Search found 2970 matches
- Mon Jun 19, 2023 6:01 pm
- Forum: General Discussion
- Topic: Antenna for Cell Phone!
- Replies: 14
- Views: 97342
Re: Antenna for Cell Phone!
I see that link but for the record, those cell phone boosters were for now obsolete Analog phones. Those phones often reduced TX power to save battery, the sticker tricked it into transmitting at full power. besides that, the OP can search cell phone booster and see the same results we did.
- Mon Jan 30, 2023 7:48 pm
- Forum: General Discussion
- Topic: EXTEC meters E320X
- Replies: 16
- Views: 68281
Re: EXTEC meters E320X
well, it's not hard to find a "rechargeable DMM" they charge through a USB port. There must be some obvious safety issue I am missing, certainly it pushes up cost unnecessarily or maybe someone has tied the idea up with a patent. Like this 2012 patent https://patents.google.com/patent/US83...
- Mon Jan 23, 2023 10:50 am
- Forum: General Discussion
- Topic: EXTEC meters E320X
- Replies: 16
- Views: 68281
Re: EXTEC meters E320X
That seems to solve your issue, if you can tolerate one reset. Most meters do this and frankly I like it better than pulling the meter out of the case only to find dead batteries because it was left on. Now if only someone will make a meter with a rechargeable battery that charges through the probes...
- Thu Jan 19, 2023 3:35 pm
- Forum: General Discussion
- Topic: EXTEC meters E320X
- Replies: 16
- Views: 68281
Re: EXTEC meters E320X
Disappointing the links on the manufacturer website to download the manual are totally broken and redirects to FLIR and an error 404 https://www.extech-online.com/index.php?main_page=product_info&cPath=78_16_53&products_id=233&zenid=b9c42bc56e7d790e50f5b56e96dd24ea I did find it here but...
- Tue Jan 17, 2023 11:36 am
- Forum: General Discussion
- Topic: Why you should consider Solar Panel Cooling....
- Replies: 4
- Views: 21932
Re: Why you should consider Solar Panel Cooling....
One's climate would have a lot to say about whether this is practical, but I definitely see an opportunity to piggyback P-V and Hydro-thermal solar systems in one package. Say for an RV or off grid cabin, you can get electricity and warm water in one footprint. Indeed, a search confirms Hybrid PVT p...
- Wed Jan 04, 2023 12:22 pm
- Forum: General Discussion
- Topic: Looking for long range HF RFID antenna
- Replies: 7
- Views: 43078
Re: Looking for long range HF RFID antenna
Just unwrapping the antenna coupling wire from the power cord probably messes with the impedance the antenna input amplifier expects to see. Might need to add an inductor to the wire before interfacing to a whip or rod antenna to match the right impedance. Without a schematic and specs for the RF am...
- Wed Jan 04, 2023 12:17 pm
- Forum: General Discussion
- Topic: Anyone make anything interesting for christmas ?
- Replies: 9
- Views: 28371
Re: Anyone make anything interesting for christmas ?
I'm finally refurbishing my Marantz SR2000 Tuner from 1980. After replacing the fried Rectifiers and testing all the caps, I discovered the main amplifier on the right channel was shorted to the supply with the speaker at 38V (probably why the rectifiers shorted if that happened with an 8 ohm load)....
- Wed Jan 04, 2023 12:06 pm
- Forum: General Discussion
- Topic: Capacitor
- Replies: 7
- Views: 44616
Re: Capacitor
Hard to say exactly what that electrician was trying to achieve but as noted, it wasn't likley for PF correction unless he was misunderstanding how that works, that's mostly valid for inductive loads like motors. Are you sure it wasn't a surge protector instead? Assuming the value of the cap was not...
- Tue Dec 13, 2022 11:21 am
- Forum: General Discussion
- Topic: Looking for long range HF RFID antenna
- Replies: 7
- Views: 43078
Re: Looking for long range HF RFID antenna
Perhaps, but it's not impossible someone might actually join this forum, Is it?
- Mon Dec 12, 2022 4:21 pm
- Forum: General Discussion
- Topic: Looking for long range HF RFID antenna
- Replies: 7
- Views: 43078
Re: Looking for long range HF RFID antenna
Not a simple task given RFID was always intended for short to medium range to provide isolation to other nearby tags. The tag itself determines the range more so than the receiver given how its tiny radio burst signal strength decays at a rate equal to the cube of its distance to the receiver. Shiel...
- Wed Dec 07, 2022 5:59 pm
- Forum: General Discussion
- Topic: HV SMPS design
- Replies: 7
- Views: 25289
Re: HV SMPS design
Thanks, one suggestion of that thread of a relay with 220V coil is workable but I consider unsafe and unreliable for this application, but I did just find this gadget that just might unlock the door to my effort https://www.ebay.com/itm/311864741981?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1kY...
- Wed Dec 07, 2022 10:47 am
- Forum: General Discussion
- Topic: HV SMPS design
- Replies: 7
- Views: 25289
Re: HV SMPS design
you know, I'd be just as happy with a circuit that detects 110V or 220V at the input and toggles a relay or FET switch to direct voltage to the proper primary windings of the transformer. I'm thinking of a way to do that reliably and safely. Thats not SMPS but it satisfies my main goal of eliminatin...
- Tue Dec 06, 2022 3:27 pm
- Forum: General Discussion
- Topic: HV SMPS design
- Replies: 7
- Views: 25289
Re: HV SMPS design
I mean 240V pole to pole with 0V in the middle or -140, 0V, +140V. It's used as a primary unregulated source for a 2 channel +/-100V, 100mA 4 quadrant SMU. I don't expect to find anything off the shelf and want to design one from scratch but can't even find a chipset that could work. I'm not totally...
- Mon Dec 05, 2022 12:20 pm
- Forum: General Discussion
- Topic: HV SMPS design
- Replies: 7
- Views: 25289
HV SMPS design
Has anyone seen a schematic or chipset that can accomplish an SMPS power supply with +/- 140V DC, 250mA? (and Universal AC input). Most designs top out at 36V or perhaps 48V. Were still using a linear supply here and even if I could put an AC universal 110V/220V auto selector in front of it that wou...
- Mon Dec 05, 2022 11:35 am
- Forum: General Discussion
- Topic: Looking for a Blue Led display 4-dig. - 7-segment
- Replies: 17
- Views: 66863
Re: Looking for a Blue Led display 4-dig. - 7-segment
you've been looking for that a long time, nice find. I've been forced into Ali a few times recently for things I used to get elsewhere too.