Что такое asa using a curve tracer
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Что такое asa using a curve tracer

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Launched the release of a new model of curve tracer Assist-ASA

Curve tracer of voltmeter and impedance signatures Assist-ASA is a hardware-software complex designed for technical diagnosis and troubleshooting in electronic digital, digital-to-analogue and analogue circuits, modules and units using parametric method.

Assist-ASA has the possibility of troubleshooting (of microchips, transistors, capacitors, resistors etc.) on the board of unit under testing (here and after – UUT) without supplying it with feeding voltage.

Curve tracer can be used by staff without high qualification. It also provide conditions to make a repair of electronic modules quickly even if basic circuit diagrams are absent or not found.

Troubleshooting of UUT is performed with parametric method VI (UI, ASA) by measuring volt-ampere signatures and impedance characteristic in the check points of the malfunctioning electronic module and then compare data to the reference points.

Reference characteristics are measure on known-good circuit and are stored in files in PC. There is also a possibility to work without storing the reference data (using and applying the second probe in the same point on known-good board).

Assist-ASA operates with the characteristics presented in the form of graphical signatures and their corresponding numerical values (R is resistance, C is capacitance, U is voltage at the inflection point of the current-voltage characteristic). The criterion for the discrepancy of characteristics during automatic comparison is the excess of the threshold of tolerance of the measured R, C, U from the reference one. The threshold is set programmatically in percentage terms. For most cases, it is recommended to set the value of the limit deviation threshold at the level of 10–15%.

Сurve tracer Assist-ASA

Curve tracer Assist-ASA

Curve tracer of voltmeter and impedance signatures Assist-ASA is a hardware-software complex designed for technical diagnosis and troubleshooting in electronic digital, digital-to-analogue and analogue circuits, modules and units using parametric method.

Assist-ASA has the possibility of troubleshooting (of microchips, transistors, capacitors, resistors etc.) on the board of unit under testing (here and after – UUT) without supplying it with feeding voltage.

Curve tracer can be used by staff without high qualification. It also provide conditions to make a repair of electronic modules quickly even if basic circuit diagrams are absent or not found.

Troubleshooting of UUT is performed with parametric method VI (UI, ASA) by measuring volt-ampere signatures and impedance characteristic in the check points of the malfunctioning electronic module and then compare data to the reference points.

Reference characteristics are measure on known-good circuit and are stored in files in PC. There is also a possibility to work without storing the reference data (using and applying the second probe in the same point on known-good board).

Assist-ASA operates with the characteristics presented in the form of graphical signatures and their corresponding numerical values (R is resistance, C is capacitance, U is voltage at the inflection point of the current-voltage characteristic). The criterion for the discrepancy of characteristics during automatic comparison is the excess of the threshold of tolerance of the measured R, C, U from the reference one. The threshold is set programmatically in percentage terms. For most cases, it is recommended to set the value of the limit deviation threshold at the level of 10–15%.

The method allows you to get information in order to determine the faulty elements on the board as well as to find breaks and short circuits of the conductors of the printed circuit board.

The Assist-ASA consists of an analysis unit and two active probes (each of them is equipped with a contact needle and a micro-circuit). The USB analysis unit is connected to a control computer (laptop) with special software installed. Assist-ASA can be equipped with optional accessories.

Characteristic tracer has a range of advantages in comparison with its analogues:

— two channels and two modes of signature comparison (comparison to reference data and comparison to known-good module of the same type) on one screen;

— high level of automation during creation of signature data base;

— automatic identification of the quality of the contact of the probe’s needle with the board;

— automatic use of three different combinations of parameters of the probe signal during the measuring of the each signature;

— automatic identification of signatures correspondence with producing sound signal;

— the criterion of signatures correspondence is managed from the interface;

— one channel (measuring the current signature, recording it to a file, comparing the current signature with the reference one from the file);

— two channels (comparing the current signature with the signature of the known-good UUT)

from 5 Ohm to 10 MOhm,

with the discreteness 1Ohm (in the range from 5Ohm to 1 kOhm), 100 Ohm (5kOhm – 1 MOhm), 100kOhm (1MOhm – 10 MOhm)

from 2 pF to 1000 mkF,

with the discreteness 1 pF (in the range from 2 pF to 1 mkF), 1000 pF (1 mkF – 1000 mkF)

— analysis unit «Assist ASA»

— two active probes with markings

— set of maintenance documents

V-I Tester (aka ASA or Octopus or curve tracer)

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I want to build a simple V-I tester and based on this article (or this) I did this easy circuit: R1 = 560Ω
R2 = 100Ω
R3 = 1kΩ
where R1 and R2 is a voltage divider to set the \$V_<(DUT+V_)>=1VAC\$ and R3 limit the current in the Device Under Test. I used this transformer, with 6.3V, 10 VA output (is dual, but I use only one output). My question:

  1. If I change the voltage divider resistors to \$R_1=56Ω\$ and \$R_2= 10Ω\$ (especially), isn’t better? With 10Ω I will reduce the output impedance of the circuit that feed the DUT, thus I don’t load the source because it is in parallel to the \$R_3+R_\ge1000Ω\$ and then \$R_3+R_\gg R_1\$ , isn’t?
    BTW the current I draw is \$I =\frac\approx 100mA\$ and the output power is at the «safe» value of: \$6.3V\cdot100mA = 0.63VA\$
  2. With this voltage divider I have a voltage less than 1VAC across the DUT. The article says that I can test also Diode, Zener, etc. How is possible with this small voltage?

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asked Apr 21, 2022 at 15:09
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\$\begingroup\$ Just to say that R3 «limit» the current through device, but is also the «measure» sensor of this current. Point 2: diodes need only 0.7V . current is always «exp», and the scale doesn’t matter. You can’t determine the Zener point if the voltage is too low. \$\endgroup\$

Apr 21, 2022 at 17:15

\$\begingroup\$ Point 1: changing values is not really useful, because R3 limits the current. NB: adding a battery, one pot, and one resistor to control current, should also be used for testing and tracing curves of quasi any type of «transistor» . \$\endgroup\$

Apr 22, 2022 at 7:09

\$\begingroup\$ @Circuitfantasist — Divider R1- «R2 variable» only to limit the excursion of max voltage on DUT (some kind of current protection). For low current, it is enough and easy through R2. For high currents, a variable transformer (or a «fast» triangular voltage pulse with a low duty cycle) should be needed to adjust the voltage applied on DUT (as on a professional Curves-tracer), but with a scheme of «power» protection (so the calculation of v*i on the DUT is necessary to remain under Pmax) . \$\endgroup\$

Apr 22, 2022 at 18:19

\$\begingroup\$ @Circuitfantasist It is a very good exercise in a lab and helps to understand some drawing functions (mathematical with scope) and electronic characteristics of DUT. This simple circuit is very useful. I used this simple curve tracer about 55 years ago with my «own scope made» . and a professional tool Philips (radiomuseum.org/r/philips_transistor_curve_tracer_pm_6507.html) 5 years later at university. \$\endgroup\$

Apr 22, 2022 at 19:56

\$\begingroup\$ Right. I forget that the axes for the «tunnel» curve are reversed! I used only the load line for the curves of UJT (V vs i) . 🙁 \$\endgroup\$

“ASSIST–ASA” Curve Tracer

It is intended:
For finding faults in electronic boards and modules using parametric method (UI, ASA) and for measuring signatures of volt-ampere and impedance characteristics at reference points.

The tracer obtains data used to detect faulty components (microcircuits, transistors etc.) on a board without applying voltage to it. It also detects breaks and short circuits of conductors on a printed board. The device does not require highly qualified personnel. It is efficient to repair electronic boards when electrical circuit diagrams are not available.

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