SP Series Application Manual SP S05M Series SP S05P Series Overview The SP Series is a closed-loop type and built-in bus bar-type current sensor. The rated current has variations o 6 A, 5 A, and 5 A, respectively. The mounting structure is the on-board type. Table : Outline o SP series Ta = 5 C Vcc = +5 V (Unless otherwise speciied) Series name SP series Model number SP S05M SP S05P Rated current 6 A, 5 A, 5 A 6 A, 5 A, 5 A Rated output voltage Vo 0. 65V Vo : オフセット電圧 Oset voltage (Standard: ( 標準.5 V).5V) Bus-bar-pin length 5.5 mm ± 0.5 mm rom stando.5 mm ± 0.5 mm rom stando Characteristics Built-in bus bar-type supply system o the current to be measured. The built-in bus bar can be selected rom turn to turns depending on the connection method. Closed-loop-type circuit coniguration. Output o on-board-type ormat with panel mounting structure. Single power-supply voltage o +5 V can be used. Output in the orm o voltage given as output voltage corresponding to the current to be measured. Very high accuracy output voltage o within ±.7%. (When measuring rated current, Ta = 5 C) Excellent output linearity o within ±0.%. di ast response: Step response (response speed ) o less than μs. dt Withstand voltage: AC 000 V or minute Satisies conormity saety standard. Use eneral purpose inverter / 4
UPS ormat SP S 05 Suix M: Bus-bar pin 5.5 mm P: Bus-bar pin.5 mm (Each dimension represents the length rom the stando) Power-supply voltage 05: +5 V Power-supply type S: Single power supply Rated current 006: 6 A 05: 5 A 05: 5 A Series name SP Standard connection diagram SP S05 / 4
プラス電流方向 Plus current ( ラベルに記載 direction ) (Speciied on the label) N 6 5 4 Vout 受信回路の入力へ To nput o Receiving circuit RL は turn ターン ND 受信回路のNDへ To ND o Receiving circuit ig. -: SPS05: Standard connection diagram o -turn bus-bar プラス電流方向 Plus current ( ラベルに記載 direction ) (Speciied on the label) N 6 5 4 は turn ターン Vout ND To nput o Receiving circuit 受信回路の入力へ RL 受信回路のNDへ To ND o Receiving circuit ig. -: SPS05: Standard connection diagram o -turn bus-bar プラス電流方向 Plus current ( ラベルに記載 direction ) (Speciied on the label) N 6 5 4 は turn ターン Vout ND To nput o Receiving circuit 受信回路の入力へ RL 受信回路のNDへ To ND o Receiving circuit ig. -: SP S05 Standard connection diagram o -turn bus-bar / 4
Description o input/output terminals: SP D05 Table : Description o input/output terminals Terminal Terminal name Description Remarks number Bus bar 6 or one bus bar. 5 or one bus bar. 4 or one bus bar. 4-5 - 6-7 Vout Output terminal. * Outputs voltage corresponding to the current to be measured. 8 ND round terminal. Power supply +5 V and the ground or the output voltage. 9 Power supply terminal. nput between the terminal and ND. * V 0. 65 Vo (Unit: V) :Current to be measured (A) :Rated current (A) Vo:Oset voltage (V) The standard value is Vo. 5V typ. 4 / 4
Description o basic characteristics The SP Series current sensor is used or the measurement o 6 A ~ 5 A class current and outputs the voltage corresponding to the current to be measured rom the output terminal. The internal structure is composed o a core (a magnet) penetrating three independent bus bars and an electronic circuit. The electronic circuit is composed o a negative eedback coil constituting a closed loop and a phase compensation circuit or stable operation o the ampliier and the closed loop. A single power-supply voltage o +5 V can be used. The current to be measured is passed through a bus bar o the sensor. The magnetic lux generated by the current to be measured converges to the built-in core (a magnet), and the built-in ampliier energizes the canceling current to the negative eedback coil in such a way that the generated magnetic lux becomes extremely small, i.e., approximately 0 tesla. That is, a current is supplied to the negative eedback coil so as to cancel the magnetic lux generated by the current to be measured. The magnetic lux o the core (a magnet) is proportional to (current) times (number o turns.) Let the number o turns o the negative eedback coil be N. Then, when three bus bars are used as one turn, the magnetic lux at the core (a magnet) is canceled and becomes nearly zero or the current o o the measured current passing through the negative eedback N coil. The current applied to the negative eedback coil canceling the magnetic lux is converted into voltage by the.5 V reerence dierential ampliier and is output rom the output terminal. n this case, thereore, the voltage corresponding to N o the measured current plus.5 V is output. When three bus bars are used as three independent turns, the magnetic lux at the core (a magnet) is canceled and becomes zero or N o the measured current passing through the negative eedback coil. Similarly, the current applied to the negative eedback coil canceling magnetic lux is converted to voltage by the.5 V reerence ampliier and is output rom the output terminal. A voltage corresponding to N o the measured current is output. A voltage with a positive polarity is output when the current to be measured is supplied in the direction o the arrow described in the main body. As described above, the sensitivity, (output voltage.5 V) / (current to be measured), o the closed-loop current sensor is proportional to (number o bus-bar turns)/(number o turns o the negative eedback coil) and is approximately determined by the number o turns o the coil and that o the bus bar. Thereore, it is little aected by luctuations in the sensitivity o the Hall element. The closed-loop SP Series current sensor can achieve a high accuracy o within ±.7% in the output and within ±0.% in the output linearity. This current sensor operates in a manner similar to that o a current transormer so that a sharp change in the current can be measured. When the current to be measured changes stepwise, high-speed response is possible. n act, when the current to be measured rises at the rate o 00 A/μs, the measured value reaches 90% o the target value within μs. The sensor has an on-board-type structure enabling attachment to a board, and the wiring to the power-supply terminal and the output terminal can be conigured in accordance with the pattern on the board. 5 / 4
Block diagram (+5 V single power-supply type) SP S05 電流通電部 Current supply part Current detection 電流検出部 part Ampliier 増幅部 part eedback 帰還部 part Current-voltage converter part 電流電圧変換部 +Vcc () D Plus current プラス電流方向 direction (Speciied ( on ラベルに記載 the label) ) N 6 5 4 - + D Oset adjusting オフセット調整部 part Vout ND N ig. : SP series: nternal block diagram Description o block diagram Current-lowing unit The current-lowing part passes the current to be measured through the bus bar built in the main body. Three bus bars are built in and are independent o each other. The three bus bars can be used as one-turn, two-turn, and three-turn bus bars by changing the wiring. The current to be measured is supplied to one bus bar to generate a magnetic lux in the built-in core. The magnetic lux generated by the current to be measured is concentrated on the core o high magnetic permeability. A Hall element, inserted in the core as a magnetic detection element, detects the magnetic lux o the core, and converts the lux into voltage. The bus bar generates heat due to its own resistance component (copper loss). Even when the ambient temperature is maximum, the maximum value o the current is determined in such a way that the temperature o the sensor does not exceed the speciied value. n addition to the copper loss o the bus bar, heat is generated owing to iron loss (core loss) o the core built into the sensor. Each loss varies depending on various conditions such as the magnitude, requency, and waveorm o the current to be measured. The loss increases with the eective current or with the dominant requency component o the current to be measured. When the current contains high-requency components other than those o the undamental wave, iron loss 6 / 4
urther increases. Thereore, conirmation using an actual current is necessary. Current-detection unit The current to be measured (primary input current) is passed through the bus bar. The generated magnetic lux is ocused by the core and applied to the magnetic-detection element (Hall element, ). When the wiring o the built-in bus bar is one turn, the magnetic lux to be generated in the core by the current to be measured is proportional to the current. On the other hand, approximately N o the measured current lows through the negative eedback coil and generates a magnetic lux in the direction opposite to the lux generated by the measured current. Because the number o turns o the negative eedback coil is N, the magnetic lux o the core is canceled and becomes almost zero. The current lowing through this negative eedback coil is sent to the current-voltage converter. The magnetic detection element () detects a net minute magnetic lux comprising a small current canceled by the current to be measured and the current o the negative eedback coil and converts it into voltage. The converted voltage is sent to the ampliier. When the bus bars are used with two-turn wiring, the current o the negative eedback coil canceling the magnetic lux generated by the measured current becomes N o the measured current. When the bus bars are used with three-turn wiring, the current o the negative eedback coil is proportional to mechanism. N o the measured current because o the same The current o the negative eedback coil is sent to the current-voltage conversion circuit, converted into voltage, and then becomes the output voltage. eedback section o ampliier unit The ampliier circuit ampliies the output voltage o the magnetic-detection element (). The current rom the ampliier circuit is sent to the eedback circuit. The eedback circuit provides current to the eedback coil. As a result, it constitutes a closed loop consisting o the magnetic-detection element ampliier circuit eedback circuit negative eedback coil core magnetic lux (magnetic-detection element). See ig.. 7 / 4
A C A C Y A C Current to be measured 被測定電流 N Y A C + - Core コア Negative eedback coil 負帰還用巻線 n Nturns タ-ン N Y AC Y AC 電流電圧変換器 Current-voltage converter Output 出力端子 terminal V Vo 負荷抵抗 Load resistance ig. : Closed-loop block diagram (n the case o one-turn bus bar) The current to be measured,, is mostly canceled by the current lowing through the negative eedback coil,, and the remaining current Δ becomes a net minute current that excites the core. A C A is detected by the and is converted to voltage, The above-mentioned minute current generates a small magnetic lux, permeability. The small magnetic lux C this voltage is ampliied by and converted into currenty C, through the core o high magnetic A C. urthermore, A that lows through the negative eedback coil and becomes. When the number o turns o the negative eedback coil is N, the number o ampere turns is N. Thereore, as a result o subtracting N rom the current to be measured, the net minute current Δ that excites the core can be written as N Y A. Equation C 8 / 4
Y A C. Equation rom Equations and, thereore, the relationship between the output current is obtained as where N Y N Y C Y A. A C A C and the current to be measured, Equation Because μ o the closed-loop current sensor has a very large value, Equation 4 holds while maintaining high accuracy o the output current within ±.6%. (n the case o one-turn bus bar) Equation 4 N When the bus bars are wired with nbus n BUS turns, the output current becomes. N Current-voltage converter The current-voltage converter converts the current o the negative eedback coil into voltage. rom Equation 4, because is proportional to the current to be measured, voltage conversion o the current to be measured is accomplished by the voltage conversion o. Because the current to be measured lows in both plus and minus directions, the current-voltage converter provides oset voltage V o. That is, the current-voltage converter converts using Equation 5 and outputs the output voltage V rom the output terminal. V Vo, Equation 5 where Vo is the oset voltage (V) and is the gain (V/A) in the current-voltage converter. Equations 4 and 5 give the standard relationship between the current to be measured and the output voltage V, given by Equation 6. V V Vo Equation 6- N 0.65. V (n units o V) (Standard value), Equation 6-5 where is the rated current (A) and is the current to be measured (A). 9 / 4
Oset adjustment unit The oset voltage Vo is a reerence output voltage where the current to be measured is 0 A. or the SP Series, the standard value o the oset voltage is.5 A. The main origin o a possible deviation o the oset voltage rom the standard value o.5 A lies in the act that the, which is the magnetic sensing element, can have an oset voltage. The oset voltage o the is a minute voltage output even in the absence o applied magnetic lux. The minute output voltage generated by this oset voltage is the origin o the deviation o the oset voltage. n addition to the, deviation o the oset voltage can also be caused by the ampliier section. Beore the product is actually shipped, adjustment is made, using the oset-adjusting part, in such a way that the overall oset is comprehensively canceled out and alls within a predetermined deviation. Application プラス電流方向 ( ラベルに記載 ) Plus current direction (Speciied on the label) N 6 5 4 Vout 受信回路の入力へ To nput o receiving circuit Vout RL は turn ターン ND 受信回路のNDへ To ND o receiving circuit ig. 4: Application (n the case o one-turn bus bar) [Note] The application shown below is not within the assurance standard o the SP Series current sensor. n other words, the accuracy o the application and the perormance corresponding to the parameter values o the parts shown below are not guaranteed. Thereore, when selecting circuits and component parameters during the design o actual products, suicient evaluation based on careul consideration o saety and the stability o characteristics is necessary. Basic operation 0.65 This current sensor outputs the measured current as the output voltage ( V. 5V ) in units o V, where is the rated current (A) and.5 V is the standard value o the oset voltage. The load resistance RL is basically 0 / 4
standardized as 0 kω. The power supply o +5 V is required to have suicient capacity to supply the current o the negative eedback coil plus the current consumed by the sensor. Oset voltage The oset voltage Vo is the output voltage when the measured current is 0 A. Although the standard value o the oset voltage is.5 V, in the case o the SP series, it has a deviation o ±0.05 V to ±0.05 V (depending on the item). or the oset voltage o 0.05 V, when measuring the current near the rated current, it causes an error within ±.4%. The inluence o the oset voltage when measuring twice the rated current decreases and the error can be compressed to within ±.%. On the other hand, when measuring a current o hal the rated current, the error due to the oset voltage increases to a value within ±4.8%. n order to minimize the error, it is necessary to select a sensor with a rated current suitable or the measured current. a sensor with a rated current higher than necessary is selected, the measurement error due to the oset current increases. Output linearity The output linearity is the dierence between a straight line approximating the input/output characteristics o the sensor and the sensor output, and the ratio (%) o the dierence to the absolute value is deined as output linearity. The ormula or calculating the output linearity o the measurement point J in ig. 5 is L where J L 00 (%), Equation 7 J V O V O : Rated output voltage (V), : Dierence o sensor output voltage at measured current J J : Rated current (A), : Measured current at measurement point J (A). J rom approximate linear line (V), Output voltage Approximate linear line V O J : Measured point J J Measured current ig. 5: Output linearity / 4
Hysteresis error Hysteresis error is caused by the hysteresis characteristic o the core. When the current to be measured is increased rom 0 A to the rated current and then returned to 0 A, a maximum dierence o ±0.5 ma with respect to the original value arises in the output voltage. This dierence is called hysteresis error. When the current to be measured increases or decreases during operation, this hysteresis error occurs. The amount o error is related to the amount o change o the current to be measured. The hysteresis error becomes larger when the width o the change increases. / 4
Overall detection accuracy in TOTAL tt The overall detection accuracy o the current sensor is summarized in Tables 4 and 5. Table : SP Series: List o deviations determining the accuracy o the output current (Unless otherwise speciied) Ta = 5C No tem Symbol Standard value (max) Remarks SP006S05P SP006S05M SP05S05P SP05S05M SP05S05P SP05S05M Output voltage accuracy X Within ±0.0V When measuring rated current Deviation o oset Vo Within ±0.05V Within ±0.0V Within ±0.05V voltage Output linearity L Within ±0.% When measuring rated current 4 Hysteresis error V OH Within ±0.0005 V 5 Temperature coeicient o output TcVo ±0.0000 5 V/C Excluding TcVo voltage 6 Temperature TcVo -0 ~ +5C -0 ~ +5C -0 ~ +5C coeicient o oset ±0.006 V/C ±0.0006V/C ±0.0004 V/C voltage +5 ~ +85C +5 ~ +85C +5 ~ +85C ±0.0008 V/C ±0.000 V/C ±0.000 V/C / 4
() Overall detection accuracy or measurement o rated current Table 4 shows the overall detection accuracy when measuring the rated current, obtained rom all items in Table. Table4: Overall detection accuracy or measurement o rated current Ambient temperature SP006S05P SP006S05M Accuracy SP05S05P SP05S05M TOTAL 5C ±.8% ±.8% ±.8% -5C ±.0% ±5.4% ±4.% +85C ±0.0% ±5.% ±4.% SP05S05P SP05S05M. () Overall detection accuracy or measurement o hal the rated current Table 5 shows the overall detection accuracy when measuring the rated current Table 5: Overall detection accuracy or measuring hal the rated current Ambient temperature SP006S05P SP006S05M Accuracy SP05S05P SP05S05M TOTAL 5C ±9.9% ±5.% ±4.% -5C ±.9% ±.9% ±9.4% +85C ±5.7% ±.% ±8.6%, obtained rom all items in Table SP05S05P SP05S05M Power supply The plus and minus power supplies provide the current o the internal negative eedback coil in addition to the MAX current consumed by the sensor,. Thereore, suicient capability to supply current is required, including 000 various items, as shown in Equation 8. MAX Vo max 5 CC (A) Equation 8 000 RL CC :.5 ma type RL : Load resistance (Ω) Standard: 0 kω MAX : Maximum current to be measured (A) Vo max : Maximum output voltage (V) 4 / 4