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Solar Electronics - Current and Injection Probes

Current Probes: Current probes required by various EMI specifications (such as MIL-STD-461/2) are toroidal transformers designed to measure RF currents on active power lines or other conductors.

Injection Probes: Specifications require the injection of large high frequency currents into cable bundles and individual wires, using inserted secondary toroidal transformers placed around the conductors being tested.

EFT Generator, Burst generator, eft burst generator, electircal spike, lightning stroke, powerfail, ringwave
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9335-2 Multiple Impedeance Coupling Device

Impedance matching injection probe






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Description

The unique winding arrangement of this impedance matching probe* provides step-up or stepdown ratios with respect to either: 1) the source impedance of the connected generator, when used for injection, or 2) the load impedance of the connected receiver,when used for reception. This results in maximum power transfer into or out of the transformer winding formed by the cable bundle passing through the window.

The Type 9335-2 Multiple Impedance Coupling Device provides:
1:1.0 voltage or current transfer
1:1.5 voltage step-up or current step-down
2:1.0 voltage step-down or current step-up
1:3.0 voltage step-up or current step-down

These ratios are selected by connecting to one of the four BNC connectors on the side of the Type 9335-2.

Figure 1 shows a family of curves representing the transfer functions for each connector port when the device is used as an injection probe.

Through connector port selection, the open circuit voltage or short circuit current can be adjusted for maximum transfer of energy. This is especially useful as an accessory to the Model 9354-1 Universal Transient Pulse Generator with its differing source impedances, enabling it to meet various open circuit voltage, and short circuit current requirements.

Application

Various EMI specifications require the injection of high level voltage or current pulses and the reception of low level voltage or current emissions using a toroidal transformer or coupling device around the interconnecting conductors of the subsystems/equipment being tested.

The Type 9335-2 Multiple Impedance Coupling Device is a split toroid, designed as a versatile impedance matching transformer used in conjuction with a generator as an injection probe for conducted susceptibility tests such as methods CS10 and CS11 of MIL-STD-462, Notice 5; CS116 of MIL-STD-462D; DO-160C, Section 22, Figure 22-12; and other specifications.

INJECTION - High power transient generators with source impedances from 0.25 ohm; to 50 ohm can use this probe to deliver high peak voltage or high current pulses into the wires or cables passing through the window of the device.

Calibration

For proper calibration of current probes, a special test fixture must be used to maintain a 50 ohm characteristic impedance for the test signal as it passes through the window of the probe.

The design of the Type 9357-1 Calibration Fixture was carefully tailored to provide a 50 ohm characteristic impedance based on the specific dimensions of the Type 9335-2. The fixture maintains a low standing wave ratio from 10 KHz to 10 MHz in a 50 ohm circuit.

* We refer to this unique device as the Knoller Probe, since it is the brainchild of Hank Knoller, an EMC engineer with more than forty years experience in the design and application of equipment for EMI testing.

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RFI / EMI Current Probes and Injection Probes






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Current Probes

Current probes required by various EMI specifications (such as MIL-STD-461/2) are toroidal transformers designed to measure r.f. currents on active power lines or other conductors.

Description

Direct connection to the conductor carrying EMI current is not necessary, since the probe may be opened for insertion of the conductor into the window of the toroid and then closed again to form a toroidal transformer with the conductor acting as a one-turn primary.

A correction factor graph is provided to convert measured microvolts to EMI microamperes.When the EMI current is measured in dB above one microvolt as indicated on a conventional EMI meter, the correction factor will convert the measurement to dB above one microampere. The correction factor is the inverse of the transfer impedance, Zt. Each probe is shipped with a graph of the correction factor versus frequency, keyed to the serial number on the probe.

Under certain conditions, a current probe can be used to inject low level r.f. signals into individual wires or cable bundles. Ask our engineers for advice in the use of current probes for this purpose. Some current probes can be easily damaged or are otherwise unsuitable for this application.

Application

A current probe is used as a "pick-up" device for measuring r.f. current in single conductors or cable bundles when connected to the 50 ohm input of a radio frequency interference measuring receiver or spectrum analyzer.

Injection Probes

Specifications require the injection of large high frequency currents into cable bundles and individual wires, using inserted secondary toroidal transformers placed around the conductors being tested.

Description

Bulk Current Injection Probes are available in two styles:

1. Fixed window style where the wire(s) under test must be passed through the window.

2. A split toroidal design where the probe can be opened up and clamped over the wire(s) under test.

Each probe is calibrated for insertion loss and transfer impedance in a test fixture designed for the particular window size.This fixture provides a signal path with a low Voltage Standing Wave Ratio. A typical fixture is Solar Type 9125-1, used for probes with 32 to 44 mm diameter windows. Ask for details on this and other test fixtures.

Injection probes available at the time of this printing are described later in this section. Development of new styles is ongoing. If a probe meeting your requirements is not found on the list, send us details and we will satisfy your need.

Application

High power r.f. amplifiers with 50 ohm output impedance are used to deliver voltage to the injection probe. The wire or cable through the window of the probe acts as a secondary of the toroidal transformers. This test method is intended to be used instead of earlier methods, such as CS-01, CS-02, and RS-02 of MIL-STD-461.

Technical Information

Current probes used as receptors are known as �inserted primary toroidal transformers� for connection to EMI receivers.

Injection probes which deliver high r.f. currents into wires through the window are called �inserted secondary toroidal transformers�.

The maximum voltage carried on wires through the window is limited only by the insulation of the wires. Maximum primary current in the wires through the window of current probes is listed on the table below (symbol lp).

The signal input to injection probes is rated in watts from the signal source as indicated in the table on the following page.

Development is continuing on new and useful probes, both current measuring �sensor�probes and high wattage injection probes.The following is a partial list. As time goes on, the list will grow. If you do not see what you need, just ask.


CLAMP-ON CURRENT PROBES

MAXIMUM PRI. (lp) CURRENT, AMPS
Solar
Type No.
Window
Diameter
Nominal
ZT Ohmns
DC to 60 Hz 400 Hz RF (CW) PULSE FREQUENCY
RANGE
9124-1N 1.25" (32.0 mm) 0.001 200 70 50 5000 1 KHz -200 MHz
9204-1 1.25" (32.0 mm) 0.33 350 350 50 100 1 KHz - 8 MHz
9205-1 1.25" (32.0 mm) 0.33 800 800 50 100 20 Hz - 8 MHz
9118-1 1.25" (32.0 mm) 0.10 350 150 22 500 500 Hz -200 MHz
9134-1 1.25" (32.0 mm) 0.70 500 400 5 100 20 Hz -100 MHz
6741-1 1.25" (32.0 mm) 0.70 350 225 5 100 10 KHz -100 MHz
9206-1 1.25" (32.0 mm) 1.0 350 350 4.2 100 10 KHz -150 MHz
9207-1 1.25" (32.0 mm) 1.0 800 450 4.2 100 20 Hz -150 MHz
9208-1 1.25" (32.0 mm) 1.0 350 350 100 200 10 KHz - 30 MHz
9209-1 1.25" (32.0 mm) 1.0 800 800 100 200 20 Hz - 30 MHz
9145-1 1.25" (32.0 mm) 5 350 350 42 100 10 KHz -150 MHz
9119-1N 1.25" (32.0 mm) 1-7 200 200 40 70 1 MHz - 1.2 GHz
9123-1N 1.25" (32.0 mm) 1-5 200 200 40 60 10 KHz -500 MHz
9115-1N 1.25" (32.0 mm) 10 250 250 50 100 3 MHz-200 MHz
9214-1 1.25" (32.0 mm) 5 600 600 21 200 20 Hz -150 MHz
9215-1N 1.25" (32.0 mm) 1-5 400 350 40 100 20 Hz -500 MHz
9231-1 1.25" (32.0 mm) .010 300 200 7 3000 1 KHz -200 MHz
9219-1N 1.25" (32.0 mm) .025 400 300 150 200 20 Hz - 20 MHz
9242-1 1.25" (32.0 mm) .025 400 80 35 100 20 Hz - 20 MHz
9250-1N 1.25" (32.0 mm) .10 200 200 10 200 10 KHz -450 MHz
9136-1N 2.62" (67.0 mm) 5 350 350 100 200 10 KHz -100 MHz
9249-1N 2.62" (67.0 mm) 8 350 350 60 200 10 KHz -300 MHz
9256-1N 2.62" (67.0 mm) 2 350 350 200 200 10 KHz - 30 MHz
9257-1N 2.62" (67.0 mm) 2 500 500 200 200 20 Hz - 30 MHz
9258-1N 2.62" (67.0 mm) 5 500 500 100 200 20 Hz -100 MHz
9260-1N 2.62" (67.0 mm) 2 350 75 2.6 100 10 KHz -200 MHz
9261-1N 2.62" (67.0 mm) 2 500 500 2.6 100 20 Hz -200 MHz
9262-1N 2.62" (67.0 mm) .03 350 150 80 200 100 KHz - 100MHz
9263-1N 2.62" (67.0 mm) .3 500 500 80 200 20 Hz -100 MHz
9301-1N 2.62" (67.0 mm) 8 500 500 60 200 20 Hz -500 MHz
9302-1N 2.62" (67.0 mm) .001 400 70 100 500 20 Hz -100 MHz
9303-1N 2.62" (67.0 mm) .001 500 200 100 5000 20 Hz -100 MHz
9304-1N 2.62" (67.0 mm) 1 350 350 2.3 200 10 KHz -200 MHz
9305-1N 2.62" (67.0 mm) 1 500 500 2.3 200 20 Hz -200 MHz
9306-1N 2.62" (67.0 mm) .005 200 65 60 5000 10 KHz -100 MHz
9307-1N 2.62" (67.0 mm) .005 300 300 60 5000 20 Hz -100 MHz
9308-1N 2.62" (67.0 mm) .01 300 75 17 2000 10 KHz -200 MHz
9309-1N 2.62" (67.0 mm) .01 450 450 17 2000 20 Hz -200 MHz

FIXED WINDOW PROBES

MAXIMUM PRI. (lp) CURRENT, AMPS
Solar
Type No.
Window
Diameter
Nominal
ZT OHMS
DC to 60 Hz 400 Hz RF (CW) Pulse Frequency
Range
9218-1 .50" (12.7 mm) .1 10 10 8 100 10 KHz -250 MHz
9248-1 .50" (12.7 mm) 1 10 10 10 100 10 KHz - 50 MHz
9203-1 .50" (12.7 mm) 1 10 10 2.2 100 10 KHz -250 MHz
9211-1 .50" (12.7 mm) .5-3 10 10 5 100 1 MHz- 1 GHz
9202-1 .50" (12.7 mm) 5 10 10 10 100 10 KHz -250 MHz
9246-1 .50" (12.7 mm) .1 150 150 8 100 10 KHz -250 MHz
9253-1 .50" (12.7 mm) 1 150 150 65 100 20 Hz - 50 MHz
9245-1 .50" (12.7 mm) 1 150 150 3 100 10 KHz -300 MHz
9210-1 .50" (12.7 mm) .3-5 150 150 16 100 300 KHz -500 MHz
9212-1 .50" (12.7 mm) .3-4 150 150 30 100 1 MHz- 1 GHz
9244-1 .50" (12.7 mm) 5 150 150 13 100 10 KHz -600 MHz
9346-1 .50" (12.7 mm) 5 150 150 13 100 20 Hz -600 MHz

CLAMP-ON INJECTION PROBES

Solar
Type No.
Window
Diameter
Winding
Current
Rated
Watts
Insertion Loss
Under 6 dB
Insertion Loss
Under 10 dB
Insertion Loss
Under 15 dB
Insertion Loss
Under 20 dB
Frequency
Range
9108-1N 1.25" (32 mm) 10 50 - - 120 KHz - 70 MHz 60 KHz - 150 MHz 10 KHz - 200 MHz
9120-1N 1.25" (32 mm) 30 50 - 12 MHz - 600 MHz 7 MHz - 900 MHz 4 MHz - 1GHz 4 MHz - 1 GHz
9121-1N 1.25" (32 mm) 30 50 - 100 MHz - 550 MHz 50 MHz - 800 MHz 30 MHz - 1GHz 10 MHz - 1 GHz
9142-1N 1.50" (38 mm) 50 200 10 MHz - 350 MHz 5 MHz - 430 MHz 2.5 MHz - 500 MHz 1.5 MHz -500 MHz 2 MHz -500 MHz
9144-1N 1.50" (38 mm) 26 100 - 200 KHz - 8 MHz 70 KHz - 90 MHz 40 KHz -100 MHz 10 KHz -100 MHz
9217-1N 1.50" (38 mm) 26 100 800 KHz - 1.5 MHz 500 KHz - 40 MHz 250 KHz -100 MHz 150 KHz -100 MHz 10 KHz -100 MHz
9310-1N 2.62" (67 mm) 26 100 - 15 MHz - 450 MHz 800 MHz - 650MHz 4 MHz -800 MHz 5 MHz -800 MHz
9607-1N 1.25" (32 mm) 10 50 - 500 KHz - 1 MHz 200 KHz - 30 MHz 120 KHz -300 MHz 10 KHz -300 MHz
Injection probes can also be used as current probes. A correction factor graph and instructions for its use are supplied.

CALIBRATION FIXTURES

Note: Except for p/n 9125-1 and 9357-1, the probes are supported and centered in the fixture.

Solar
Part No.
DESCRIPTION
9125-1 For Injection Probes, 1.5" (32 mm - 44 mm) diameter window. 20 Hz to 500 MHz. Type BNC connectors.
9125-2 For Solar 9119-1N Probe and similar, 1.25" (32 mm) diameter window. 400 MHz to 3 GHz. Type N connectors.
9251-1 For Eaton, Stoddart and Solar Probes, 1.25" (32 mm) diameter window. 20 Hz to 500 MHz. Type BNC connectors.
9254-1 For Eaton, Stoddart and Solar Probes, 2.62" (66 mm) diameter window. 20 Hz to 500 MHz. Type N connectors.
9321-1 For Eaton, Stoddart and Solar Probes, 0.75" (19 mm) diameter window, totally enclosed. 20 Hz to 1.5 GHz. Type BNC connectors.
9330-1N For Eaton, Stoddart and Solar Probes, 1.25" (32 mm) diameter window, totally enclosed. 20 Hz 1.0 GHz. Type N connectors.
9357-1 Clam Shell Fixture for Solar 9335-2 Probe. 20 Hz to 100 MHz. Type BNC connectors.