PxxxS05L | L06PxxxS05 | L32SxxxS05(B)FS | S23P50/100D15(M1)(M2) |
| F23PxxxS05R | L07PxxxD15 | L34SxxxD15(T) | S27S300D15Y(M) |
| F26PxxxS05 | L07PxxxD15S | L37SxxxS05(M)(J) | S28S500D24Z(M)(J) |
| F26PxxxS05A | L07PxxxS05 | L37SxxxD15(M)(J) | S29S1T0D24Z(M)(J) |
| F26P150S12 | L08PxxxD15(W)(IPV)(IPVW) | L40SxxxD15(M)(J) | S30S2T0D24Z(M)(J) |
| L12P025D15 | L40SxxxD15C(M)(J) | S42S1T0D24Z(M)(J) | |
| LA17PxxxS05 | L18PxxxD15 | L51SxxxD15L(M)(J) | |
| LA37SxxxS05(M)(J) | L18PxxxD15-OP | L51SxxxD15(M)(J) | |
| LA37SxxxS05K(M)(J) | L18PxxxS05 | L51SxxxD15C(M)(J) | |
| L18PxxxS05R | L55SxxxD15 | ||
| L18PxxxS12 |
- *The symbol of primary nominal current is “xxx”. 3 digit.
Important Notices
- 1The content of this information is subject to change without prior notice for the purpose of improvements, etc. Ensure that you are in possession of the most up-to-date information when using this product.
- 2This product is intended to be used in general electronics applications (electric home appliances, business equipment, information equipment, communication terminal equipment, measuring devices, industrial equipment, and so on). This product is neither intended nor warranted for use in following equipment or devices:
Special application (such as for medical devices, transportation equipment, traffic signal control equipment, fire and crime prevention equipment, aeronautics and space devices, nuclear power control, fuel control, in-vehicle equipment, safety devices, and so on) in which extremely high quality and high reliability is required, or if the malfunction or failures of product could be cause loss of human life, bodily injury.
Tamura Corporation shall not be held responsible for any damage incurred by customers or any third party when products are used in special application, unless specifically permitted in this document. - 3Tamura Corporation constantly strives to improve quality and reliability, but malfunction or failures are bound to occur with some probability in current sensor. To ensure that failures do not cause accidents resulting in injury or death, fire accidents, social damage, and so on, users are to thoroughly verify the safety of their designs in devices and/or systems.
- 4The operation examples and circuit examples shown in this information are for reference purposes only, and Tamura Corporation disclaims all responsibility for any violations of industrial property rights, intellectual property rights and any other rights owned by Tamura Corporation or third parties that these may entail.
- 5The circuit examples and part constants listed in these specifications are provided as reference for the verification of characteristics. The user is to perform design, verification, and judgment under his or her own responsibility, taking into account the various conditions.
- 6The products are designed for use in environments where consumer electronics are commonly used. It is not designed for use in special environments such as listed below, and if such use is considered, the user is to perform thorough safety and reliability checks under his/her responsibility.
- Use in liquids such as water, oil, chemical solutions, or organic solvents, and use in locations where the product will be exposed to such liquids.
- Use that involves exposure to direct sunlight, outdoor exposure, or dusty conditions.
- Use in locations where corrosive gases such as sea winds, Cl2, H2S, NH3, SO2, or NO2, are present. (Some product improves durability)
- Use in environments with strong static electricity or electromagnetic radiation.
- Use that involves placing inflammable material next to the product.
- Use of this product either sealed with a resin filling or coated with resin.
- Use of water or a water soluble detergent for flux cleaning.
- Use in locations where condensation is liable to occur.
- 7This product is not designed to resist radiation.
- 8Do not use or otherwise make available the TAMURA products or the technology described in this document for any military purposes, including without limitation, for the design, development, use, stockpiling or manufacturing of mass destruction weapons (e.g. nuclear, chemical, or biological weapons or missile technology products). When exporting and re-exporting the products or technology described in this document, you should comply with the applicable export control laws and regulations and follow the procedures required by such laws and regulations including, without limitation, Japan -Foreign Exchange and Foreign Trade Control Law and U.S.- Export Administration Regulations. The TAMURA products and related technology should not be used for or incorporated into any products or systems whose manufacture, use, or sale is prohibited under any applicable domestic or foreign laws or regulations.
- 9Please contact your TAMURA sales office for details as to environmental matters such as the RoHS compatibility of Product. Please use TAMURA products in compliance with all applicable laws and regulations that regulate the inclusion or use of controlled substances, including without limitation, the EU RoHS Directive. TAMURA assumes no liability for damages or losses occurring as a result of your noncompliance with applicable laws and regulations.
- 10TAMURA assumes no liability for damages or losses incurred by you or third parties as a result of unauthorized use of TAMURA products.
- 11This document and any information herein may not be reproduced in whole or in part without prior written permission from TAMURA.
Search for Products
Search by Keywords