Looking for resistor

[keeney123]

Re: Looking for resistor

Yes 40VA is 40 watts. 40 VA is 40 volts times amp. Volts times amps is watts. I think in another thread or even this thread I post where you can by a 16 volt 10VA at Home Depot for $8. I would not use a transformer that is the wrong rating for the door chime as it may not work at all. I would still check the wires with a meter as some people may of connected them wrong. Any good electrician would do this check. You always check voltages or current on the largest scale and then go to a smaller scale if you can not get a reading. I went to your link but there was no pictures.

If you have no door bell or wires on the outside of the home then you will need to run wires to the outside of the home. You will need what they call a fish. This is a reel of solid very stiff wire with a loop at the end of it. It is contain in a plastic container than can be reeled out or up depending on what you need. You will fish this wire up from your basement or down from your attic. In the basement you may have to drill a hole in a stud to get to the interior wall. You will also have to drill another hole in the outside wall where you want the door bell. That is where the wires will come through. You fish this stiff wire to this hole. This will require two people. One looking for the wire and one doing the fishing. When you get the fish to the outside wall you then strip the end of the two wires your are going to use for the door chime. Then you twist the wire end and loop them them through stiff wire loop and twist them back on to themselves and lastly you tape them very tight and smooth so they do not slip off. The next thing is to pull the wire. you will then bring them to the chime and then to the transformer. Or you could get a wireless door bell. You will have a door bell on the outside of the door. This has a AA or AAA battery which can be replaced easy. It also last a long time. The chime you plug in to a wall outlet somewhere near the door on the inside of you house.
Lastly if the wiring is screwed up in your house then make sure you have smoke and fire alarms in each room. When you can afford an electrician, get a "master" electrician first to come to your house to see what needs to be done and gives you a cost break down on doing it. Then do one thing at a time until you get is completed.

[Almighty1]

Re: Looking for resistor

So 40VA = 40 watts. or P= V*A therefore P/V=A Where P is power in Volt * Amps better known as Watts. 40Watts/24Volts= 1.67 Amps now we use the formula V=I*R where I is current and R is resistance We rearrange this formula to V/R=I that is 24volts/25ohms= 0.96 amps. Now we use another equation that may be derived from P=V*I with substitution to get P=I^2*R
Of course you will notice that A and I are the same "current". So the equation becomes P=0.96^2*25, this then gives you 23.04Watts or VA.
You should check the voltage on the wires to the transformer before you disconnect the wires to make sure the voltage side you are disconnecting is the 24 volt side and "not" the 120 Volts side. Make sure you take one side off at the time making sure not to short wires across transformer. Or you can have someone stay with a meter measuring the voltage on the transformer and another person can start flipping breakers until to find the one that cuts the power off to the transformer. Then do the below step.

To check your door bell wires. First detach wires on transformer. Undue the door bell and connect both wires go back to transformer using an OHM Meter measure the resistance between the two detached wires that go to the door bell. Your resistance will be low around 25 ohms which is the chime coil. This is a continuity check. Also, before you measure the Ohms switch to Voltage scale and make sure you have no DC volts or AC volts between the wires you are going to measure in OHMs.

Thanks for the reply. So is 40VA really 40 Watts or 23 Watts? The transformer is actually a GE 10V 5VA, what would happen if I use a door chime that normally requires 16V 10VA, will it still work but just not be as loud since it seems like both the voltage and the VA is lower. I know which side is the 120VAC side as that is the one that goes into the AC wires while the other side usually in the black/white/green configuration while the lower voltage side is always the one that goes into the small screw terminals with the markings of the LOAD and the 10VAC 5VA.

If you see the other thread, my post https://www.badcaps.net/forum/showpo...80&postcount=7

I actually do not have a door bell button or a door bell so there is nothing connected on the other end of the wires which was the reason I asked how to check if the wires found where the door chime and door bell is supposed to be is actually connected to the transformer as all the wires are sealed inside the wall so I don't know if the wires are connected all the way. Normally in a circuit, it will require two wires that atleast are connected on the other end to something to make testing easier but since I do not have a door bell button and a door chime, my original question was how do I test the wire at the location where the door chime was supposed to be as I am trying to determine which wire goes to the transformer which would be connected while the other wire is not connected at the other end as that one is supposed to go back to the door bell.

[Almighty1]

Re: Looking for resistor

First, as was already mentioned in the other thread, you need to get a licensed electrician in there to correct all of the serious wiring issues.

Second, I suggest you find an experienced LV/alarm installer. The conditions you have going on puts this task over your head..and the use of that resistor can create a safety hazard if not done correctly.

The time that will be saved and the reduction/elimination of the hazards present will be worth the extra cost.

Not when the cost is over $10k as all the walls will need to be torn down. I will already be spending $650k+ in the remodeling process alone, licensed electricians and even contractors had looked at the issue as this was even part of the home inspection process before the home was purchased 7+ years ago. They basically all said that to fix the problem, all the walls need to be taken down and demolished as that will require a permit on it's own since everything is in sealed walls now which is why they all suggested to just have it done during the remodeling process since everything will be taken down at that point anyways. I am not planning to use the resistor on the existing wiring as I want to avoid that due to what was mentioned by you and others about the safety hazard. This is why I will just have a plug-in transformer to the wall directly to the doorbell which is about 10 feet away and the reason for the resistor.

[keeney123]

Re: Looking for resistor

Good point but usually the higher voltage has higher current, atleast on transformers. Since there are plug-in transformers sold by Parts Express that is 40VA in current at 24VAC except ofcourse the battery is DC and not AC so not sure what happens inside the ring.com doorbell internally as I know at the standard 500mAh 5vdc using MicroUSB, it will take 10 hours to charge but if the charger is a USB charger at 1700mAh, it will take roughly 3.5 hours or so to fully charge.

http://www.parts-express.com/parts-e...rmer--120-1175

So 40VA = 40 watts. or P= V*A therefore P/V=A Where P is power in Volt * Amps better known as Watts. 40Watts/24Volts= 1.67 Amps now we use the formula V=I*R where I is current and R is resistance We rearrange this formula to V/R=I that is 24volts/25ohms= 0.96 amps. Now we use another equation that may be derived from P=V*I with substitution to get P=I^2*R
Of course you will notice that A and I are the same "current". So the equation becomes P=0.96^2*25, this then gives you 23.04Watts or VA.
You should check the voltage on the wires to the transformer before you disconnect the wires to make sure the voltage side you are disconnecting is the 24 volt side and "not" the 120 Volts side. Make sure you take one side off at the time making sure not to short wires across transformer. Or you can have someone stay with a meter measuring the voltage on the transformer and another person can start flipping breakers until to find the one that cuts the power off to the transformer. Then do the below step.

To check your door bell wires. First detach wires on transformer. Undue the door bell and connect both wires go back to transformer using an OHM Meter measure the resistance between the two detached wires that go to the door bell. Your resistance will be low around 25 ohms which is the chime coil. This is a continuity check. Also, before you measure the Ohms switch to Voltage scale and make sure you have no DC volts or AC volts between the wires you are going to measure in OHMs.

[mxslick]

Re: Looking for resistor

First, as was already mentioned in the other thread, you need to get a licensed electrician in there to correct all of the serious wiring issues.

Second, I suggest you find an experienced LV/alarm installer. The conditions you have going on puts this task over your head..and the use of that resistor can create a safety hazard if not done correctly.

The time that will be saved and the reduction/elimination of the hazards present will be worth the extra cost.

[Almighty1]

Re: Looking for resistor

As can be seen in the other thread, doing it the doorbell chime route is very risky since I have to change out the transformer... So it seems like the resistor idea is still the better bet so would greatly appreciate anyone's help in picking out a resistor that will work.

[Almighty1]

Re: Looking for resistor

Good point but usually the higher voltage has higher current, atleast on transformers. Since there are plug-in transformers sold by Parts Express that is 40VA in current at 24VAC except ofcourse the battery is DC and not AC so not sure what happens inside the ring.com doorbell internally as I know at the standard 500mAh 5vdc using MicroUSB, it will take 10 hours to charge but if the charger is a USB charger at 1700mAh, it will take roughly 3.5 hours or so to fully charge.

http://www.parts-express.com/parts-e...rmer--120-1175

[stj]

Re: Looking for resistor

now stop right there,
a increasing voltage wont charge a battery faster, it will heat it up till it bursts or burns.

the speed a battery charges is controlled by the current, not the voltage.

[Almighty1]

Re: Looking for resistor

Only problem is I hope the wires are still connected because the wiring in the house is messed up. The telephone termination for example is somewhere inside the wall so AT&T basically cut the wire outside and just mounted a new box outside and the only phone jack inside the house is dead. All I can do is run CAT6 cable from the box on the outside wall to where I need a phone jack using a existing hole from outside the wall. It just seems like a higher voltage would be better because it would charge the battery faster. I guess if all else fails, then I will need to use the transformer with doorbell wire and plug it into a AC Outlet. My concern if I go that route is what can I use to house the transformer so no one gets shocked should they touch it accidentally as I know there are plug-in transformers that are 24VAC 40-50VA from places like Parts Express but then I can pickup a Heath-Zenith 24VAC 20VA Transformer from a local hardware store for $5.00.

Are there any good brands of resistors available that is reliable since just like capacitors, I would prefer something like Panasonic, Nichicon, Chemi-con for example.

To be honest, I do want to go the chime route if possible since it seems easier and the chime will be louder than the Ring Chime that I'm using now which is only connected by WiFi that I can't hear it most of the time but if the existing wires don't work, then I'll have to do a run from the AC Outlet to the transformer with the resistor which is about a 25 feet or less run.

[budm]

Re: Looking for resistor

They are using the resistor when you are not going to use the chime, if you have the chime then you do not need the resistor, if the chime come with the step down transformer then you do not need to use the new transformer if the old one is good and has the correct AC Voltage to match the new chime and wire it up as shown for single switch location.

[Almighty1]

Re: Looking for resistor

Per this link, I don't think it can really use that much power as the power seems to be more for the doorbell's chime itself as the power is more for charging the battery...
https://support.ring.com/hc/en-us/ar...attery-Powered

[Almighty1]

Re: Looking for resistor

20~50W Resistor? How much power does this unit require? You should worry about dissipating the 20~50W of power in tight space.
So you are not going to use a new door chime? https://www.badcaps.net/forum/showthread.php?t=52762
https://cdn.badcaps-static.com/pdfs/...ad85f6e9e4.pdf

No idea how much power the unit really needs because normally it can be powered by the battery which is charged using MicroUSB so the power requirement is not high. It's just that if I'm traveling, I can't be there physically to charge the doorbell weekly due to the motion detection of 600-700 events weekly. The door chime is a option without the resistor except I do not know if the existing wiring even works or not as the only thing left is the wires where both the door bell button and door chime is supposed to be.
I can see that it doesn't matter which wire is the transformer and which one is the chime for the door bell button but I still haven't figured out how to figure out which is the transformer wire where the chime is.
I need to make sure the wires actually has voltage first before doing it without the resistor which would make it a whole lot easier. The house will be remodeled and everything will be torn down in a year or so, so anything is really only going to be a temporary solution. I can easily get a door chime kit which includes the transformer and the chime and even 2 doorbell buttons but ofcourse like I said, it's figuring out the transformer wire for the
chime itself that seems to be hard as I tried a Digital MultiMeter on both wires with one on red and one on black and not seeing any voltage because only one wire is supposed to be connected to the transformer at where the chime is and where the doorbell button is. The other thing is rewiring the doorbell and chime is not easy as the wires all go straight inside the wall and you can't pull or push the wires either because they patched up the entire wall where the wires are as the house was being remodeled when the former owner got foreclosed on.

[budm]

Re: Looking for resistor

It is power through the door chime, so for them to use 25 ~ Ohms 20 ~50W resistor it must have quite AC drops on the resistor to dissipate that much power, you can calculate V drops on that resistor.
So just assume safety margin so they double up on the Wattage of the resistor, so it will be 10W or 25W of power dissipation on the resistor.

[eccerr0r]

Re: Looking for resistor

Looking at the docs a bit, the resistor isn't there for dropping, it's there in lieu of the doorbell chime... must be some other indication that the system was activated.

I suppose if you have a 24V relay you could use that instead of the chime/resistor too. However I suspect the circuitry is assuming an inductive load and hence the wirewound. Without knowing what the actual circuitry is in the device, who knows...

[budm]

Re: Looking for resistor

20~50W Resistor? How much power does this unit require? You should worry about dissipating the 20~50W of power in tight space.
So you are not going to use a new door chime? https://www.badcaps.net/forum/showthread.php?t=52762
https://cdn.badcaps-static.com/pdfs/...ad85f6e9e4.pdf

[stj]

Re: Looking for resistor

http://www.digikey.com/product-detai...5R0-ND/1646203

where is cheapest for delivery though?

[Almighty1]

Greetings everyone:

I have a ring.com doorbell and it seems like to hardwire the doorbell so I don't have to take it off the wall to charge it weekly, I need a transformer and a resistor as seen here:
https://support.ring.com/hc/en-us/ar...a-doorbell-kit

So basically I need a 25 to 33 Ohm/20 to 50 Watt wirewound resistor, does anyone have any recommendations on what brands/parts are suitable for this and also for the doorbell wire, can I just use 18 or 20 guage speaker wire? Also, is there a reason to use a wirewound resistor instead of a film resistor? Since this will be outside, what can I use to cover up the wires?

Thanks!