Keyboard Shortcuts
Likes
Search
Re: Quality USB-A to USB-C cable to avoid voltage drop
开云体育FYI – I’m also testing the same setup at home, using my big 35amp switching supply.? The USBBuddy (yes, 5V 3A) is not the problem, that I can confirm.? All other variables being the same – 1ft cord, no voltage warnings, longer cord gives low voltage warnings every few seconds.? Tried the same thing with an Anker 6-port USB-A charging brick, with same results.? I had a similar problem in the past with some Pi-3’s I had, and the minute I found a heavier gauge charging cable, the problem went away entirely. ? From my syslogs running the longer cable: ? Jul 11 20:05:59 ham-pi kernel: [389037.212727] Under-voltage detected! (0x00050005) Jul 11 20:06:03 ham-pi kernel: [389041.382230] Voltage normalised (0x00000000) Jul 11 20:16:58 ham-pi kernel: [389696.583122] Under-voltage detected! (0x00050005) Jul 11 20:17:05 ham-pi kernel: [389702.823184] Voltage normalised (0x00000000) Jul 11 20:20:57 ham-pi kernel: [389935.787009] Under-voltage detected! (0x00050005) Jul 11 20:21:04 ham-pi kernel: [389942.026899] Voltage normalised (0x00000000) Jul 11 20:25:59 ham-pi kernel: [390237.391199] Under-voltage detected! (0x00050005) Jul 11 20:26:03 ham-pi kernel: [390241.551137] Voltage normalised (0x00000000) Jul 11 20:26:57 ham-pi kernel: [390295.632010] Under-voltage detected! (0x00050005) Jul 11 20:27:04 ham-pi kernel: [390301.871992] Voltage normalised (0x00000000) Jul 11 20:39:01 ham-pi kernel: [391019.481875] Under-voltage detected! (0x00050005) Jul 11 20:39:05 ham-pi kernel: [391023.642365] Voltage normalised (0x00000000) Jul 11 20:39:24 ham-pi kernel: [391042.362180] Under-voltage detected! (0x00050005) Jul 11 20:39:28 ham-pi kernel: [391046.521950] Voltage normalised (0x00000000) Jul 11 20:39:30 ham-pi kernel: [391048.602143] Under-voltage detected! (0x00050005) Jul 11 20:39:34 ham-pi kernel: [391052.762069] Voltage normalised (0x00000000) ? Since I swapped back to the shorter cable last night, not a single Under-voltage message. ? Jeremy ? From: [email protected] <[email protected]> On Behalf Of Vince A
Sent: Monday, July 12, 2021 5:21 PM To: [email protected] Subject: Re: [RaspberryPi-4-HamRadio] Quality USB-A to USB-C cable to avoid voltage drop ? Dave. Certainly 5.5v wont hurt the pi. But he has a voltage drop because his powerworex is only at max of 3a unit with the 3 ft cord.? Also what I would do if it were me. I would ohm out the 3 ft cord from one end to the other. And see how much resistance there is? That way you can calculate the drop in current by Ohm's law pretty easy. So I don't think it's his USB cord. The cord is only amplifying his situation...? 73 *Jeremy, You got a Powerwerx USBbuddy? 5v 3a??? It looks like Powerworx does sell/have a 4.8a round model (Panel mount dual usb 4.8a)? But first. Have you tried the 3ft cord at home with a 5v wall wart??? I say this because most pi kits come with a 5v 3a wall wart and a 3 ft cord attached? Mine did when I bought the pi kit.? Raise the voltage it will increase the current ? On 07/12/21 3:56 PM, Dave R via groups.io wrote:
-- 73, de Vince KD7TWW In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station power output? - Motorola Corp was formally named "Galvin Manufacturing Corporation" (1928–1947) |