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Posted by: jim_hoyland Mar 23 2024, 10:16 AM

What is the voltage output at the end of a USB connector. The input plug is at the cig lighter receptacle.
I assumed it would be 12v, but, heard it might be 5 v ???


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Posted by: FlacaProductions Mar 23 2024, 10:48 AM

USB power is always 5v

USB 2.0 - 5V - Max output 2.5W
USB 3.0 / USB3.1 - 5V - Max output 4.5W

Posted by: windforfun Mar 23 2024, 10:49 AM

Posted by: jim_hoyland Mar 23 2024, 11:31 AM

Thanks, thought it

Posted by: SirAndy Mar 23 2024, 12:34 PM

Looks like USB can go up to 48V for power delivery but is 5V otherwise:
https://en.wikipedia.org/wiki/USB






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Posted by: worn Mar 23 2024, 07:34 PM

QUOTE(jim_hoyland @ Mar 23 2024, 09:31 AM)

Posted by: jim_hoyland Mar 23 2024, 08:04 PM

QUOTE(worn @ Mar 23 2024, 06:34 PM)

QUOTE(jim_hoyland @ Mar 23 2024, 09:31 AM)

Thanks, thought it

I did it myself for a USB outlet. Turns out that I had to make resistor connections to keep the data pins at the right voltages to suit Apple.

Posted by: fixer34 Mar 24 2024, 08:01 AM

QUOTE(jim_hoyland @ Mar 23 2024, 09:04 PM)

QUOTE(worn @ Mar 23 2024, 06:34 PM)

QUOTE(jim_hoyland @ Mar 23 2024, 09:31 AM)

Thanks, thought it

I did it myself for a USB outlet. Turns out that I had to make resistor connections to keep the data pins at the right voltages to suit Apple.

What size resistor would drop 12v to 5v. ?

Posted by: windforfun Mar 24 2024, 08:52 AM

QUOTE(jim_hoyland @ Mar 23 2024, 07:04 PM)

QUOTE(worn @ Mar 23 2024, 06:34 PM)

QUOTE(jim_hoyland @ Mar 23 2024, 09:31 AM)

Thanks, thought it

I did it myself for a USB outlet. Turns out that I had to make resistor connections to keep the data pins at the right voltages to suit Apple.

What size resistor would drop 12v to 5v. ?

Posted by: Montreal914 Mar 24 2024, 09:42 AM

Why not use something like this?

First one that came up with initial search, I am sure many other can be found.



https://www.amazon.com/Cllena-TOYOTA-Dashboard-Charger-1-2A-2/dp/B01CTOKI06/ref=asc_df_B01CTOKI06/?tag=hyprod-20&linkCode=df0&hvadid=312111908612&hvpos=&hvnetw=g&hvrand=16235771559141942065&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031212&hvtargid=pla-569986511170&mcid=9c35e35f92293ce8be068293b5f1c0cc&gclid=CjwKCAjwnv- vBhBdEiwABCYQA_fRoZDU6yP5iHEThWTvhzOkudJriyG6qMjPUWlUAAxq8RGEA748TxoCCSkQAvD_BwE
&th=1

Posted by: Retroracer Mar 24 2024, 10:16 AM

@http://www.914world.com/bbs2/index.php?showuser=643 a better question might be: what device are you trying to get power to?

- Tony

Posted by: lierofox Mar 24 2024, 11:22 AM

A USB charger that plugs into a cigarette lighter plug already does the voltage step down process for you.

Unless a device plugged into the USB port specifically requests a higher voltage (like a tablet, or a laptop), USB will ALWAYS default to outputting 5v.

Posted by: jim_hoyland Mar 24 2024, 01:52 PM

QUOTE(Retroracer @ Mar 24 2024, 09:16 AM)

Posted by: windforfun Mar 24 2024, 02:54 PM

QUOTE(jim_hoyland @ Mar 24 2024, 12:52 PM)

QUOTE(Retroracer @ Mar 24 2024, 09:16 AM)

@http://www.914world.com/bbs2/index.php?showuser=643 a better question might be: what device are you trying to get power to?

- Tony

I’m going to power a HUD directly to the fuse panel. The HUD say max voltage is 5v.
So, I want to step the v down under the dash.
This is A MPH HUD, not the fancy ones that plug into an OB receptacle

Posted by: jim_hoyland Mar 24 2024, 03:23 PM

QUOTE(windforfun @ Mar 24 2024, 01:54 PM)

QUOTE(jim_hoyland @ Mar 24 2024, 12:52 PM)

QUOTE(Retroracer @ Mar 24 2024, 09:16 AM)

@http://www.914world.com/bbs2/index.php?showuser=643 a better question might be: what device are you trying to get power to?

- Tony

I’m going to power a HUD directly to the fuse panel. The HUD say max voltage is 5v.
So, I want to step the v down under the dash.
This is A MPH HUD, not the fancy ones that plug into an OB receptacle

https://en.wikipedia.org/wiki/Voltage_divider

Posted by: SirAndy Mar 24 2024, 03:39 PM

QUOTE(jim_hoyland @ Mar 24 2024, 12:52 PM)

Posted by: fixer34 Mar 24 2024, 05:24 PM

No affiliation, but I don't think you can build something for this price...

https://www.temu.com/ul/kuiper/un9.html?subj=goods-un&_bg_fs=1&_p_jump_id=894&_x_vst_scene=adg&goods_id=601099541519533&sku_id=17592321968927&adg_ctx=a-87d395fc~c-9ec4c41e~f-f481d604&_x_ads_sub_channel=shopping&_p_rfs=1&_x_ns_prz_type=-1&_x_ns_sku_id=17592321968927&mrk_rec=1&_x_ads_channel=google&_x_gmc_account=647900107&_x_login_type=Google&_x_ads_account=1919904652&_x_ads_set=21019380395&_x_ads_id=159035039019&_x_ads_creative_id=690830436449&_x_ns_source=g&_x_ns_gclid=CjwKCAjwnv-vBhBdEiwABCYQA_-8qa5zjSSsPD-L_QNLFO26VMJfoGAgqMyP9dWQ-anYV0bABlG3YBoCb5oQAvD_BwE&_x_ns_placement=&_x_ns_match_type=&_x_ns_ad_position=&_x_ns_product_id=17592321968927&_x_ns_target=&_x_ns_devicemodel=&_x_ns_wbraid=Cj4KCAjw-_mvBhBEEi4AtqjNFwXcyCwg-sf4in7jKxbYgZXl5Oxh9KkpBW9x1ckV8TE5HzLnGqEWCnO0GgIuIg&_x_ns_gbraid=0AAAAAo4mICF8EafLEsI2wpNawvnAmrgcs&_x_ns_targetid=pla-2310464807724&gad_source=1&gclid=CjwKCAjwnv-vBhBdEiwABCYQA_-8qa5zjSSsPD-L_QNLFO26VMJfoGAgqMyP9dWQ-anYV0bABlG3YBoCb5oQAvD_BwE

Posted by: r_towle Mar 24 2024, 05:32 PM

Buy a 5 dollar cigarette lighter converter and break it open.
There will be the circuit and resistor

Posted by: technicalninja Mar 24 2024, 06:08 PM

QUOTE(fixer34 @ Mar 24 2024, 06:24 PM)

Posted by: FlacaProductions Mar 24 2024, 06:45 PM

Why not just use the power supply that came with it?

Posted by: jim_hoyland Mar 24 2024, 06:47 PM

QUOTE(FlacaProductions @ Mar 24 2024, 05:45 PM)

Posted by: SirAndy Mar 24 2024, 06:55 PM

QUOTE(jim_hoyland @ Mar 24 2024, 05:47 PM)

QUOTE(FlacaProductions @ Mar 24 2024, 05:45 PM)

Why not just use the power supply that came with it?

The power cable has USB connectors at each end; I want to power it directly off the fuse panel.

Posted by: SirAndy Mar 24 2024, 07:03 PM

QUOTE(SirAndy @ Mar 24 2024, 05:55 PM)

QUOTE(jim_hoyland @ Mar 24 2024, 05:47 PM)

QUOTE(FlacaProductions @ Mar 24 2024, 05:45 PM)

Why not just use the power supply that came with it?

The power cable has USB connectors at each end; I want to power it directly off the fuse panel.

Ok, then get a USB adapter that normally plugs into the cigarette lighter and simply connect 12V from the fuse panel to the center contact and ground to the side contacts on that adapter.
That way, you can simply use the usb cable that came with your HUD and everything fits with no other modifications needed.

Posted by: jim_hoyland Mar 24 2024, 07:08 PM

Found this on Amazon:


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Posted by: SirAndy Mar 24 2024, 07:13 PM

That should work.
And if you're running this off the fuse panel, make sure you're piggy-backing off a switched terminal so the power to your HUD is turned off when the key is off.

Otherwise, that thing will drain your battery in a hurry ...

Posted by: FlacaProductions Mar 25 2024, 08:39 AM

or one of these:
https://www.amazon.com/gp/product/B01FJ8OXX2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

red to + and black to ground. plug in the adapter andy shows in post 23 and bob's your uncle.

put two female spade connectors on it, get two piggybacks, pull the ashtray, reach in and use the connections on the back of the cigarette lighter. one most forward in the car is + and the one on the side is ground.