Why are they unhappy? Because it keeps breaking? Or because it uses 5G?
From: AF <[email protected]> On Behalf Of Adam Moffett Sent: Thursday, June 5, 2025 5:42 PM To: AnimalFarm Microwave Users Group <[email protected]> Subject: Re: [AFMUG] SSR control circuit over voltage The router is Peplink BR Mini 5G. I have no idea what carrier. The cops aren’t happy with it though. Get Outlook for iOS <https://aka.ms/o0ukef> _____ From: AF <[email protected] <mailto:[email protected]> > on behalf of Steve Jones <[email protected] <mailto:[email protected]> > Sent: Thursday, June 5, 2025 3:57:31 PM To: AnimalFarm Microwave Users Group <[email protected] <mailto:[email protected]> > Subject: Re: [AFMUG] SSR control circuit over voltage Im curious about the cellular solution I have municipal traffic cams that I can see finding a cellular solution for that wouldnt generate high usage bills or deprioritization for 24x7 streams On Thu, Jun 5, 2025 at 12:54 PM Adam Moffett <[email protected] <mailto:[email protected]> > wrote: You guys would know better than me on the specifics. I’m assessing bringing fiber to a bunch of police camera sites which are currently on cellular. I was looking through their enclosure to assess putting an ONT in it. They have a Meanwell 48V PSU connected to a terminal bus. The terminal bus feeds an industrial POE (802.3af) switch, and also the NO relay which passes power to a single port POE+ injector (802.3at) which powers the cellular router (Peplink). Finally they have a poe port from the switch going to a poe extractor/splitter, and the dc output from that goes to the control terminals on the relay. So a poe port on the switch is dedicated to keeping the relay closed so that the POE+ adapter stays on. And I assume they did that so they could use the auto-ping reboot. I met the customer today and said I thought there was a design issue in the camera box which would be effectively a time bomb causing sites to go down. I asked how long it had been running and if they’d had any problems, and that’s when I learned it only been two months and two sites have already gone offline. Now here’s another possible dumbness: the router says 802.3at on the spec sheet, but it only needs 11-13 Watts. I think it would have worked on the regular 802.3af poe ports without all the extra pieces. I thought they were backwards compatible as long as you didn’t need the extra power. Get Outlook for iOS <https://aka.ms/o0ukef> _____ From: AF <[email protected] <mailto:[email protected]> > on behalf of Ken Hohhof <[email protected] <mailto:[email protected]> > Sent: Thursday, June 5, 2025 11:54:25 AM To: 'AnimalFarm Microwave Users Group' <[email protected] <mailto:[email protected]> > Subject: Re: [AFMUG] SSR control circuit over voltage Oh, good point, optical isolation. I guess double the LED current could burn it out over time. From: AF <[email protected] <mailto:[email protected]> > On Behalf Of Bill Prince Sent: Thursday, June 5, 2025 10:46 AM To: [email protected] <mailto:[email protected]> Subject: Re: [AFMUG] SSR control circuit over voltage This going back into my fuzzy memory, but I was on a project where we used a bunch of SSRs back in ~~ 1990 or thereabouts. My recollection is that they used an LED internally. That may have just been the brand we were using at the time. bp <part15sbs{at}gmail{dot}com> On 6/5/2025 7:52 AM, Ken Hohhof wrote: So if it’s a solid state relay, there’s probably a silicon controlled rectifier or triac and no actual relay coil? The control voltage probably goes through a resistor to the gate of an SCR. I’m no expert, but I’m guessing they’re fine, especially if it’s been working all this time. They may even have checked with the component manufacturer and verified it will work with the higher voltage. The 30VDC spec might just be a UL thing. Perhaps it’s like 1N400x series rectifier diodes. Do we really think they manufacture or test them differently to get 50, 100, 200, 400 volt ratings? They’re probably all the same diodes just with different markings. If I were designing something for mass production, I wouldn’t do it. I’ve certainly seen problems caused by designs that worked but the components specs were inadequate. Like a manufacturer does a die shrink on a logic chip and it gets faster and now there’s a race condition. Or a different manufacturer with an equivalent part gets substituted and now 48VDC is too much. From: AF <mailto:[email protected]> <[email protected]> On Behalf Of Adam Moffett Sent: Thursday, June 5, 2025 7:59 AM To: 'AnimalFarm Microwave Users Group' <mailto:[email protected]> <[email protected]> Subject: [AFMUG] SSR control circuit over voltage I was looking at pictures of someone else’s enclosure (a camera company). They have a router powered through a NO solid state relay and they’re keeping the coil circuit energized continuously. The specs on the relay say the control voltage is 10-30VDC, but these folks have a 48V power supply. I’m not sure how long it’s been in service (finding out today), but I’m wondering if this is a time bomb. Is that relay going to fail? What’s the likely mode of failure? One article I saw while googling suggested the relay might get stuck on….not the worst thing, but it would defeat the purpose if that’s what happens. -Adam Get Outlook for iOS <https://aka.ms/o0ukef> -- AF mailing list [email protected] <mailto:[email protected]> http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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