Lilco logo 413x119

UK Design and manufacture of wideband current measurement transformers and wideband voltage measurement transformers

A series of low cost unterminated current transformers designed for the measurement of rectangular and sinusoidal currents containing harmonic components below 100 kHz in applications where economy is an important feature. In these models sensitivity can be customised by choice of secondary resistor and pulse characteristics enhanced by the application of a DC bias.

K2151 Current transformer.

Internal diameter of 4.5mm, Sensitivity from 0.1 to 1.0 V/A and current measurement to 5A rms

K2151 500x275
K2151 323x250

TYPICAL VALUES

Model Number

Secondary Resistor

Sensitivity

Rectangular Pulse

Sinewave

Irms

50/60Hz

Amps

Peak Pulse

Current

Amps

Unit Price GBP

Droop

Rise

Time

I-t no

Bias

I-t with

bias

3dB bandwidth

Ipeak/f

A/Hz

 

Ohms

V/A

%/ms

us

mAs

mAs

lf Hz

hf kHz

A/Hz

Amps

Amps

1

100

K2151

100

0.10

1.0

3

15

60

1.3

150

0.19

5

500

3.80

2.30

1000

1.0

8.0

3

2.2

10

8

150

0.033

1

50

K2154 and K2157 Current transformers

 

Internal diameter of 5.5 mm, Sensitivity from 0.1 to 1 V/A and current measurement to 20A rms

K2154 499x331
K2154 347x280

TYPICAL VALUES

Model Number

Secondary Resistor

Sensitivity

Rectangular Pulse

Sinewave

Irms

50/60Hz

Amps

Peak Pulse

Current

Amps

Unit Price GBP

Droop

Rise

Time

I-t no

Bias

I-t with

bias

3dB bandwidth

Ipeak/f

A/Hz

 

Ohms

V/A

%/ms

us

mAs

mAs

lf Hz

hf kHz

A/Hz

Amps

Amps

1

100

K2154

100

0.10

0.77

3

38

190

1.4

130

0.48

10

1000

5.30

3.20

1000

1.0

5.5

3

5.0

20

8

130

0.062

2

100

K2157

200

0.10

0.37

7

58

300

0.7

60

1.3

20

1000

5.60

3.30

2000

1.0

1.8

4

9.4

45

4

100

0.15

5

100

K2161 and K2164 Current transformers

Internal diameter of 9.5 mm, Sensitivity from 0.1 to 1 V/A and current measurement to 40A rms

K2161 295x300
K2161 500x256

TYPICAL VALUES

Model Number

Secondary Resistor

Sensitivity

Rectangular Pulse

Sinewave

Irms

50/60Hz

Amps

Peak Pulse

Current

Amps

Unit Price GBP

Droop

Rise

Time

I-t no

Bias

I-t with

bias

3dB bandwidth

Ipeak/f

A/Hz

 

Ohms

V/A

%/ms

us

mAs

mAs

lf Hz

hf kHz

A/Hz

Amps

Amps

1

100

K2161

100

0.10

0.25

4

110

350

0.5

130

1.3

20

1000

6.50

3.90

1000

1.0

1.5

2.5

15

50

3.5

160

0.19

7

100

K2164

200

0.10

0.15

8

160

430

0.17

65

2.1

40

1000

7.40

4.40

2000

1.0

0.83

8

28

90

1.7

65

0.35

12

100

Notes on operation of these current transformers

Load resistors should be non inductive and selected to carry the intended currents, and be of appropriate precision

Current ratio is determined from the relationship : Output Sensitivity = Load resistor value / ratio.

 

The current ratio accuracy with 0.1 V/A sensitivity is +/-0.5%

 

Sensitivity can be adjusted by changing the load resistor value.

 

I-t capability can be enhanced using a favourable DC bias. The bias used in the above tables  was 100mA via a 1R resistor.

 

DC primary saturation current is typically between 100mA and 200mA

Updated    October 2017