Why would a wireround resistor be needed like with this CAMERA doorbell? - Page 1
Forum section: electronics / general

author: MrMobodies
author_rank: Super Contributor
timestamp: September 10, 2024, 10:40:15 pm
content: As ambiguous as that statement about requring the 30va power supply in a thread I just started.https://www.eevblog.com/forum/chat/conflicting-va-information-about-hardwiring-door-bell-on-eufy-websiie/I Just saw a couple of videos with Youtubers and DIY'ers installing these things recommending to use wireround resistors on this Eufi one (not in the eufi manual) and others, Ring it does) and even searching but can not seem to find the reason WHY.Here it mentions one in the wiring diagram for a RING doorbell camera.No reason why without it.Nothing on the page on the EUFI about requring onehttps://support.eufy.com/s/article/How-to-Hardwire-Your-eufy-Wired-Doorbell-without-an-Existing-WiresNothing in the manual for Eufi:https://ankertechnologycompanyltd.my.salesforce.com/sfc/dist/version/download/?oid=00D5g000004DkWQ&ids=0685g000007fnOnAAI&d=/a/5g000000gHI7/.As1GV_d9jcdpQJySXTTjRP4E8y.ibYvpAVsXB6hQ9g&operationContext=DELIVERY&asPdf=true&viewId=05HJ1000001qy13MAA&dpt=But a Youtube video of someone putting one of these on a Eufi despite it not being required in the manual or website:QuoteComment:QuoteNo reply3:37 in the videoQuote2.05 in the videoQuoteVery frustrating seeing in the comments, in other videos "oh get one", "I got one", "this is what I need and it was very helpful" etc but NOT WHY.Can someone PLEASE explain whether or why this would need a resistor and what it does as to opposed without.ThanksOOps title edit: wirefound resistor NOT fuse.another mistake with the title. CAMERA doorbell.Sorry about this.

author: shabaz
author_rank: Frequent Contributor
timestamp: September 11, 2024, 12:30:29 am
content: Usually the information is pretty vague because the manufacturers hope people use installers rather than do it themselves, and probably the installers might information-hide.At least from Ring doorbell usage (I can't comment on Eufy, but it might be fairly similar) the resistor was only needed on older doorbells.On newer doorbells, it's not needed. Nevertheless, I went for the topology where it's powered through a solenoid (i.e. the solenoid inside mechanical door chimes), so there is a bit of resistance in effect. It sips power, just enough to keep it's internal battery topped up, and that small amount of power doesn't energise the solenoid. The Ring doorbell is designed to act like a short across its power terminals (well, close to a short; I imagine it current-limits) when the user presses the button, so that the mechanical chime can work too. Presumably the older doorbells couldn't do that, so they would have to have a resistor if there was no solenoid in series.I can recommend these parts for a Ring doorbell (specifically the "Ring Video Doorbell 4") because it's been in use for 3 years, with no issue so far.I used a Friedland E3539N transformer, rated at 12V, and you'll see about 22 V AC on the output with a multimeter, and wired the Ring doorbell, and a mechanical (i.e. solenoid) door chime (Honeywell "Ding Dong D117") both in series. That works great.If your doorbell requires a similar voltage and has an internal battery, then there may be a good chance that the items mentioned will work for you.

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 11, 2024, 12:43:19 am
content: Ifthe video doorbellis designed to replace the button and ring the original bell, it needs the resistance of the old bell in the circuit. So if the old bell as been removed, it needs to be replaced with a resistor. Otherwise the "video doorbell" will short out the transformer when it attempts to ring the missing bell. (If old bell wires shorted together instead of a resistor there)

author: MrMobodies
author_rank: Super Contributor
timestamp: September 11, 2024, 12:59:15 am
content: I see so this is to do with the bell. I am not sure what's he's got. I think it was a wireless thing he he told me linked to the base but I'll look tomorrow.Thank you very much for your comments and very helpful.

author: shabaz
author_rank: Frequent Contributor
timestamp: September 11, 2024, 01:00:30 am
content: QuoteExactly that (with the slight caveat that I believe/speculate the newer doorbells current-limit so that there won't be a complete short, and they have in any case confused no end of users because they don't explain it, they just say 'no resistor required', but of course many users will instinctively not want to do that when there's conflicting information, old YouTube videos, etc).I think it's safer all round to just stick in the resistor if there's ambiguity in the instructions of whatever doorbell is being installed, or simply buy a mechanical chime and stick that in series (it doesn't usually hurt to have the extra sound! : )The first week or so, the battery level needs to be monitored (at least I had to do that with Ring) since it charges slowly, and when it's close to 100%, then it tends to remain approximately there (mine is currently at 95%) and will vary slightly depending on how often it is consuming more power (e.g. if it's facing a busy road maybe), but overall, I've never had the battery deplete (it is not facing a road). It's probably not good for the battery to be charged so fully always, but as mentioned it's lasted 3 years so far, so that's not too bad.

author: EPAIII
author_rank: Super Contributor
timestamp: September 11, 2024, 10:50:41 am
content: Best argument against getting a Ring or Eufi video doorbell I have seen. Thanks for the heads-up.

author: Zucca
author_rank: Unknown
timestamp: September 11, 2024, 05:53:30 pm
content: worth to mention that in my ring installation I was required to put a "white box" in parallel to the bell.I assumed it is for trickling energy (lowering the bell impedance) to the ring so that the ring battery can be charged.

author: exe
author_rank: Unknown
timestamp: September 11, 2024, 07:27:04 pm
content: I can only think of power dissipation. For 24V transformer, 2k resistor will dissipate ~0.3W in the worst case. That's not insignificant. On the other hand, most wire-wound resistors have power rating at least 1W even without heatsink. So, that might be the reason.Of course, it's better to ask vendor, but playing a guess game is much more interesting)

author: Xena E
author_rank: Frequent Contributor
timestamp: September 11, 2024, 07:38:39 pm
content: When I saw the title I thought it was similar to mine where a high power ww resistor is used to stop condensation within the camera housing...Quite clearly not!

author: shabaz
author_rank: Frequent Contributor
timestamp: September 11, 2024, 08:31:30 pm
content: Quote from: Zucca on September 11, 2024, 05:53:30 pmI can imagine that indeed being the case if the specific bell is either electronic, or has high resistance. The simpler bells (the ones that only have a solenoid pretty much! such as that Honeywell model suggestion) are candidates for not requiring any additional resistor.The current required to flow through the Ring device is low since it charges at such a slow rate, but it will then try to look like a low resistance for a short period when the user presses the button.

author: MrMobodies
author_rank: Super Contributor
timestamp: September 11, 2024, 11:43:45 pm
content: There are no wires going to it. He has a wireless sounder a base and that's it.The screws were so small it kept on slipping out or working their they out on the slightest movement.Went home to get some clips but found I didn't have the right size which seemed bigger than the screw so I clamped the conductors between two washers with some longer screws that were a a few mm longer to get the thread in as much as possible. I suppose I could have put the clips in with a washer on the top to hold it in place.I found it very easy to screw the conductors without them moving or slipping out during tightening and sit seems to hold it in very tightly.I used the, Zyxel JAA-1601000F 16vac 1000mah 16va transformer but forgot to do one thing which I will do tomorrow. Connect a volt meter up, have the owner ring the bell to see it if shorts out. With it connected it shows on the APP that it is charging. It makes a very silent buzzing sound when I put my head near it but it didn't seem to get warm after a few hours. From a watt measuring plug it seems to draw 2watts on it's own and 2.2 to 2.4watt when connected up.I noticed something that if there is no load it is about 18v but with the video doorbell connected up the voltages goes up to like about 22v.I got a response this morning and I didn't know Anker owned Eufi.QuoteSo wraparound resistor is not a requirement.This again:QuoteIn contrary to:QuoteConflicting VA information about hardwiring door bell on eufy websitehttps://www.eevblog.com/forum/chat/conflicting-va-information-about-hardwiring-door-bell-on-eufy-websiie/Quotehttps://support.eufy.com/s/article/Hardwire-Your-2K-Battery-Doorbell-for-Continuous-Charging-1617357656298QuoteThe 16v one I connected up is 1000 mah, 200 mah more than what's required above on that part of their website.https://www.reddit.com/r/EufyCam/comments/rm66i5/2k_wired_doorbell_power_requirements/QuoteIt seems they are not keeping the information clear across the board or consistent between technical support individuals.

author: shabaz
author_rank: Frequent Contributor
timestamp: September 11, 2024, 11:51:00 pm
content: Looks like good progress.I think they copied the rear to be like the Ring device (or vice-versa), they have a similar two screws on that flat surface.The Ring device came with two short wires though, with one end containing forked lugs to slip under the screw heads. There were some wire nuts for the other end to attach to the existing wiring, I think I just soldered and heat-shrinked those ends.

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 12, 2024, 12:45:33 am
content: Quote from: MrMobodies on September 11, 2024, 11:43:45 pmThat's perfectly OK. The video doorbell will only draw the current (mA) that it requires. As long as the adapter can provide more than the minimum required, you are good to go.