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Questions tagged [testing]

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0answers
69 views

Darlington Transistor TIP142 same type but different values

I have a bunch of Darlington NPN Transistors TIP142 that are removed from two separate identical boards. The 1st one have the TO−218 CASE (left side of the image) and the 2nd the TO−247 CASE (right ...
1
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1answer
63 views

Is there a variable forward voltage diode-like device or circuit construction?

I need to make a test PCB for an LED drive circuit that can drive a variety of different single LEDs. The forward voltage (Vf) of the LED could be anywhere from ~2.2V up to ~6.5V. I'd like the test ...
4
votes
1answer
64 views

What are the tradition ways to signify/advertise that a potentially dangerous long-running test is in progress? [closed]

I frequently need to run long-term tests which have some potential for damage or harm if e.g. someone disturbs the test apparatus without being aware that it's running a test. Say for example ...
0
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2answers
91 views

Is diode with forward voltage ~0.15v faulty?

I tested a diode model SB360 PFS which it showed about 0.15 forward voltage. The reverse voltage is zero. Looking the diode specification I read that Vf is 0.49v to 0.68v. So my question is if this ...
1
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1answer
54 views

Switching Mode Power Supply Fluctuating Output

I designed a switching mode power supply using LNK-562, I share the circuit schematic below. Note that NTC, fuse, and the input filter inductor is replaced with shorts in the real circuits. I am ...
0
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2answers
82 views

How to tell if a capacitor is still good?

I was replacing a 400v 120uf capacitor in a power supply (ac 120v-19v DC 4.62 amps) well I was a dumb ass and stuck in backwards somehow. I tested the dc out end while it was still plugged in and ...
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0answers
44 views

Circuit testbench nailbed: how to test the pots?

Imagine I make an analog circuit, lets say a guitar pedal circuit (in a PCB of course). How can I test (automatically if possible) the potentiometers functionality, when testing in a nailbed ...
1
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1answer
113 views

How to test a MOV with no visible damage

As far as i know cumulative degradation occurs in a MOV when multiple surges appears in a circuit, A way to minimize this degradation is having multiple MOVs in parallel. This kind of damage can be ...
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3answers
50 views

Testing a thyristor

I have a very large high voltage device that a friend asked me to take a look at. It has a bunch of BIG thyristor packages (Semikron, SKKT 106/18 E, Dual Thyristor Module, 600A 1800V). I'm testing ...
2
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0answers
38 views

Testing eurorack input protection

I'm building a eurorack synth module, and I'm about to do the final tests on the design to make sure that the module cannot be destroyed (electronically, using what's available in the rack, so ...
15
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3answers
268 views

Puff of smoke in air. 3 different PCBs. PCB has ghosts?

Yes, that is a haiku.  (EDIT: fixed it... it is now actually a Haiku) No I'm not smiling. I'm doing some standard testing; seeing what happens when one of the two power rails gets shorted to GND on ...
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1answer
28 views

IEC 61952 Clause 11.1 Electrical Type Test

Where can I find the acceptance criteria for the Electrical Type Tests? Specifically, where is the Dry lightning impulse withstand voltage test and the Wet power-frequency test in the IEC 61952 Ed 2.0 ...
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2answers
110 views

How to test a DMX splitter

This question is related to the DMX splitter I'm building and shown in Prototyping a DMX splitter. However, for testing a different question is appropriate. I never really tested a hardware device, ...
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2answers
51 views

Help Shielding RF Anechoic Chamber - FM Stations

a collegue and I acquired a surplus small anechoic chamber (8 ft x 8 ft) for making some pre compliance test measurements, and we're running into the issue of FM Stations being only attenuated around ...
0
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1answer
40 views

How does Return/Insertion loss work for wireless devices if there’s no cable?

I understand return loss is the ratio of how much signal is reflected in a transmission line. But for wireless devices there is no cable. So how is this measured? So is the impedance mismatch for ...
0
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1answer
102 views

Power supply testing using dummy loads

I am busy thinking of how to test a power supply i am designing and came across an article which discussed using an electronic load to test the supply. I will not have access to an electronic load and ...
0
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1answer
72 views

dBmi Meaning in Testing

I'm having trouble making sense out of this requirement, in terms of how to test for it. I have a specification stating that for an RF power level measured in dBmi (let's call that power level S ...
0
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1answer
109 views

How to test 3528 smd LED

Using my DMM and the diode selector, the SMDs 3528 in a brand new Led bulb does not light. I used this method to test the classic "round" leds but in this case it does not work. What seems to be wrong ...
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2answers
132 views

MCU overheating

INTRODUCTION I've designed a custom board featuring a SAME54N20 MCU. This is the third board I assembled but I still haven't got any to work: I didn't get the first board to connect to my PC. My ...
1
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1answer
65 views

How to perform conducted emissions testing for electric generator?

I am doing pre-compliance EMC testing on an electric generator. The standard I am reading explains how to test devices that get power from mains, but it doesn't explain the testing procedure for a ...
2
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1answer
141 views

PCB Design Verification

I have been designing and prototyping a PCB for the last couple of months. I'm at the point where I'm extensively testing these boards before going into production. I have come across multiple ...
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2answers
125 views

ESD/EMI Design for CE, Recommendation seems wrong from test lab

I have designed a product for a customer, that now needs to pass UL/FCC/CE Testing, It passed UL & FCC but failed CE for both 8kv ESD and EMI. The Chinese test lab my client went through sent me ...
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1answer
69 views

What are the maintenance steps for PCBs? [closed]

If I have a multimeter that can measure current, voltage, capacitors, resistors, ..etc., how can I detect the damaged component(s) in a PCB? I try to visually detect if there are any damaged ...
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4answers
90 views

Stress testing a PCB’s current handling capability?

I’ve produced a simple unregulated power supply PCB, consisting of: AC input terminals Fuse 4 rectifier diodes Filter/smoothing capacitors DC output terminals Only when the PCBs arrived did I get ...
2
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2answers
99 views

How can I build a battery load tester that switches between 0.8 and 2.0 ohms? [closed]

I would like to build a load tester that switches: 2 seconds at 2.0 ohms and 1 second at 0.8 ohms and back to 2.0 ohms to repeat. I gather that I can have a circuit with two resistors and a switch ...
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2answers
47 views

What is the difference between load testing and discharging a LiPo?

I would like to test max discharge rates for 1S (200 mAh) LiPo's. But I can see three ways of doing it: Using a charger, discharge at highest rate and see how high the battery goes. Using a resistor (...
0
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1answer
114 views

How to test phone vibrator motor?

I have a phone vibrator motor that I want to check. This is what it looks like: And here is the schematic from the service manual: The motor is not connected to the circuit. It is by itself as seen ...
1
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1answer
164 views

Test point map for BBC micro:bit

Does anyone have a map of the test points on the BBC micro:bit? Specifically, I'd like to connect a scope to the lines from the nRF51's UART to the USB chip, which the published schematic suggests ...
0
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1answer
40 views

Testing a I/V stage using function generator

I created a I/V stage with amplifier for my DAC project. An excerpt of the circuit can be seen in the attached picture in the "Device under test" part. The DAC has a 3.9mA pp current output, which I ...
0
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1answer
48 views

Over voltage, over current and surge testing

I used a TI reference designto prototype a 120VAC to 5VDC 2A power supply on a PCB and it's been working fine for a couple of months. I want to run some basic tests to see if the PCB is safe under ...
0
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1answer
44 views

Are there disadvantages to this method of testing building wiring after a lightning strike?

A lightning strike can damage wiring in a building. Specifically it can damage the insulation on the conductors, resulting in arcing and fire, either immediately or some time after the strike. I've ...
2
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1answer
145 views

How to create measurement points on a PCB for MIPI lane diagnostics?

I am looking for ways to test specifically MIPI DSI lane signal strength (because I am kind of pushing the envelope on the trace length and width), and am happy to add test points to the PCB design. I ...
0
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1answer
105 views

Test patterns for testing high speed trans receivers of fpga [closed]

I know that we can generate all possible patterns using LFSR sequences but this will waste memory as we will have to store pattern to do error checking and storing all from 0 to 2^(n-1) will require ...
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5answers
1k views

How to test the maximum secondary current of a step down transformer?

I got a small step down transformer from my local market which has a total of 6 individually isolated winding in it (1 primary of 230V and 5 different secondary wingding with 5 different voltage). My ...
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6answers
2k views

Techniques for building 'Bed of Nails' testing board

When testing a complete circuit board a 'Bed of Nails' can significantly reduce time and errors. What are some techniques for making a DIY Bed of Nails? ...
2
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2answers
142 views

FPGA Jtag Hooking to User Logic

After some primer reading on jtag it looks to be a nifty means to test a FPGA logic design in a consistent and sustainable way. Let's use altera max 10 as an example. I've read this MAX 10 JTAG ...
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0answers
71 views

Why insulation resistance goes linearly

While we test electrical equipment like transformer the insulation readings goes higher linearly over time,And even to infinity which means the instrument could not measure beyond that, 15Tohm is the ...
0
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2answers
102 views

Ethernet mechanical switch for testing [closed]

We have an application which accepts streams over IP and displays it on the LCD Screen. We want to test the Ethernet plug-in/Plug-out test. Do you know any IC which can simulate someone plugging in ...
0
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0answers
64 views

How to calculate attenuation of two layers of RFI shielding material

I'm developing a type of enclosure that provides EMR shielding. It's constructed of two layers of shielding material. I don't have access to professional test equipment, so my dynamic range is ...
2
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1answer
90 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 ...
1
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1answer
609 views

Calculating AC Input Power

I'm making an AC to DC power supply that connects to mains. There's an AC to DC converter, buck converter and a smoothing LDO that outputs a DC controlled with pots. I'm verifying the supply, and ...
1
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1answer
852 views

Reading values on continuity test but there is no beep

When checking traces of my PCB I realized that checking continuity between one of the output trace and GND some values appear on multimeter screen but the buzzer does not beep. On the Vcc trace ...
9
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4answers
273 views

How are high-speed circuits tested if test equipment doesnt exist?

How was testing done for Ghz to THz range circuits and devices before fast enough scopes and frequency counters existed?
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0answers
26 views

How to diagnose heating issues in charging Lipol cells in series

So please excuse the little doodle was the best way I could think of making myself clear, then blue squares are the lithium ion 4.2 v batteries I have linked in series, now I have a charged that ...
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2answers
283 views

Is it possible to test a MIDI device through its connector with a multimeter?

I have a Fluke 115 multimeter available that I'm hoping has capabilities to register (even with low fidelity) any MIDI signals flowing out of a handful of devices. ...
0
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1answer
187 views

How to safely demonstrate backfeeding AC

I'm looking to setup a basic demo of backfeeding AC and how it effects some AV equipment. My idea was to wire up an extension cord with a three prong if on one end and a simple single gang outlet on ...
2
votes
1answer
131 views

Does DCMI mean dc mA?

I am working with a 60 year old schematic and test procedure. The latter refers to adjusting rheostats to "300 DCMI" or "between 100 and 130 DCMI". There are voltage and ammeters attached to different ...
0
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1answer
101 views

Would it be ok if I try to measure an audio signal using a 15m BNC Cable?

I would need to use a 15 meters BNC Cable (RG58) in order to measure an audio signal that goes directly to a pair of earbuds. This means, the test point would be exactly before the balanced armature ...
0
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2answers
92 views

How much interference is allowed to pass FCC verification testing?

I have a small electronic device that I'm considering bringing to market. It doesn't have any features like wifi or bluetooth, so one of the prerequisite steps before I can sell it is to ensure it ...
1
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1answer
77 views

Testing a diode's electrical characteristics with temperature control

I would like to test a few diodes electrical characteristics at their device low limit, ambient, and device high limit temperatures. I was thinking of using a Peltier element with a heat sink, but I'...