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Beginners / Re: RS232 intermitted issue
« Last post by tzc24 on Today at 11:49:48 pm »I had checked all the tx voltage there are no abnormality found.
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Projects, Designs, and Technical Stuff / Re: Vacuum Fluorescent Display Driver
« Last post by bostonman on Today at 11:49:09 pm »I assume you mean the wires behind the glass?
Nothing seems to glow even faintly. Tomorrow I’ll reflow the pins, but I tend to go heavy with the solder regardless. A quick look earlier didn’t reveal any indication of bad solder or lack of, however, anything is possible.
Odd it was working and nothing more than a power recycle resulted in the display not lighting.
Nothing seems to glow even faintly. Tomorrow I’ll reflow the pins, but I tend to go heavy with the solder regardless. A quick look earlier didn’t reveal any indication of bad solder or lack of, however, anything is possible.
Odd it was working and nothing more than a power recycle resulted in the display not lighting.
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Projects, Designs, and Technical Stuff / SX1280: anyone?
« Last post by SiliconWizard on Today at 11:48:44 pm »Just wondering if anyone here has used the SX1280 in a project, any feedback would be welcome.
https://www.semtech.com/products/wireless-rf/lora-connect/sx1280
https://www.semtech.com/products/wireless-rf/lora-connect/sx1280
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Test Equipment / Re: Heads up on MicSig Probe
« Last post by J-R on Today at 11:46:52 pm »Looks like it is actually a "SainSmart Official" store-wide sale. So be sure to check out their other items if you have money burning a hole in your pocket...
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Projects, Designs, and Technical Stuff / Re: 3D printing company similar to PCBWAY for circuit board
« Last post by ataradov on Today at 11:40:10 pm »Where can you get machined metal for the same price as 3D printed ones? I just tried with a basic half box and 3D printed one was $1.55 at 50 pcs. Machined aluminum one was $17.
You can probably get it cheaper with extruded stuff, but that limits your options quite a bit.
You can probably get it cheaper with extruded stuff, but that limits your options quite a bit.
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Projects, Designs, and Technical Stuff / Re: PC74hct4046ap Replacement
« Last post by PCB.Wiz on Today at 11:38:08 pm »I keep wondering what that 1N4148 is even doing there? It's the oddest circuit I've seen.It looks like a deliberate decision was made to run the PC2 output at not-quite-zero phase.
To balance the 4M7 drain resistor, PC2 will need a steady small pulse offset.
The circuit shows a CLK coming from elsewhere, so that likely dominates here, the PLL may be just for sampling purposes.
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Security / Re: Microsoft repackages apps with a telemetry .NET wrapper
« Last post by SiliconWizard on Today at 11:37:39 pm »I would say that Windows is a great modular spyware system which supports some operating system functions
Yes! This is probably an hyperbole though! MS is only doing this to improve your user experience. Don't you want your experience to be improved?
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Test Equipment / Re: Multimeter selection for production testing
« Last post by J-R on Today at 11:35:43 pm »You didn't mention the voltage range of the device, and I assumed it had some regulation and could handle a 2V drop. Maybe battery powered, such as nominal 4x1.5V or 12V. But if your device runs at 3V I agree 100% with that value being a problem, in which case dropping to 0.1 Ohm might be an option.
100uV is trivial for a 6.5 digit DMM, 10uV is pretty easy with just some sanity checks, and even 1uV is possible if it's decent. The DMM can autorange between 100mV/1V/10V without interrupting the supply.
Thermocouple effects are not much of an issue because you have the same number and type of connections going in as you do out. But ideally still build a shunt configuration that is not going to get warm.
100uV is trivial for a 6.5 digit DMM, 10uV is pretty easy with just some sanity checks, and even 1uV is possible if it's decent. The DMM can autorange between 100mV/1V/10V without interrupting the supply.
Thermocouple effects are not much of an issue because you have the same number and type of connections going in as you do out. But ideally still build a shunt configuration that is not going to get warm.
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Beginners / Re: Checking for noise in resistors
« Last post by floobydust on Today at 11:35:14 pm »From the era of tube gear, many signal tracers have a "NOISE" mode switch built-in. Example Heathkit IT-12.
That applies high voltage bias to the probe about 115VDC/1.7mA and with the audio amplifier you can listen to the result.
A noisy resistor or capacitor with bad dielectric can be flushed out. It was a common problem in the day.
Mr. Carlson's Super Probe has a "noise" switch but I think he's got it wrong and it's the actually RF probe mode.
That applies high voltage bias to the probe about 115VDC/1.7mA and with the audio amplifier you can listen to the result.
A noisy resistor or capacitor with bad dielectric can be flushed out. It was a common problem in the day.
Mr. Carlson's Super Probe has a "noise" switch but I think he's got it wrong and it's the actually RF probe mode.
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Projects, Designs, and Technical Stuff / Re: PC74hct4046ap Replacement
« Last post by PCB.Wiz on Today at 11:31:28 pm »Accordig to this post IR LED is even less noise!In this application, it is not being forward biased continually, so noise is meaningless.
https://www.diyaudio.com/community/threads/some-noise-measurements-for-leds-and-zener-diodes.35821/
Scope the pin, and check the waveform.
It is being used switching, with a narrow duty cycle, so you need low C, low ns and low leakage.
Some Toshiba parts give typicals of 1.6ns, 0.4pF @1V and ~ 1nA at 5V / 25'C