rj11 to usb c connector or adapter

redhead2015

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I want know if it's possible to get a adapter that would be able plug into my rj11 hired wired cable , to usb c so when the Radenso Theia comes out I can run from that cable. Please let me know.
 

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Don't think so. The power requirements are different (12VDC vs 5VDC) . From everything I've heard, you'll have to run a new hardwire cable.
 

Bloovy One

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Not wise. From what they are saying, the point is to power Theia with a better supply of power than typical RJ cables might be able to provide.

Running cables in cars is extremely simple with fingers alone or dull plastic implements. (Watch out for the deployment pattern of side-curtain air bags.)

Here's a thread where ideas are being discussed:
 
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Deacon

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It’s not just a question of a connector. The “RJ11” you’re talking about is providing 12V straight from the vehicle at very low amperage (less than 1A). USB is a completely different standard, operating at 5V, with the Theia being designed with components to deliver up to 3A.

For power alone (no data), you could in theory build a product that takes the 12V DC power source, downconverts it to 5V DC, and provides a USB-A or USB-C output port. No such product exists today that I know of, nor really does it have any reason to exist. Beyond amperage, the length of the wire run from the source to the connector and the size (gauge) of the wire affects the actual voltage delivered at the destination/connector, and even a high quality buck converter is not fully efficient, meaning it’s dissipating whatever power does make it to the RJ11.

Voltage drop is a problem and is also affected by the current being used. For example, let’s say you want to use a small 5A 12V fuse. At the 5A limit, even with 13.8V with the vehicle running, with a 10-foot 26-ga. copper wire voltage delivered is only 9.72V! Not good, and that’s with a high quality phone cord, attainable but not universal. Bump it up (down in size) to 28-ga. wiring, and the voltage delivered is down to 7.31V. Using inexpensive 14-ga. wiring you can get at any auto parts store or even hardware store (and online of course), voltage only drops to 13.55V. Major difference.

For traditional detectors that draw very low power typically (say ~300mA) this is a much easier thing to deal with. At 0.5A, using that same “decent” 26-ga. wire only drops from 13.8V to 13.4V. So at tiny current draws, using tiny wires like that is no problem.

The point is that while theoretically speaking you could build a product to take 12V (nominal) from an existing RJ11 hardwire, drop it to 5V, and provide a USB port out, it’s just not a great idea for this application.
 

kilpatds

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Sorry to thread necro...

USB-C does support 12V output.. but you have to negotiate it, and have a source that's able to provide it. (i.e.: dunno if your new cars USB port will agree to provide 12V.)

Most laptop chargers that use USB-C are using a 12V profile... Up to 3amps for profile 4, 5 amps with profile 5.

So it's certainly possible, although it would be moderately bulky as a prototype, because you'd need a smart adapter
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Friend-of mine more connected that I linked me this:
https://www.amazon.com/gp/product/B08CCX5S96/?tag=rdf0cd0c-20
Some cable crimping required to adapt to RJ11, but should be VERY possible.
 
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Deacon

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Friend-of mine more connected that I linked me this:
https://www.amazon.com/gp/product/B08CCX5S96/?tag=rdf0cd0c-20
That’s very interesting. Thank you for sharing. I wish they’d offer it with a 12V socket for powering CMs, dashcams, radar and lidar systems for testing, etc. I guess you could make your own as long as the brains are in the USB connector itself so you can chop off the barrel connector and wire on a 12V socket.
 

08Z51C6

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And

You can also find the 12 volt to micro USB with dual outputs and dual full size USB outputs.
Post automatically merged:

It’s not just a question of a connector. The “RJ11” you’re talking about is providing 12V straight from the vehicle at very low amperage (less than 1A). USB is a completely different standard, operating at 5V, with the Theia being designed with components to deliver up to 3A.

For power alone (no data), you could in theory build a product that takes the 12V DC power source, downconverts it to 5V DC, and provides a USB-A or USB-C output port. No such product exists today that I know of, nor really does it have any reason to exist. Beyond amperage, the length of the wire run from the source to the connector and the size (gauge) of the wire affects the actual voltage delivered at the destination/connector, and even a high quality buck converter is not fully efficient, meaning it’s dissipating whatever power does make it to the RJ11.

Voltage drop is a problem and is also affected by the current being used. For example, let’s say you want to use a small 5A 12V fuse. At the 5A limit, even with 13.8V with the vehicle running, with a 10-foot 26-ga. copper wire voltage delivered is only 9.72V! Not good, and that’s with a high quality phone cord, attainable but not universal. Bump it up (down in size) to 28-ga. wiring, and the voltage delivered is down to 7.31V. Using inexpensive 14-ga. wiring you can get at any auto parts store or even hardware store (and online of course), voltage only drops to 13.55V. Major difference.

For traditional detectors that draw very low power typically (say ~300mA) this is a much easier thing to deal with. At 0.5A, using that same “decent” 26-ga. wire only drops from 13.8V to 13.4V. So at tiny current draws, using tiny wires like that is no problem.

The point is that while theoretically speaking you could build a product to take 12V (nominal) from an existing RJ11 hardwire, drop it to 5V, and provide a USB port out, it’s just not a great idea for this application.
"No such product exists today that I know of, nor really does it have any reason to exist."
What??
These are made all day long and very popular.
Screenshot_20210322-170905543.jpg
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Deacon

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These are made all day long and very popular.
Yes, I own them and have them installed in my vehicle. They take 12V (nominal) DC from the vehicle and step it down to 5V DC (with USB-A connectors in that case). That is absolutely NOT the same thing as taking in 5V USB on one end and outputting 12V via RJ11 on the other.
 

08Z51C6

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Yes, I own them and have them installed in my vehicle. They take 12V (nominal) DC from the vehicle and step it down to 5V DC (with USB-A connectors in that case). That is absolutely NOT the same thing as taking in 5V USB on one end and outputting 12V via RJ11 on the other.
Look on Banggood.com the website or the app. Might take about 3 weeks to get here but they have a little of everything.
You might have to do some cutting and tying into the cables to get the rj11 connected but I know they have step up/down DC devices like that they have 12 VDC down to 5 VDC and they have 5 up to 12.
It might take a little looking but chances are I bet you'll find it there.
I mostly buy high power flashlights and 18650 rechargeable batteries and other various electronic parts.
Hopefully you can find something that you can piece together to get what you need.
Just trying to be of help.
👍😊
 

Deacon

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Hopefully you can find something that you can piece together to get what you need.
It’s definitely possible. I don’t personally understand the allure when a native 12V source is already available and both cheap and easy to use. But someone here recently even made their own magnetic connector setup stepped to 12V. And just above your post someone pointed out that USB PD supports outputting 12V natively, which is super neat and can put out way more current natively than detectors need (should be enough to run even some radar systems).
 

08Z51C6

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If you do need an extra 5 volt source with a micro USB or mini USB plug on it Amazon and eBay both have an adapter that plugs into your OBD2 diagnostic port of your car and it gets 5 volts from there and then you can run it straight to your detector and it goes off and on with the key and accessory mode so if you're running out of places to pull power that would be a quick and easy plug and Play.
**DC 12-24V Wide Range Input, output: DC 5V, 1.5A. Universal for all vehicles (Car Truck Boat Ferry etc..). Cable length: 11.5FT. https://www.amazon.com/dp/B01H38IO86/?tag=rdf0cd0c-20
Screenshot_20210322-233609.png
 

Deacon

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If you do need an extra 5 volt source with a micro USB or mini USB plug on it Amazon and eBay both have an adapter that plugs into your OBD2 diagnostic port of your car and it gets 5 volts from there and then you can run it straight to your detector and it goes off and on with the key and accessory mode so if you're running out of places to pull power that would be a quick and easy plug and Play.
**DC 12-24V Wide Range Input, output: DC 5V, 1.5A. Universal for all vehicles (Car Truck Boat Ferry etc..). Cable length: 11.5FT. https://www.amazon.com/dp/B01H38IO86/?tag=rdf0cd0c-20 View attachment 175464
The question isn’t how to add 5V options where none existed before. It’s how to get 12V from a an existing 5V outlet. Someone has an existing 5V USB-C plug in their vehicle and wants to figure out how to transform it into a 12V RJ11 jack to power their traditional detector.
 
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08Z51C6

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If you do need an extra 5 volt source with a micro USB or mini USB plug on it Amazon and eBay both have an adapter that plugs into your OBD2 diagnostic port of your car and it gets 5 volts from there and then you can run it straight to your detector and it goes off and on with the key and accessory mode so if you're running out of places to pull power that would be a quick and easy plug and Play.
**DC 12-24V Wide Range Input, output: DC 5V, 1.5A. Universal for all vehicles (Car Truck Boat Ferry etc..). Cable length: 11.5FT. https://www.amazon.com/dp/B01H38IO86/?tag=rdf0cd0c-20 View attachment 175464
Post automatically merged:

Okay I understand what you're looking for now.
This adapter plugs into USB and it steps up to 12 volts. Then you can get line female barrel connector with bare ends and solder that into the rj11 connector for your 12 volts.

Screenshot_20210323-095507074.jpg
Screenshot_20210323-095452016.jpg
Screenshot_20210323-095520585.jpg
 
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08Z51C6

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The USB-a to usb-c (and vice versa)converter plugs are easily found on eBay also.

Hopefully he'll find everything he needs.
👍😊
 

Bloovy One

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If looking for 12 volts, it seems the fusebox could be a shorter route and less points of failure in some cases. For an RJ-11 cable to power a 12 volt detector, just run to the fusebox with a fusetap and you are set. (I prefer to use a purpose-built device for this.)
 

kilpatds

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As others have pointed out, your USB-A port is limited to 5V, and your USB-A-port-that-is-used-for-data is limited at ... 0.5A? Something puny like that. (Your fast charging ports generally allow higher amperage, and yes that's an electrical risk because of people plugging in "pull all the power" devices into your 0.5a plug via a cable that breaks data-detection. You can lose magic smoke that way.)

That's very different than pulling 15V/3A from a USB-C PD port... which is frequently supported, and safe and won't let out any magic smoke.

Please don't hook up A-to-C adapaters and expect to get 15V/3A out of the USB-A plug.


(Above: yes, I'm looking at that barrel adapter and thinking about hooking that into RJ11 with some crimps and shrink tube...)
 

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