Ask an Expert Forum - Recent Threads

Difficulty soldering to pin headers

5ilicon — Thu, 05 Nov 2026 10:45:56 GMT

I have been struggling to solder tinned stranded wire to gold-plated pin headers. The solder doesn't seem to adhere to the pins.

I have tried lightly abrading the pin surface and cleaning with Isopropanol, applying liquid flux, increasing the iron tip temperature to 400°C!

Eventually, the wire attaches using the high temperature however, sometimes not very well. The pins also melt the plastic support material and come loose.

These are the pin headers:

Any suggestions?

Do we have Dongle schematics in open net by any chance? would wish to understand this module.

Humaninsane — Tue, 27 Oct 2026 06:42:50 GMT

So as the title suggest i need to understand the Dongle schematic. I have a thought to integrate it to keypad phone, use it as Dumb phone with Hotspot when required.

Mobile phone

Dalle776677 — Fri, 23 Oct 2026 12:49:00 GMT

Im Lukas

I have an idea an new smartphone

How can I make an prototype for free.

How to determine the health state of a LiPo battery?

obones — Fri, 02 Oct 2026 06:45:44 GMT

Hello,

I have taken out those two batteries from a device that needs both.
Clearly, the one on the right is dead and needs replacing.

However, I'm wondering about the state of the one on the left as it was manufactured at the same time.

Considering how expensive it is to come by the same model in France, I'd rather avoid buying two when one would be enough.

Here, I have a bench power supply, a bench DMM, an oscilloscope, a few ESP32s or arduino, even a RedPitaya but I doubt this one would be of any help here without specialized apparatus.

Many thanks for any suggestion.

ARC760-B pin information

SamW1993 — Fri, 02 Oct 2026 01:36:27 GMT

Hello everyone,

I want to get the pin information of ARC760-B chip SCSI bridge.

I would be grateful for even the slightest bit of help.

Thank you.

I need a datasheet or reference of this chip

SamW1993 — Thu, 01 Oct 2026 23:20:02 GMT

Hello everyone,

I am analyzing the old PCB, E4440 board.

So I need a datasheet or reference doc for ARC760-B chip.

Thanks.

Experience using Lascar EasyLog Data Logger

kinoni — Mon, 28 Sep 2026 16:01:15 GMT

Hello, has anyone used the Lascar EasyLog Data Logger before? Is it normal for the logger to functioning inconsistently during first few datalogging sessions? (i.e. due to slight movement disconnecting the internal circuit connection, disabling the datalogging function midway datalogging session)

Design a Non-Contact RPM meter

Humaninsane — Thu, 24 Sep 2026 06:55:04 GMT

I am currently reverse-engineering a non-contact RPM sensor module that uses a Bosch knock sensor (

Knock Sensors (0261231046) - Knock Sensors - Bosch Auto Parts)

and a Condenser MIC output as the input. The knock sensor and MIC signal is fed into 2 separate op-amp

LMC66x CMOS Dual Operational Amplifiers datasheet (Rev. D)

, and the op-amp output goes to a CODEC

AD1845 , DigChip http://www.digchip.com

for processing.

My goal is to understand the op-amp circuitry and determine the appropriate configuration needed to condition the knock sensor and MIC signal before feeding it to the CODEC. I am a bit confused about where to start and what concepts I should study regarding op-amp. and there is a charge pump as well,

LT1054 Switched-Capacitor Voltage Converters With Regulators datasheet (Rev. G)

Could anyone guide me on:

How to analyze the existing op-amp circuit?
What op-amp configurations are commonly used for piezoelectric sensors such as knock sensors?
What topics should I study to better understand this signal-conditioning stage?
How can I determine the expected signal levels and bandwidth requirements before the CODEC input?

The ultimate task is to redesign this board while maintaining identical functionality and output behavior as the existing device, so understanding the analog front-end is critical.

Any suggestions on the right approach, reference materials, or debugging techniques would be greatly appreciated.

AI is confusing with too much data. Not getting a clear path.

Identification of a Littelfuse Component

suhas.s.lohiagroup — Tue, 22 Sep 2026 08:41:17 GMT

Please help me get me the MPN of the part in the attached image

CMX60D10

qwertyman — Tue, 01 Sep 2026 08:34:21 GMT

Hi, good day.

May we confirm if the front markings on the two CMX60D10 components being different in size are considered normal?

we have found these two part in one box.

Could you please confirm if this is an acceptable manufacturing variation or a factory defect?

Thank you.

Allen-Bradley PLC Systems

navahmed — Sun, 30 Aug 2026 13:03:24 GMT

Looking for tips on Allen-Bradley PLC systems.
Discussing ControlLogix and CompactLogix applications.
PLC programming, I/O, and EtherNet/IP networking.
HMI and SCADA integration with Allen-Bradley PLCs.
Troubleshooting, setup, and automation best practices.

Question: Industrial optocouplers keep failing on-site, what thermal management products can solve this issue?

wanjieyu_. — Thu, 06 Aug 2026 03:36:45 GMT

The optocouplers on our production line control boards work under continuous high-temperature conditions and often suffer breakdowns or signal distortion failures.

Besides standard cooling fans, I’m wondering what mature thermal management products, thermal conductive components or circuit design solutions are available to reduce high-temperature damage.

It would be much appreciated if anyone could share solutions that have been applied in industrial or automotive projects.

MMM (Multifrequency, Modulated, and Multi-wave) Ultrasonic Technology

Rick1234 — Mon, 03 Aug 2026 03:32:16 GMT

Hello Element14 community!

My quest is to build an MMM ultrasonic water treatment system for use in the motel and laundromat industries.

Basically, to ultrasonically negate the scaling ability of the minerals in the water before they can form on the inside of the pipes and heat exchangers walls.

The MMM paradigm greatly eases the normally strict mechanical ultrasonic interface to the target load ..... as the MMM generator constantly frequency "sweeps" and "optimizes" its effects on the scaling minerals in the water.

My early thoughts:

PC control to set parameters (power, frequency sweep, modulation, etc) + Adaptive Digital Signal Processor (ADSP) + Ultrasonic Power Driver

Minimum ultrasonic "contact" time with the scaling minerals (calcium & magnesium) during a max. 50 gpm water flow rate = 1.5 seconds

Ultrasonic transducer and horn to be of a "clamp-on" type design (ie: surrounding the water feed pipe)

The main attribute of MMM is its ability to "self-adapt" to any varying physical sonic envelope and load ..... on-the fly! (w/feedback loop sensor)

Its my contention, that in this application, the sonic envelope (pipe) and load (water) is "fixed" and should afford a simpler software implementation script.

Where to start? (Note: i'm day one working with ultrasonics!)

Can anyone recommend a preassembled factory evaluation ADSP board suitable for this application and an ultrasonic power driver board?

Thank-you!

Soldering iron station that suddenly does not heat anymore

obones — Mon, 20 Jul 2026 14:45:22 GMT

Hello,

I have a soldering "station" that has been working just fine for quite a while now and up until this morning. You can get a glimpse of it in this message: Finally took the time to reorganize the workbench!

But this afternoon, when I turn it on, the usual two left LEDs turn on, one for "there is power" and one for "heating up" but the iron tip and body do not get hot at all and the temperature bar does not light up to the set temperature.

What could be the reason? What should I look at in the hopes of repairing it?

a small request

ezain — Mon, 13 Jul 2026 13:35:13 GMT

dear engineers
I only wanted to ask for some courses that explain ICs from start to end ( explained easy and full all versions) like op amps and more cause jumping from transistors to them makes it hard to grasp is you have a very good one please tell
( I kept this short cause I am in hurry)
also tell if i have to remember all of them and their working.
thanks in advance

How to use a Monitor with Display Port on Raspberry Pi 5

perryaire — Mon, 13 Jul 2026 02:59:50 GMT

For about 20 years I used a KVM switch that switched monitors that had DVI connectors, I as able to connect my RaspberryPi 5 through this switch using a cable that had micro HDMI on one end a DVI on the other. The DVI KVM Switch failed and is not replaceable. I have replaced it with a KVM switch that switches monitors with Display Port. I managed to connect my Windows and Mac computers using this switch (requires complete recabling) but I am having trouble with the Raspberry Pi. I have a micro Hdmi to hdmi adapter to which I connect an Hdmi to Display port cable. These two cables together are connected to the KVM pitch input. Kvm Switch output is connected to monitors (display port to display port). The Pi boots but the desktop does not display on the monitor.

I know the Pi is still working. I tested using a TV that has Hdmi inputs and the Pi ends up wonting through the switch for Keyboard and Mouse and the TV for monitor. The Pi does not display on the switched monitor. I would like to be able to use the pi through the switch. Anybody have any thoughts on what is preventing the signal from reaching the monitor?

Thanks in advance for any suggestions.

Perry Sugerman

Downers Grove, IL

Can anyone assist with diagram of connections for anchor rod control system based on Hall effect?

Irek — Mon, 22 Jun 2026 17:32:40 GMT

It should count numer of revolutions (not rpm) of the gybsy wheel of the anchor winch./ik

Diagram that I have drawn can be sent to interested party./ik

Use of Hall effect sensor for revolutions counter (not tacho)

Irek — Mon, 22 Jun 2026 16:46:23 GMT

I have designed a schematics for use of Hall effect sensor to count revolutions of the gypsy wheel on my (small) anchor winch. I am using commercially available Hall sensor and display (fm China as could not find any shop in Canada offering these eements). Unfortunately I was unable to attach the scan of the diagram. Will share via email with anyone who is willing to assist.

I tried it on the bench and it work well. Once installed and reseted it stopped working. Can anyone look at my diagram and proof read it? I would appreciate contact via email to provide further docs if needed.

community.element14.com/.../1803.Rod-counter-schematic.pdf

Looking for an oscilloscope / logic analyser, maybe usb?

stanto — Sun, 21 Jun 2026 12:44:19 GMT

Anyone using a portable/handheld oscilloscope/logic analyzer?

Im looking for recommendations of something to pick up.

Ideally with capabilities to hook into python or coding libraries over USB too.

Output current, LED Color, Wattage LED Driver

rgovande26 — Tue, 16 Jun 2026 15:52:52 GMT

I am new to this group.

LED driver is new for me and I am learning about it now!

I recently started working on 8' LED tube light. It uses HOSSONI LED Driver (Ballast) SDC96CS200V48DL1A. I believe this is a Constant Current Driver.

t has following:

Input voltage measured is 120Vac
Output: 36-48Vdc, Actual No-load voltage: 55Vdc
3-wires are connected to the LED lights
3 position switch to select the color 5000-4000-3500K
Aux Output: 0-10Vdc (Not used)
0-10Vdc for Dimmer So, a non-dimmable LED Driver should work.

Questions:

A 3 position switch is used to set the color. Does this switch actually changes output currents to 1150mA, 1500mA, or 2000mA?
Does Higher the output current mean higher K value?
There is another switch for Wattage setting; 90-68-48W. What's the meaning of this? Is this the power wattage available or applied to the LED light?
Does the change in output current changes above wattage (90-68-48W)?

Please let me know if more information is required from my side.

Thanks

Bosch Plena LBB1935 schematic

jsmartins — Tue, 02 Jun 2026 23:11:46 GMT

Hello,

I have two Bosch Plena LBB1935 amplifiers that need repair. On the main bord there are some resistores with burn signs but i will nee the schematic to find the right values. Anyone have the circuit that can share a copy?

Thanks

José Martins

Do I need to add more components to make this transformer safer?

HKPhysicist — Mon, 01 Jun 2026 16:14:36 GMT

Dear all Electrical and Electronic Engineers,

I own an audiophile grade Sony blue disc player. It accept 115V AC.

Then, I bought this transformer which transforms my wall outlet 230V AC to 115V AC, which is then connected to my Sony Disc Player.

https://hk.element14.com/triad-magnetics/vpt230-110/transformer-toroidal-2-x-115v/dp/1785731

Do you think whether I need to add additional components to make this transformer safer to work? I have already bought another beautiful aluminium enclosure to contain it. 😀

The main point is - it is an audiophile grade system. Additional components may degrade the final sound quality.

So, there is a dilemma.

Clarification on AD7192 System Calibration Input Span vs Observed Full-Scale Behavior

Jay_Instrument — Sat, 30 May 2026 06:48:15 GMT

Hello,

We are currently evaluating the AD7192 ADC as a replacement for the obsolete CS5532 in our load cell application.

With the CS5532, after system calibration, we were able to achieve full-scale output at an input of 10 mV. While testing the AD7192, we are observing behavior that does not fully align with the system calibration input span specifications given in the datasheet.

Our configuration is as follows:

Reference voltage (Vref): 5 V
Gain: 128
Calculated full-scale input range (FS): 39 mV

As per the datasheet, the allowable input span for system calibration is:

Minimum input: 0.8 × FS ≈ 31 mV
Maximum input: 2.1 × FS ≈ 81 mV

However, our load cell has a maximum output of 10 mV, which is significantly below the specified minimum calibration span.

Observed behavior:

We tested inputs at 10 mV, 15 mV, and 30 mV.
We begin to observe full-scale counts starting at approximately 15 mV.
This is notably lower than the expected ~31 mV minimum based on the datasheet.

Questions:

What could explain achieving full-scale counts at ~15 mV, which is below the specified minimum system calibration span?
Is this behavior valid and reliable for production use, or could it lead to accuracy or stability issues?
Given our load cell output (max 10 mV), would you recommend proceeding with AD7192, or should we consider alternative configurations or devices?

Additionally, could you please connect us with an Analog Devices application engineer to further investigate and discuss this issue in detail?

We would appreciate your guidance in understanding whether this observed behavior is within acceptable operation limits and suitable for long-term use.

Has anyone worked on Integrating with openplotter for AIS ADSB marine Ham band monitoring?

KariR — Wed, 20 May 2026 12:33:57 GMT

I'm interested in replacing my sdr dongles with this kit to integrate AIS ADSB Marine and Ham band monitoring. The capabilities of the kit fit nicely and will allow for simultaneous wideband monitoring over a very wide spectrum

Would someone be interested to create Ben Bulsink's NFC Game Board?

Luka851 — Mon, 18 May 2026 13:10:51 GMT

Hello everyone,

I wanted to make a custom smart chess board and I came across to Ben Bulsink's open source technology on nfcgameboard.com. Following is a demo video of his creation: https://www.youtube.com/watch?v=4qKndjF60Js&t=12s.

I wrote to him, and together we decided to upgrade the device and use the newer PN5180 IC instead of the CLRC632 IC that he used in the prototype. We used Playfultechnology library for PN5180 and encountered issues, such as the library wasn't detecting multiple tags. We have solved and improved that library, and that challenge now is solved, however we now encountered next issue which is connecting the IC to the external antenna. When we cut the PCB antenna traces on the module the IC stops to respond correctly, such as returning EEPROM and seems to get stuck in the loop even before it reaches communicating with the antenna. We don't know what may be causing this. Does anyone has any idea on it and how to fix this?

My next question is will there be anyone who would be curious enough to also try to recreate the improved board? We want to create an open source technology - hardware as a sandbox, so anyone can make the board, and then write their own code to create any kind of the game on top on it, whatever they want, perhaps share their game on the common platform with other players to download and play their games. We are communicating through email and having more brains working on it will make things easier, faster, and thought maybe ask if anyone was interested to join, will be here to help and explain, what I know.

https://nfcgameboard.com/schematics/ - gives the idea, schematics, pcb, and similar, but for CLRC632. in short, we will make 15x15 grid board, using multiplex antennas - each antenna being 15x30mm, we will have then 30 antennas (15 rows, and 15 columns), instead of 225 small antennas, a matching circuit and one PN5180 IC.