Recent Posts

91

Other Blogs / Re: KPE - www.kaizerpowerelectronics.dk (see latest post for new videoes)

« Last post by madsbarnkob on Today at 05:38:10 pm »

This is the first video in a series of 3, on how to get started with the UD3 Tesla coil driver. Huge shoutout to Steve Ward, Netzpfuscher (Jens Kerrinnes), Malte0811 and TMaxElectronics (Thorben Zethoff) for their work on the UD3 platform.

92

Beginners / Re: Oscilloscope Noise Issue with Different Resistor Values

« Last post by MarkT on Today at 05:37:36 pm »

Its capacitive coupling to the long leads of the multimeter from the mains wiring in the room and probably from you.

Effectively the noise is constant-current as the source voltage is high and the capacitive reactance large (perhaps a few pF or so).

Given constant current pushing into the resistor, the larger its value, the larger the voltage.

93

Projects, Designs, and Technical Stuff / Re: (Yet Another) DIY Multislope ADC

« Last post by NNNI on Today at 05:36:17 pm »

There's probably a better way to handle that - push rundown to the second PIO instance with a lower clock divider. That way, the PIO instance that handles multislope runup can be run at a reasonable clock speed, and the rundown PIO instance can have higher resolution.

However, that brings me to the question: what's the advantage of rundown vs reading residue using an ADC?

94

Projects, Designs, and Technical Stuff / Re: Identify an old (mid-1970s) 10-bit ADC

« Last post by ballen on Today at 05:36:04 pm »

As I recall it was a module, one of those black potted things with lots of pins, both Burr Brown and Analog Devices made many components in that style in the 1970s and 80s.
Yes, it might have been TRW but I'm 90% sure that it was either Burr Brown or Analog Devices.

I'm trying again for a more reasonably-sized picture and the correct alignment.

[OK, that worked, also fixing it in the original post.]

95

Beginners / Re: New multimeter, is the thermometer good or better standalone?

« Last post by Gyro on Today at 05:34:08 pm »

Welcome.

I find separate is better. This leaves the multimeter free for use at the same time and broadens the choice of available meters. Separate thermocouple thermometers tend to be pretty much as accurate as the multimeter function. The low cost TM-902C has been around for decades now, I don't think they are manually adjustable like the early ones but are probably still good enough. I haven't checked which other ones are available these days.

96

Test Equipment / Re: Tek 2465 Horizontal Sweep Issue

« Last post by Orange on Today at 05:28:09 pm »

There is a good service manual available here https://w140.com/tekwiki/images/8/8b/070-3831-00.pdf
It has a flow chart for diagnosing the sweep circuit on page 283

97

Test Equipment / Re: Looking for a replacement general purpose oscilloscope for home use

« Last post by Kosmic on Today at 05:24:47 pm »

I unfortunately don't have the change log.

98

Test Equipment / Re: Looking for a replacement general purpose oscilloscope for home use

« Last post by joeqsmith on Today at 05:21:46 pm »

On the 7300a you can slow down calibration and disable temperature related calibration. I guess this is not available on all models.

Similar to the WaveBluder.  I leave it on as it does me no good.   Autocal on this scope takes maybe 1 - 3 seconds.  Basically a life time.

I have been using firmware 7.6.1.1.   Guessing this was from 2014, as it appears I archived it.  So if you decide to check the change log, it at least gives you a starting point. 

99

Beginners / Re: Dimming signal 0-12V from microcontroller (logic level to 12V PWM)

« Last post by Zero999 on Today at 05:21:44 pm »

The MCP1402 appears to be fine for just level shifting the 3.3V to 12V. It's possibly a bit overkill. A single BJT will probably do.


^{Level shift bi-direc BJT 3.3V 5V.asc}

100

Test Equipment / Re: DER-EE DE-5000 ESR zero measurement problem.

« Last post by TA3UIS on Today at 05:21:13 pm »

I connected 3 pieces of 1ohm parallel resistor in series to a 10,000uf capacitor. ESR measurement was successful.
What would this measurement reveal?

Is DE-5000 good or defective?