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Questions tagged [test]

A definitive procedure that produces a test result.

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votes
1answer
244 views

Continuity testing - Why does swapping DMM probes give differing results?

Continuity query - Can anyone explain this? Circuit is a simple 12v DC, wired as follows -battery pos to bulb to spst switch back to battery earth. Testing with DMM in the dedicated audible ...
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0answers
10 views

What's the best dielectric breakdown test sequence for a DPST switch?

Please could you help me to check my understanding of dielectric breakdown testing? I’m only a humble mechanical engineer so I’m a bit outside my comfort zone. A product requires dielectric ...
1
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1answer
129 views

How to test a capacitor?

I've got a big 560 uF, 400 V capacitor and I've tested it with a meter and the capacitance is within spec, same the ESR and it has a vloss of 0.8%. So all seems fine but then I came across this video ...
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1answer
124 views

Is there a good way to test your schematic before buying the parts and building it?

I'm trying to design a BMS that can handle 12 cells, be powered either with a isolated dc-dc converter or the batteries themselves and uses active balancing, but I'm not sure if my design will work:
3
votes
3answers
113 views

Should you Megger test transformers?

I have heard people say you shouldn’t Megger test transformers because the high voltages used might cause insulation between windings and between windings and the core to breakdown. Is this true? ...
0
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4answers
140 views

Temporary but hands-free JTAG/SWD connection

I have a PCB that will have very little clearance on both sides so that putting a normal Cortex SWD .50 spacing connecter is too big. However, I'd still like to have the option of connecting via SWD ...
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3answers
77 views

Power Supply Earth for Bench Testing

I work in a typical electronics lab, with resistive earth mats, ESD straps and isolated DC power supplies to test prototype PCBs. I prefer not to use the power supply earth-ground, and to leave the ...
3
votes
3answers
3k views

Applying load when testing battery voltage

Why do we need to apply a load to a battery, when testing its voltage? I've been testing battery capacity so far using a multimeter and just connecting the probes to the positive and negative side of ...
4
votes
1answer
387 views

CMRR test methodology and effect of open loop gain

I am trying to test the CMRR of opamp and so measuring offset variation across Common mode range in unity gain mode. I have gone through many articles on CMRR measurement. All those are suggesting a ...
2
votes
2answers
491 views

How do we test and determine if a USB cable+connector is version 2, 3.0 or 3.1?

How do we test and determine if a USB cable+connector is version 2, 3.0 or 3.1, without using port, PC and/or having data transfer but instead with basic physics tests e.g. using multimeter?
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1answer
204 views

Build In Self Test LCD

I've recently been trying to get a custom LCD (ET101005DSAK0) connected to an Embedded System on Module however without any success. When debugging why the LCD is not working I wanted to make use of ...
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2answers
355 views

How to test a TRIAC with just a digital multimeter and no external circuit

I need to fix an electric kettle and would like to test the health of the TRIAC BTA20. How would you test this component health with a digital multimeter - without any extra components and ideally ...
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1answer
75 views

Electronically verify whether cable is connected to RJ45 connector

Background: I have a device that interfaces with a motor controller over RS-485 via an RJ45 socket. Currently, the port is a standard 4x2 RJ45 connector with the RS-485 using pins 2 and 7 ...
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2answers
71 views

Can I connect 10 AWG wire carrying up to 25 amps to 10 parallel 1 ohm 10 watt resistors?

I am trying to measure the charge capacity of some LTO battery cells. To do this I want to discharge each battery cell from 2.5 V to 1.7 V. I am going to measure and log the current over the discharge ...
0
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2answers
68 views

Quality Control Tests for hardware

We are in the process of creating a quality assurance & control department at work. I need to define different tests for the hardware that we make. The devices are composed of multiple pcbs, with ...
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2answers
46 views

DC test equipment to see voltage extremes? [closed]

I want to experiment with magnets and coils to produce voltage. I need test equipment to find the highest positive voltages and the lowest negative voltages obtained during tests. My needle driven ...
3
votes
1answer
2k views

Test circuit for EU1640BCH12T / R Water proof ultrasonic sensors with Arduino?

I have EU1640BCH12T/R waterproof ultrasonic sensors, which I have got from this link. These are standalone raw sensors without breakout board and not a module like HC-SR04. Being a new electronics ...
12
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3answers
41k views

What is Full form of hFE of a digital multimeter?

In digital multimeter, there is a transistor-check function, and there is a term hFE. I do-not know how-to use-it, however, different Websites say it is a measurement transistor's gain ("the ratio of ...
2
votes
1answer
114 views

Amateur radio practice exam question

The question is as follows: An interfering signal from a transmitter is found to have a frequency of 57 MHz (TV Channel 2 is 54 - 60 MHz). This signal could be the: And the options are as follows: ...
2
votes
2answers
1k views

Test a transistor with a multimeter

I used the guide at https://vetco.net/blog/test-a-transistor-with-a-multimeter/2017-05-04-12-25-37-07 to test a transistor with my DMM. The NPN transistor I used to test is the "mospec tip130 No11D" ...
14
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1answer
1k views

Amateur radio practice exam question about voltage drop

So the question is as follows: ...
0
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2answers
236 views

X2 capacitor. Test if failed open

I am looking at a small board in a paper shredder (it does not work). If I apply AC power and measure AC voltage across the X2 capacitor (I think it acts as a voltage dropper for the low voltage ...
-1
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1answer
85 views

How to test a lithium battery? [closed]

I ordered some lithium batteries (like this) I'm planning to test the specs like -Maximum Continuous Discharge Current -PCM Discharge Cut-Off Voltage -PCM High Temperature Cut-Off In what other ...
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0answers
49 views

Suggestions for switching 800VDC converter on/off

I'm stress testing(turning them on-off with load every 300 seconds for 1-2 weeks) the components that we are willing to use. have tested several battery chargers with AC input with using a timer relay ...
4
votes
3answers
784 views

How to test for USB dropouts on STM32F?

I've got a devices that is really strange, it drops USB periodically. By periodically I mean on a weekly (or biweekly) basis. By dropping out I mean windows loses the handle to the driver. Dropouts a ...
3
votes
1answer
186 views

Giant pogo pin or spring probe pin for registration during electrical test

Solved: if you search for "GP-2 PCB Board Umbrella Shape 5.3mm Tip Testing Probe Pins Receptacles" you will find these probes! Thanks for the help! I am designing an electrical test fixture, and I ...
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votes
3answers
125 views

Simplest/Cheapest Way to Create 4.5A Test-Load for 12Vdc Step-Down Regulator

I'm looking for the simplest/cheapest (but safe!) way to build a 4.5A test-load for an LMR14050-based 24Vdc to 12Vdc/5A step-down voltage regulator circuit. LMR14050 Datasheet Circuit Schematics ...
1
vote
1answer
103 views

Potentiometer Range in Speaker Frequency Response Curves

In several speaker spec sheets from CUI a frequency response curve is given, such as in the CLS0231MA-1: Notice the two y-axes: one for the potentiometer (0 dB to 50 dB) and one for the DUT (0 dB to ...
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4answers
5k views

Testing graphic LCD without code and wiring

I am using a KS0108 compatible graphic LCD (JHD12864E). I was wondering if there is a method to see if the lcd is working or not with a simple test. I tried sticking 5 volt between vcc and ground but ...
9
votes
1answer
917 views

Verowire woes - how to reliably solder it?

I'm using Verowire (wiring pencil, Road Runner, you name it) quite often to contact test points on my board to make them accessible for measurements (oscilloscope probe, multimeter clamp ...) Image ...
0
votes
1answer
98 views

How to simulate ~1ms long power interruption

I am looking to test an embedded system for its behavior during power interruption soon after power on. The system is supplied with 15V DC power with a steady state draw of <...
-1
votes
1answer
35 views

Motor drive IC test [closed]

I have placed an order for a PCB where i am using two vnh7100as ICs to run two motors. I need to send the PCB makers a test file to test the ICs before putting them on. I have no idea what to send ...
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0answers
45 views

Is there an easy way to provoke soft errors?

So I'm mainly involved in writing firmware for industrial sensors which are expected to be very robust. One of the things you have to face are random errors everywhere, especially in ICs outside of ...
0
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1answer
129 views

CE certification

One of the required CE test technical files is "Test Reports". This document has to be provided to the test agency. Does anyone know what data should be included in this document? Here are the ...
1
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3answers
63 views

Noise from test pins on signal lines?

Are test pins on sensitive signal lines likely to cause problems? For example, if there is a test pin sticking up from the board on a line going to a 20 bit ADC is there a danger of increasing the ...
4
votes
2answers
301 views

Detachable “debug” portion of PCB?

I'm trying to add "optional" debugging test points to an existing, very dense 4 Layer PCB design (signal - GND - PWR - signal). I'd like to change the existing PCB as little as possible. My idea was ...
2
votes
1answer
102 views

Low volume mixed signal electronics production (hardware test, calibration, flashing) automation [closed]

I am designing a mixed-signal board with microcontroller that will need flash memory programming for its firmware, (self-)testing, and documentation for the final production steps. I know there is a ...
12
votes
4answers
26k views

How to test a crystal resonator in board?

I have 2 quartz crystal resonators in my pcb board: 32.768 kHz & 20 MHz. They are connected to a Freescale MC12311 transceiver IC, which has an HCS08 micro-controller embedded in it. I want to ...
0
votes
1answer
791 views

How to test a laptop keyboard from its ribbon cable

Is there a way to test a laptop keyboard from at its ribbon cable, fully disconnected from the motherboard? Some kind of switch continuity or something along those lines that would indicate whether a ...
0
votes
1answer
41 views

What is the relevancy between the actual full load current value (test result) and the supposedly corresponding values from industry standards?

I work on evaluating a motor problem. If I am given an actual current at 100% full load, how does an industry standard value become relevant? I have an example to illustrate the point I am trying to ...
7
votes
2answers
673 views

Testing an old Geiger tube?

I have an old Soviet personal radiation dosimeter that I broke as a kid by dropping it into water. I opened it up a while ago and the electronics in there were quite simple - mainly a ~10cm Geiger ...
6
votes
3answers
1k views

How low an insulation resistance is too low for a residential electrical system?

I have had occasion recently to test the wiring of a residential building for damage from a lightning strike. I opened all the breakers, removed all the loads, opened the panel, and meggered each hot ...
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1answer
84 views

Resistance tester

I would need to create a simple tester with battery supply that compares resistance of specific wire with reference (approximately 4 ohms) and determines if the wanted resistance is in desired range. ...
0
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0answers
327 views

How to do insulation resistance measurement on a SMPS

Can anyone explain how to measure the insulation resistance of an isolated SMPS PCB? Is it correct to tie ACL and ACN and apply one terminal there, and the second terminal goes to the ground of the ...
0
votes
1answer
114 views

How can I properly test compatibility of a replacement led on a pcb?

I am looking to replace an led on this board, but I am unsure of what this current led's specs are in terms of what amperage and voltage are used by the led. I am curious what ways I can test to make ...
0
votes
2answers
154 views

led analyser for pcb functional test [closed]

i'm supposed to work on a project that consists on creating a led analyser to test PCB (functional test) they want me to create a system that can measure the color (R,G,B) and the luminous intensity ...
0
votes
1answer
71 views

Is it important to consider channel bandwidth of the signal to measure cable path loss for RF testing?

I am performing some RF tests for 802.11 and measuring path loss of the RF test setup, it has a mix of PSK & OFDM signals. I see the norm is to use a Continuous Wave signal to perform RF path loss,...
0
votes
1answer
110 views

Need Test jig for pass transistors

I am trying to find a schematic for a test jig. I have quite a few 2N5886 and MJ15003 TO3 transistors that I purchased and would like to make sure they meet specs. Short of building a separate ...
0
votes
1answer
195 views

Test an LCD for missing segments without looking at the screen? [closed]

I have a product with an LCD screen that sometimes fails with missing segments. I will test the product for a long time to replicate the failure. I will test many at once. I don't want to sit watching ...
1
vote
1answer
96 views

Field tests for veryfying stator core laminations loose in 3-phase, 3000 HP motor

We have a 4000 V, 3-phase, 366 A, 3575 rpm, 3000 HP induction motor that is making a modulated buzzing noise. The vibration in the horizontal planes of both bearing housings has increase from 0.1 IPS-...