- USB charger from car battery inside house when power goes out - 5 Updates
- Tone controls and 'anti-log' potentiometers - 8 Updates
- Tek 465 degree-of-difficulty repair - 1 Update
| Jeff Liebermann <jeffl@cruzio.com>: Oct 03 11:12AM -0700 >My apologies. Here is a photo of the insides and the model number plate. >https://i.postimg.cc/pVgpNhY1/inside.jpg >https://i.postimg.cc/9f8QLrQb/outside.jpg I have an old DVR (buried somewhere) that looks similar to the one in your photo. I can't see a tiny fan in your photo, but if it's like mine, the fan burns out every year and has to be replaced. Fortunately, I have a large number of fans. The power supply connector inside is a SATA power connector that's intended to only power a single SATA hard disk drive. In other words, I have no idea how much power can be provided by the 5V line or USB port. I assume the USB port will do at least 0.5A charge current, which will work with most phones, but will be depressingly slow. The label is marked "Output 12V 2A". I can't tell what they mean by that. Is that actually the input from the external AC power supply "brick" that you haven't mentioned? Or is it the power supply voltage needed to power the various external cameras? My guess it's the "brick" output voltage and current, but I'm not sure. Rather than try to figure it out, I again suggest that you give up on the idea of using the DVR or its power supply, and connect a USB cigarette lighter adapter to your 12V battery. That's roughly how I made it through the latest PG&E power outages. Want me to post a photo of my messy setup? -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558 |
| Ralph Phillips <ralphp@philent.biz>: Oct 03 09:50PM -0500 On 10/2/2021 8:03 PM, RonTheGuy wrote: > The only question, really, is whether the car battery itself can power the > Lorex DVR Model #LH030800 sufficient for the two USB-A ports to work. > Ron, the humblest guy in town. That sounds like Rube Goldberging it. I'd suggest, instead, something like https://smile.amazon.com/StickyDeal-2-Pack-Converter-Adapter-Step-Down/dp/B09B2Y71F7/ . I have several that are shaped into a accessory-jack sized housing wired into my dash; and a couple of flat buck converter boards around for extra USB ports in my truck. Same thing will work for your charging at the house. THESE are encapsulated to keep any short damage out. And avoids the load of that DVR on the battery while charging the phone. RwP |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 03 08:50PM -0700 On Sun, 3 Oct 2021 21:50:05 -0500, Ralph Phillips <ralphp@philent.biz> wrote: >THESE are encapsulated to keep any short damage out. >And avoids the load of that DVR on the battery while charging the phone. >RwP I agree. Much better. I just ordered two of them on eBay: <https://www.ebay.com/itm/321645899181> Time to get rid of the cigarette igniter to USB adapter, hose clamp, and clip lead abomination. I was going to build my own from one of the buck inverter boards found on eBay, but this looks better. Thanks. Also, I forgot to mumble that I have several large "USB power bank" devices made to power smartphones. Something like these: <https://www.ebay.com/sch/i.html?_nkw=usb+battery+power+bank> <https://www.google.com/search?q=usb+power+bank&tbm=isch> I bought most of mine at a garage sale, where the former owner somehow killed most of the 18650 LiIon cells. They were moderately easy to replace with a (borrowed) spot welder and some nickel flat wire. While USB power banks do not have the capacity of a lead-acid car battery, they also don't have the potential to make a giant mess. I've charged various lead acid and AGM batteries on my Formica workbench, Formica computer desk, and oak kitchen table. I ruined them all with acid burns. I've never had a hydrogen explosion indoors, but have seen two in various automobiles (not mine). I now do all my storage battery charging outdoors: <http://www.learnbydestroying.com/jeffl/crud/DuroMax%20XP4400E.jpg> <http://www.dekabatteries.com/assets/base/0008DekaLG.pdf> Note the lack of battery fill plugs and vents. If a spark gets into that battery, it's likely to blow the top or a side off the battery. Best to be very careful, very safe, and charge hydrogen gas belching batteries outdoors. -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558 |
| Rich <rich@example.invalid>: Oct 04 02:36PM > Time to get rid of the cigarette igniter to USB adapter, hose clamp, > and clip lead abomination. I was going to build my own from one of > the buck inverter boards found on eBay, but this looks better. Thanks. One of "Amazon's" suggestions to Ralph's suggestion was this: https://smile.amazon.com/StickyDeal-2-Pack-Converter-Adapter-Step-Down/dp/B09B2Y71F7/ which matches the OP's original use perfectly. Battery clips for attaching to the battery and four usb charge output ports for charging "phones". |
| "Peter W." <peterwieck33@gmail.com>: Oct 04 09:15AM -0700 We need to understand the purpose of this group - which is to give the most complicated and unsuitable possible solution to the simplest request entirely without reference to common sense, life-safety or cost. Peter Wieck Melrose Park, PA |
| Chris M. White <cw9877@gsm.com>: Oct 03 05:43PM +0100 Hey gang, Does anyone know if anti-log pots are more prone to failure? I bought an old vintage broadcast radio that has separate bass and treble controls and for some reason they've used an anti-log pot for the treble - and it doesn't do nothing. Apart from that, the radio seems fine so I'd like to get it fixed. I've never encountered 'anti-log' pots before (never even heard of them) and am just curious as to if they're more likely to fail. Thanks all, Chris. PS: the radio in question is a Hacker Sovereign II from about 1970 made in liddle ol' England. |
| "Peter W." <peterwieck33@gmail.com>: Oct 03 10:01AM -0700 No more so than any other pot - just a tad more difficult to make. Point of the choice, initially, was to make the pot travel more linear to the human ear, vs. electrically. They are easily obtained in most common values, other than the fact that the Brits, like the French, when they made their electronics copied no one, and no one copied them. I would first try cleaning the pot. I do not know how the treble-circuit is designed in that radio - other than the pot-resistor wants to be in-circuit in many designs, so it could be as simple as something in the wiper. Further, if the overall pot value and current-handling capacity is correct, the only difference between OEM and a replacement - anti-log or not - would be the response-to-travel perception. Peter Wieck Melrose Park, PA |
| Ralph Mowery <rmowery42@charter.net>: Oct 03 01:11PM -0400 In article <i4njlght4300h0hb0c6t9iceun3oe3b6q1@4ax.com>, cw9877@gsm.com says... > fine so I'd like to get it fixed. I've never encountered 'anti-log' > pots before (never even heard of them) and am just curious as to if > they're more likely to fail. Pots like anti-log, log, linear are just ways of how the resistance changes as the knob is turned. Many audio type pots will be log or anti-log so that as they are turned the results seem linear to the ear as the ear is not a linear device,but more of a log type of device. A linear taper pot will be turned just a little on one end of the rotation and a lot on the other end of the rotation to get the same effect. The resistance of a linear pot will change the same ammount no matter where on the rotation it is. A log and anti-log pot will change resistance very much on one end and not much on the other end of the rotation for the same ammount of degreese the shaft is rotated. So the taper should not make any difference in the life of a pot. |
| Chris M. White <cw9877@gsm.com>: Oct 03 06:15PM +0100 On Sun, 3 Oct 2021 10:01:40 -0700 (PDT), "Peter W." >I would first try cleaning the pot. I do not know how the treble-circuit is designed in that radio - other than the pot-resistor wants to be in-circuit in many designs, so it could be as simple as something in the wiper. Further, if the overall pot value and current-handling capacity is correct, the only difference between OEM and a replacement - anti-log or not - would be the response-to-travel perception. >Peter Wieck >Melrose Park, PA Thanks. I came across the relevant schematic fragment online showing the tone controls for bass and treble. I can't see how they work unless they form some sort of elementary network with the 2.5uF C11. Hard to say with those pesky sockets in the way of the signal path. It's about a third of the way down the page in this document: https://www.microscopy-uk.org.uk/mag/artjan13/iw-radio2.html |
| Ralph Mowery <rmowery42@charter.net>: Oct 03 02:17PM -0400 In article <cvojlgdenm5kj60jajnsubdkj5937f8vrm@4ax.com>, cw9877@gsm.com says... > https://www.microscopy-uk.org.uk/mag/artjan13/iw-radio2.html From the looks of things there is no way to tell how the base and tresle controls work. They are shown to go into the block diagram to the right of the 2 batteries. There could be anything in that block.It is doubtful that the C11 has anything to do with the 2 pots. |
| Phil Allison <pallison49@gmail.com>: Oct 03 01:57PM -0700 Chris M. White wrote: ================= > Does anyone know if anti-log pots are more prone to failure? ** I do. > an old vintage broadcast radio that has separate bass and treble > controls and for some reason they've used an anti-log pot for the > treble - and it doesn't do nothing. ** So you can't say if it is a cut or boost ? > fine so I'd like to get it fixed. I've never encountered 'anti-log' > pots before (never even heard of them) and am just curious as to if > they're more likely to fail. ** Rare to see one in a tone circuit. But very common the the "gain" control of mic pre-amps. Here the gain increases as the resistance reduces, so a normal log pot has to operate anticlockwise. BTW when you have a sample size of one, probability theory does not work. ...... Phil |
| Phil Allison <pallison49@gmail.com>: Oct 03 02:00PM -0700 Ralph Mowery wrote: ======================= > So the taper should not make any difference in the life of a pot. ** Don't be so sure. Most reverse log pots are made by installing the carbon element from a log pot upside down. That has an effect on reliability. ...... Phil |
| Chris M. White <cw9877@gsm.com>: Oct 03 10:02PM +0100 On Sun, 3 Oct 2021 14:17:21 -0400, Ralph Mowery >controls work. They are shown to go into the block diagram to the right >of the 2 batteries. There could be anything in that block.It is >doubtful that the C11 has anything to do with the 2 pots. Thanks for your observations. That explains a lot. I'll need to order a service manual for this radio off the Web as there's no free downloads for this model available anywhere. Until that arrives, there's nothing more I can do. |
| Paul S. Barford <paulb@notformail.com>: Oct 03 06:07PM +0100 On Mon, 30 Aug 2021 14:45:23 -0700 (PDT), Phil Allison >> scope. >** You are asking a " Schrodinger's Cat " type question. >The cat can be thought dead or alive - until you open the box. That has to be the *dumbest* exposition of the Copenhagen Interpretation I've ever seen. I'd stick to soldering bits of wire together IIWY. -- Dr. Paul S. Barford, Rochester New York, USA psb6@harvard.edu PSB Consulting, NYC, NY and Cambridge MA |
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