Tracker-2800-2800S.pdf - 第21页

21 2-10 Smar t Tracker Active Range (STAR) feature The Tracker 2800 has a built- in operating feature called STAR ( S mart T rac ker A ctive R an ge). This important feature protects sensitive components from possib le e…

2-9 Four Basic Component Analog Signatures

All Tracker signatures are a composite of one or more of the four basic component signatures which

are: resistance, capacitance, inductance and semi-conductance. Refer to Fig 2-11. Each one of these

basic components responds differently to the Tracker 2800's test signal. Recognizing these four basic

unique signatures on the LCD display is one of the keys to successful ASA troubleshooting. When

components are connected together to form a circuit, the signature at each circuit node is a composite

of the basic component signatures in that circuit. For example, a circuit with both resistance and

capacitance will have a signature that combines the analog signatures of a resistor and capacitor. The

signature of a resistor is always indicated by a straight line at an angle from 0 to 90 degrees. The

signature of a capacitor is always in the form of a circle or ellipse shape. The signature of an inductor

is also a circle or ellipsoid shape that may also have internal resistance. Finally, the semiconductor

diode signature is always made up of two or more linear line segments that most of the time form an

approximate right angle. Semi-conductance signatures can show conduction in both forward and

reverse-bias. This will form a zener semiconductor pattern which will show both junctions.

Figure 2-11. Analog Signatures of the Four Basic Components

Resistance

Capacitance

Inductance

Semi-conductance

2-10 Smart Tracker Active Range (STAR) feature

The Tracker 2800 has a built-in operating feature called STAR (Smart Tracker Active Range). This

important feature protects sensitive components from possible exposure to excessive power (for

example, 15V and 10). The table 2-4 specifies the active and disabled voltage & resistance test range

combinations.

10 50 100 1k 5k 10k 50k 100k

200mV Enabled Enabled Enabled Enabled Enabled Enabled Enabled Enabled

3 V Disabled Enabled Enabled Enabled Enabled Enabled Enabled Enabled

5 V Disabled Enabled Enabled Enabled Enabled Enabled Enabled Enabled

10 V Disabled Enabled Enabled Enabled Enabled Enabled Enabled Enabled

15 V Disabled Disabled Disabled Enabled Enabled Enabled Enabled Enabled

20 V Disabled Disabled Disabled Disabled



Disabled Disabled



Enabled Enabled

Table 2-4. Valid Tracker 2800 Ranges (STAR)

To illustrate the STAR feature, do the following:

Select the 200mV, 10 range. This is a valid range shown by the LEDs being illuminated on the

200mV and 10 buttons.

Press the 5V button. Notice that the 5V LED is on and the resistance range changes to 50

automatically. The 5V at 10 range is disabled.

Now press the 15V button. Notice that the 1k resistance is automatically selected. The 15V at 50

range is disabled and the next valid resistance range was activated at the selected voltage.

2-11 DC Voltage Source

The built-in DC voltage source of the Tracker 2800 allows in-circuit testing of certain devices in their

active mode. In addition to using the red and black probes, the output of the DC voltage source is

connected to the control input of the device to be tested with the blue clip lead provided. The DC

voltage source has one positive DC output. Figure 2-12 shows how to connect the Tracker to the

device under test (a SCR is used in this example) using the DC voltage source.

Figure 2-12. Tracker 2800 DC Source Typical Setup

The DC Voltage Source output is set using the DC Level controls (indicated by arrows) on the LCD

touch screen. While in the power-up menu, press the DC button then use the  and  arrow buttons to

increase or decrease the output voltage. The voltage level will be displayed at the top of the display.

The level control varies the magnitude of output amplitude from zero to + 10 volts. Press the DC

button to return to the power-up menu.

The DC Voltage Source can be used to test gated devices such as SCRs, TRIACS, optocouplers and

relays. It can also be used “bias test” transistors by applying voltage to the base while monitoring the

collector-emitter signature with the Tracker. This test method works similar to the basic functions of a

curve tracer.

CAUTION

The device to be tested must have all power turned off and all high voltage capacitors discharged

before connecting the Tracker to the device. Failure to do so may cause damage to the Tracker and

void the warranty.

DC Level

controls