Solid State Sensors CS Series

Current Sensors

54HoneywellSensingandControl11-800-537-6945USA1F1-815-235-6847International11-800-737-3360Canada

OPERATION

MICRO SWITCH CS series solid state cur-

rent sensors monitor either alternating

(AC) or direct (DC) current. This series

includes a wide assortment of devices

ranging from digital output current detec-

tors capable of sensing a few hundred

milliamps to linear sensors capable of

monitoring over one thousand amps. The

entire family of CS current sensors pro-

vides a means of accurate low-cost cur-

rent sensing.

Current sensors monitor current flow.

Digital sensors produce a digital output

signal. Linear sensors produce an analog

output signal. When these signals have

reached a predetermined level, the con-

trol system logic is instructed to perform a

function. The digital signal with its logic

level output may sound an alarm, start a

motor, open a valve, or shut down a

pump. The linear signal duplicates the

waveform of the current being sensed

and is ideal for use as a feedback element

to control a motor or regulate the amount

of work being done by a machine.

Some CS current sensors utilize a

through-hole design. This feature insures

that there will not be any DC insertion loss

in the conductor. In addition, the through-

hole design simplifies installation by elim-

inating the need for direct connection,

which minimizes energy dissipation, and

provides output isolation at no extra cost.

MICRO SWITCH CS through-hole current

sensors cannot be damaged by overcur-

rent.

Current sensing is accomplished by mea-

suring the magnetic field surrounding a

current-carrying conductor. The conduc-

tor is passed through the flux collector

which concentrates the magnetic field at

the sensing element. The magnetic field

is directly proportional to the current

passing through the conductor. Thus,

there is a direct relationship between the

output voltage of the current sensor and

the level of input current. The waveform of

this output voltage will track the waveform

of the measured current. The through-

hole design electrically isolates the sen-

sor and insures that it will not be damaged

by overcurrent or high voltage transients.

LINEAR CURRENT SENSORS

MICRO SWITCH CSL series linear current

sensors incorporate our 91SS12-2 and

SS94A1 linear output Hall effect transduc-

er (LOHET

). The sensing element is as-

sembled in a printed circuit board mount-

able housing. This housing is available in

four configurations (as shown in mount-

ing dimension Figures 1, 1a, 2, and 2a on

page 59). Normal mounting is with 0.375

inch long 4-40 screw and square nut (not

provided) inserted in the housing. The

combination of the sensor, flux collector,

and housing comprises the holder

assembly.

When sensing zero current the output

voltage of the current sensor is approxi-

mately equal to one half of the supply

voltage (Voffset – 0.5 Vcc). CS series lin-

ear current sensors will sense current in

both directions. Current flow in one direc-

tion will cause the output voltage to in-

crease from its offset value. Current flow

in the opposite direction will cause the

output voltage to decrease from its offset

value. The output voltage range is from

25% of the supply voltage to 75% of the

supply voltage (0.25 Vcc

0.75

Vcc).

While sensing either AC or DC current,

the linear output voltage will track the

waveform of the sensed current.

The output of these devices can be ad-

justed by varying the supply voltage, var-

ying the gap cut in the flux collector, or

increasing the number of turns of the con-

ductor passing through the center of the

flux collector. Devices on page 56 are

ratiometric.

ADJUSTABLE LINEAR CURRENT

SENSORS

MICRO SWITCH offers two families of lin-

ear current sensors with adjustable offset

voltage and sensitivity. Both families uti-

lize the previously described linear cur-

rent sensors mounted to a small printed

circuit board containing additional circui-

try. The adjustable feature enables the

user to define the exact range of oper-

ation. The offset voltage and sensitivity

are controlled by two trimpots soldered to

the printed circuit board. These sensors

are ratiometric.

DIGITAL CURRENT SENSORS

Each MICRO SWITCH CSD series digital

current sensor provides a logic level out-

put that changes from approximately Vcc

to 0.4 volts when the sensed current ex-

ceeds the operate point. Each digital sen-

sor will operate on AC or DC current, but

the output will turn off at every zero cross-

ing when sensing AC current.

Note: Operate and release currents are

specified in Amps-Peak. When monitor-

ing AC current using a digital sensor,

peak values should be used. Multiply the

RMS values by 1.414 to obtain the peak

value.

INDUSTRIAL OUTPUT CURRENT SEN-

SORS

Current sensors with industrial outputs

easily interface with programmable con-

trollers and other industrial control and

monitoring devices. They have 4 to 20 mA

or1to 5 VDC outputs and are packaged in

a low-cost open PC board configuration

or enclosed housings. These devices in-

clude a regulator. Therefore, they are not

ratiometric.

FEATURES

Digital or linear output

AC or DC current sensing

Through-hole design

Fast response time

Output voltage isolation from input

Minimum energy dissipation

Maximum current limited only by

conductor size

Adjustable performance and built-in

temperature compensation assures

reliable operation

Accurate, low cost sensing

Operating temperature range –25 to

APPLICATION

Variable speed motor controls

Automotive diagnostics (battery drain

detector)

Ground fault detectors

Motor overload protection

Current monitoring of electric welders

Energy management systems

Protection of power semiconductors

Control system diagnostics

Burnt-out light bulb detection

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Solid State Sensors CS Series

Current Sensors

Honeywell Sensing and Control11-800-537-6945 USA1F1-815-235-6847 International11-800-737-3360 Canada55

CATALOG NUMBER SYSTEM

PLEASE NOTE: This matrix is intended

only to aid you in identifying sensor cata-

log listings. It is not all-inclusive, and must

not be used to form new listings.

Example: CSLA1CD

CS Current Sensors

Linear L

Digital D

A1 Holder – 9SS

A2 Holder – SS9

B1 9SS DC-DC Ratiometric Unregulated

B2 9SS AC-DC Ratiometric Unregulated

B3 9SS AC-AC Ratiometric Unregulated

B4 ALC DC-DC Ratiometric Unregulated

B5 ALC AC-DC Ratiometric Unregulated

B6 ALC AC-AC Ratiometric Unregulated

C2 9SS AC-DC 1-5 Unregulated

E1 9SS DC-DC 1-5 V Regulated

E2 9SS AC-DC 1-5 V Regulated

E3 9SS AC-AC 1-5 V Regulated

E4 ALC DC-DC 1-5 V Regulated

E5 ALC AC-DC 1-5 V Regulated

E6 ALC AC-AC 1-5 V Regulated

F1 9SS DC-DC 4-20 mA Regulated

F2 9SS AC-DC 4-20 mA Regulated

F3 9SS AC-AC 4-20 mA Regulated

F4 ALC DC-DC 4-20 mA Regulated

F5 ALC AC-DC 4-20 mA Regulated

F6 ALC AC-AC 4-20 mA Regulated

A PCB Small Holder

B PCB Medium Holder

C Small Holder

D Medium Holder

E Large Holder

F PCB Large Holder

G Small Sidemount

H Plastic Housing Small Opening

J Plastic Housing Large Opening

K Metal Housing

L PCB Small Sidemount

If 9SS If SS9ALC

DC-DC Other

A 14 Amps C 24

B 16 D 57 72

C 33 E 92

D 57 F 114 125

E 75 G 148 150

F 100 H 245 235

G 120 J 250 310

H 150 K 400

J 225 L 490 550

K 325 M 604 765

L 625 N 950

P 1208

Q 1500

HOW TO INTERPRET CURRENT SENSOR SPECIFICATIONS

The following definitions will help the user

understand the characteristics of the

MICRO SWITCH current sensor line.

Adjustable Operating Range — The ad-

justable linear current sensors give the

user the option of changing the sensitivity

according to the maximum sensed cur-

rent of the application. The on-board sen-

sitivity adjustment allows the user to alter

the amplification of the Hall effect sensor,

thereby adjusting the amount of sensed

current needed to achieve maximum out-

put voltage.

Example Vcc − 12V

Voffset −Vcc/2 − 6V

Vo maximum −(75%)Vcc − 9V

Vspan available −3V

Assume a current maximum of 45 amps is

determined. The user would then apply

45 amps through the toroid and adjust the

sensitivity where indicated until a 9 volt

output is achieved. The sensitivity is then

determined as (3V)/(45A) − 67mV/A. This

design allows for maximum sensor flex-

ibility.

For best results, choose a sensor to oper-

ate toward its maximum operate range.

Increased amplification occurs when the

sensor is adjusted toward its minimum

operate range. Any circuit noise is also

amplified.

Offset Shift — The offset shift refers to the

effect of temperature on the offset volt-

age. It is defined as a percentage of read-

ing per degree Celsius. Example: Offset

voltage is 6.0V at 25°C. The offset shift is

±0.05%/°C. Therefore, the offset voltage

at 35°C is 6.0V ± (0.05%/°C) (6.0V) (10°C)

− 6.0V ± 0.03V. The offset shift due to

temperature increases as the device is

operated toward the temperature ex-

tremes.

Offset Voltage — The offset voltage is the

voltage output when no current is flowing

through the current carrying conductor.

This is also known as the null voltage.

Operate Current — The operate current

is the level of current required to cause a

change in logic state from the state at no

current flow. For example, the logic out-

put is high at no current flow. When the

current level is increased to the operate

point, the logic output goes low.

Ratiometric — Characteristics vary in

proportion to supply voltage.

Release Current — The release current

is the level of current required to cause a

change in logic state as the current flow

decreases from the operate point.

Response Time (linear) — Measured

from the time the input current reaches

90% of its full scale value to the time when

the sensor output reaches 90% of final

value. This assumes rise time of 1 micro-

second or less on input.

Response Time (digital) — The length of

time it takes the output to switch to within

ten percent of the supply voltage from the

negative supply after the rated operate

point is reached on the input. Measured

time will vary proportionally with the over-

drive current.

Sensed Current (Amps Peak) — The

SS94A1 and 91SS12-2 linear output Hall

effect sensors have a maximum sensed

range. The toroid (flux collector) in each

holder assembly has a gap in which the

sensor is placed. By varying the width of

the gap (lg), the level of current that pro-

duces the amount of gauss necessary to

saturate the sensor is varied. In other

words, the maximum/minimum output of

the Hall element will always be obtained

at rated gauss excitation. The current lev-

el needed to achieve that maximum/mini-

mum output depends on the width of the

gap in the flux collector. Max sensed cur-

rent is also affected by number of times

sensed current wire is looped thru sensor

hole. If max sensed current is 100 amps

and current wire is looped thru hole twice,

max sensed current drops to 50 amps.

Looped 4 times it drops to 25 amps, 5

times to 20 amps.

Sensitivity – The change in sensor out-

put to 1 amp change in input. Units are in

units/NI where N is number of times

sensed current wire is looped thru sensor

hole. For example, if sensed current wire

is looped thru hole twice then sensitivity

doubles; looped thru 3 times, sensitivity

triples, etc.

Temperature Range — The –25° to

+85°C specified is the operating temper-

ature range that the current sensor has

been rated. The performance specifica-

tions are not considered to be valid out-

side the specified temperature range.

Current

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