[arm-allstar] 13 V to 5V PI pwr supply

[David McGough]

Well, you have to remember that these days all our ham rigs are full of 
voltage regulators--including switchers and various types of linear 
regulators, like potentially cantankerous LDO's (Low Drop Out linear 
regulators). The modern bench-top switcher (like the Astron, Samlex, etc.) 
is a very, VERY stable beast.

Every case I've had of flaky power supply behavior, at least where the
supply wasn't broken, has been traced to various ground faults or RF--and
sometimes it doesn't take a lot of RF to make a supply crow-bar, etc.

...My big interest with this thread is there is a always a new 
failure mode, waiting to sneak up and bite you in the @$$ ...

73, David KB4FXC



On Tue, 13 Oct 2015 petem001 at gmail.com wrote:

> If my memory is right, using a linear regulator after a switching power supply is not a good thing..
> 
> 
> 
> From: James R. Pilgram 
> Sent: Tuesday, October 13, 2015 5:45 AM
> To: arm-allstar at hamvoip.org 
> Subject: Re: [arm-allstar] 13 V to 5V PI pwr supply
> 
> Tonight I was setting up a Raspberry Pi2 with a simplex CDM750 and converted usb fob getting all kinds of screwy problems. The Fob was going in and out and failing. 
> 
> In my case, I was using a Astron SS-25 switching power supply to power the radio and one of the 12 to 5 volt switching modules to power the Pi. The radio was going crazy, the fob was going crazy, the Pi was going crazy and the supply crow-barred. I grabbed another supply, A Samlex SEC1223 switching supply and got the same issues. We were having a similar issue with another node on Maui only he was using a DMK-URI and a switching supply Powering a 12 to 5 volt module and a simplex radio from the same supply. 
> 
> Turns out the guy on Maui solved the problem with a different power supply for the Pi not hooked to the switching supply running his radio. I'll be trying again tomorrow with a linear supply. I never had a problem with a linear supply or a nice big battery bank. 
> 
> Jim NH6HI 
> 
> 
> On 10/10/15 03:47, REDBUTTON_CTRL wrote:
> 
>   Well, how are you running them on a 12v battery or 13.8 power supply with battery back up? 
>   Are they at home or at repeater site?
>   Jon VA3RQ
> 
>   On 10/9/2015 1:13 AM, Eric Harrison wrote: 
>           Well not much more I can say. They are made in China and are cheap and like all electronics are subject to failure's! 
> 
>           Eric
> 
>           N7JYS
> 
> 
>           Sent from Yahoo Mail on Android
> 
> 
> ----------------------------------------------------------------------
>                 From:"David McGough" mailto:kb4fxc at inttek.net
>                 Date:Thu, Oct 8, 2015 at 11:35 PM
>                 Subject:Re: [arm-allstar] 13 V to 5V PI pwr supply
> 
> 
> 
>                 Hi Eric,
> 
>                 Interesting that you're having failures. I'd like to hear more about the 
>                 failed systems?
> 
>                 I've been running -many- (more than a dozen at this point) supplies of
>                 this style, on many projects, with no failures.
> 
>                 73, David KB4FXC
> 
> 
>                 On Thu, 8 Oct 2015, Eric Harrison wrote:
> 
>                 > Just FYI I have been using this same DC to DC converter on several up my pi's and already had 2 of them fail after a few months of use.
> 
> 
>                 Eric
> 
>                 N7JYS
> 
>                 Sent from Yahoo Mail on Android
> 
>                 From:"jim.pilgram at gmail.com" <jim.pilgram at gmail.com>
>                 Date:Thu, Oct 8, 2015 at 7:25 PM
>                 Subject:Re: [arm-allstar] 13 V to 5V PI pwr supply
> 
>                 I have been using these on our system since Doug put the RP2 build out and have not had any problems with the over 1 dozen units out there. Love them and the price. 
> 
> 
>                 Sent from my BlackBerry 10 smartphone on the Verizon Wireless 4G LTE network.
> 
>                 From: Jacques St-Pierre
> 
>                 Sent: Thursday, October 8, 2015 14:12
> 
>                 To: arm-allstar at hamvoip.org
> 
>                 Reply To: ARM Allstar
> 
>                 Subject: [arm-allstar] 13 V to 5V PI pwr supply
> 
> 
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