|
CTHT Series
Current Transformers, High Frequency
Features:
• Low cost encapsulated transformer
• Designed for use over a wide frequency range
• Sensitivity can be set to match your specific requirements
• Can be provided with installed primary for easy PCB installation
• Other configurations available upon request - Contact Precision |
Current transformers (CT’s), like traditional transformers, convert voltages and currents based on their
turns ratio. The most important relationship for CT's is primary amp-turns equaling secondary
amp-turns Ip, Np = Is, Ns). Usually, CT's use a customer supplied single turn primary through the
center to carry the large circuit current and convert them to low current output. An appropriate turns
ratio and terminating resistor are selected to supply a voltage (proportional to the monitored current)
for the monitoring circuit.
The CT benefits include safety agency isolation and isolation required by circuit needs. High current is
difficult to monitor directly. Proper use of a CT transforms high current to easily monitored low current.
 |
| Figure 1 |
Precision Model Number |
Figure # |
|
A
MAX |
B
MAX |
C
MAX |
D
DIA NOM |
E
MIN |
F
NOM |
G
MIN |
H
MIN |
CTHT-17100 |
1 |
mm |
17.5 |
9.65 |
20.6 |
0.79 |
3.81 |
12.7 |
4.57 |
0.38 |
|
|
in |
0.690 |
0.380 |
0.810 |
0.031 |
0.15 |
0.500 |
0.180 |
0.015 |
Precision
Part Number |
Turn |
Inductance
mHy (Min) |
DCR
Ohms (Max) |
Input
Ip (Max) |
Rb**
Ohms |
CTHT-17100-0500 |
50 |
5 |
0.5 |
90 |
50 |
CTHT-17100-1000 |
100 |
20 |
1.4 |
90 |
100 |
CTHT-17100-1500 |
150 |
45 |
3 |
90 |
150 |
CTHT-17100-2000 |
200 |
80 |
4.5 |
90 |
200 |
CTHT-17100-3000 |
300 |
180 |
11 |
90 |
300 |
CTHT-17100-4000 |
400 |
320 |
18 |
90 |
400 |
CTHT-17100-5000 |
500 |
500 |
30 |
90 |
500 |
CTHT-17100-7500 |
750 |
1150 |
50 |
90 |
750 |
** Burden resistor value that will deliver 1 volt per amp with a single turn primary. (See design below for examples of other
Rb values)
Step 1:
To match your monitoring circuitry to a specific CT, you need to know the CT characteristics in
relationship to input current and frequency range. The primary relationship you will be working with
is Ip Np=Is Ns. To assist with choosing Rb, see graphs below. Lower or higher Rb values can be used
for your specific requirements. Contact a Precision engineer for assistance (See buttons below).
Note: All results shown assume a square waveform for the current, where Ton=0.5T
Primary
|
Secondary |
|
|
|
| Application Circuit |
Step 2:
If you would like further information for your specific requirements, please select a link below -
Click to contact Precision, Inc.
Call the Precision Engineering Help Line 800-749-3677 |
