Recent Posts

1

Beginners / Re: Oscilloscope recommendation

« Last post by tatel on Today at 02:31:21 am »

Are there special protocol decoding features that are needed or anything like that?

Yep. I would like to see some comments about CAN decoding and one of two channels. It looks that CAN signal is a differential one? I guess one just need to look if the signal is OK, and that it would be easier and cleaner to use OBD to see the decoded messages.

I also guess that, while inconvenient, a one-channel device would be enough to look at both halves of the signal, even it only one at the time. After the videos, it looks quite easy to see if there's a 5V signal or is instead showing "flats"

2

Repair / Re: Please help, how can I adjust this transistor?

« Last post by daisizhou on Today at 02:22:53 am »

OK. this is a test video,The TP3 waveform looks a little different than before.
Looking forward to your analysis or further testing.

3

General Technical Chat / Re: What ICs are used in this rocket?

« Last post by Andy Chee on Today at 02:15:38 am »

Or do all the Chinese's internal PSU's (for sale only inside China) use software controlled Power supply control chips?

I've been to the electronics markets in China.

It's safe to say that, counterfeits notwithstanding, Chinese government has ready access to the same commercial component inventory as Western electronics manufacturers.

In other words, there are no export restrictions on China.  Iran and North Korea are very different export situations.  Iran and NK will rely heavily on third parties to ship restricted electronics.

4

Beginners / Building a DIY PAPR but the fan has odor

« Last post by engineheat on Today at 02:13:48 am »

Hi,
I tried building a DIY powered respirator using a 12V DC blower like shown below:


I used an Arduino to control the fan speed via PWM, and I build a housing for the fan and filter. It works and the air flow is sufficient. My only problem is that the fan has an chemical/plasticky odor. This causes the air to also smell. I don't think it's due to overheating because even a newly arrived fan has an odor from the outlet, even when powered off. So I'm wondering if this is normal for fans like that? The smell seems to be coming from the stator/winding because I broke apart a non-used fan.

Perhaps the fans I got isn't really suitable for this purpose. Can anyone recommend a more suitable fan for this usage? I wonder what type of fans are used in commercial PAPRs.

Please advise.
Thanks

5

Projects, Designs, and Technical Stuff / Re: Unable to communicate with I2C fuel gauge

« Last post by davegravy on Today at 02:07:29 am »

I picked up a LA this afternoon and here is the result from i2cdump



That appears to be the correct address pattern (1100011) from the datasheet, but no ACK received. SCL frequency is 100kHz.

Is this a problem of logic level? The SBC is outputting 1.8V logic, the datasheet shows Logic Input Threshold (V_ITH) as between 0.5 and 1.4V.

I'm a bit stumped.

6

FPGA / Re: Lattice has silently removed free iCEcube2 license and now charging $471

« Last post by trossin on Today at 02:06:31 am »

I emailed them yesterday to complain and got an email back with the same info. I guess the pressure we all applied worked out.

7

Repair / Re: Blaupunkt CR-4096 AM/FM/Cassette playing speed too fast

« Last post by jcoda95 on Today at 01:50:53 am »

Appreciate the info. This gives me some add’l direction on what to check out.

Thank you,
Jeff

8

Other Equipment & Products / Re: What ever happened to Amazing1.com (aka Information Unlimited)?

« Last post by mindcrime on Today at 01:44:52 am »

So if ANYBODY here actually knows what this guy's family did with his stash of 30kv ac-output flybacks after he died and they shut down his website, I would REALLY REALLY REALLY REALLY like to know. I was going to buy one, but sadly his website was taken offline before I could buy one. So any alternative means to purchase one of these would be great. This request goes out to all members of this forum. If you have the phone numbers or email addresses of any of this guy's surviving family members, who might be willing to sell this his equipment, please let me know. I'm really desperate to buy one of these.

I don't have any first-hand info, but FWIW some basic OSINT stuff would probably turn up a way to get in touch with his family. Note however that I have NO idea how receptive they would be to being contacted about anything like this.

Anyway, his obituary is here:

https://www.smith-heald.com/obituaries/Robert-E-Iannini?obId=27660790

And that lists the names of his immediate family. His Facebook profile appears to still be active and may be monitored by family members? And the FB profile shows a "friend" link to somebody with the same name as his wife, so that's probably her. If anyone is really interested, I imagine you could do a little more poking and find a way to contact somebody.

9

Test Equipment / Re: Siglent SDS800X HD Review & Demonstration Thread

« Last post by joeqsmith on Today at 01:36:59 am »

Watched Dave's recent Rigol DHO800 review, the connector SNAFU and the oops retraction.  Part of this video he is comparing with a low end Siglent off and on.  Puts it in a bad light but I assume that was because he was beating the price drum.   

10

Repair / Re: Can anyone help identify this ON semi IC?

« Last post by srb1954 on Today at 01:36:19 am »

I'll check out the datasheet on it and see what the pinout is on it. 

Thanks, I'll check it out.

Why no datasheet?  Could it be proprietary just for the products company?

Ken

Add the On Semi prefix "MC" on the beginning of the part number and you will easily find a datasheet.