Re: [neonixie-l] Re: Q: Active full-wave rectifiers

['jf...@my-deja.com' via neonixie-l]

If all you want is to get 5Vdc rom the mains, a USB charger seems like a 
very attractive option.  They are usually less than US$5 and occupy about 
1cu in (plus the power plug).  My initial concern would be safety 
isolation, but some of these will surely be UL listed or CE qualified.

However, if you are doing an engineering laboratory exercise requiring 
using a 6.3vac source then this is almost interesting.  It should be 
possible to build a buck-boost regulator that will tolerate a very wide 
range of unregulated inputs.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/c9e523cc-fd8d-473e-a7b3-4a41b6f5ab2a%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Re: Q: Active full-wave rectifiers

[gregebert]

I tend to use higher voltage transformers, in the 8-12VAC range, full-wave 
rectifiers + filter-cap, then use switching-regulators that are 
pin-compatible replacements for the popular LDO regulators. They are 90%+ 
efficient, and therefore generate almost no measurable heat. 

If the current is really low, say 50mA or less, I'll use an LDO.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/1a87ed22-b3a4-47ce-9c18-c1233c1c5582%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

RE: [neonixie-l] Re: Q: Active full-wave rectifiers

[johnk]

And I’d ask about mains stability.

Was half-wave ruled out?

 

John K

 

 

From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of petehand
Sent: Monday, 25 March 2019 18:43
To: neonixie-l
Subject: [neonixie-l] Re: Q: Active full-wave rectifiers

 

I would use four discrete schottky diodes in a bridge, and a low dropout 
regulator like an LM1117. The 5V version of the LM1117 regulates down to 6.2V 
input and delivers 800mA.

 

 

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/1fd82233-c90d-45da-89a0-1d35d17df93c%40googlegroups.com
 

 .
For more options, visit https://groups.google.com/d/optout.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/001201d4e304%24487d69e0%24d9783da0%24%40internode.on.net.
For more options, visit https://groups.google.com/d/optout.

Re: [neonixie-l] Re: Q: Active full-wave rectifiers

[David Forbes]

I'm surprised that you can't just use the Schottky diode bridge, a rather
large filter capacitor and an LDO regulator chip. What components are you
using, and what's the lowest voltage you see at the input to the regulator?


On Sun, Mar 24, 2019, 10:27 AM Dekatron42  wrote:

> In the circuit with the FDMQ8205 that you refer to they are connected in a
> POE circuit (Power Over Ethernet) where they make use of DC-voltages for
> the power and AC-voltages via the transformers for the data-transmissions -
> so the FDMQ8205 actually only work as polarity protection in that circuit
> and not as full-wave rectifiers.
>
> There is an old Elektor circuit here:
> http://projectcircuit4u.blogspot.com/2010/04/power-mosfet-active-bridge-rectifier.html
> that you might be able to use in some combination with the FDMQ8205.
>
> /Martin
>
> --
> You received this message because you are subscribed to the Google Groups
> "neonixie-l" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to neonixie-l+unsubscr...@googlegroups.com.
> To post to this group, send email to neonixie-l@googlegroups.com.
> To view this discussion on the web, visit
> https://groups.google.com/d/msgid/neonixie-l/1d480f1e-ef4a-4343-8bcd-af999c8d5236%40googlegroups.com
> 
> .
> For more options, visit https://groups.google.com/d/optout.
>

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcqCTq4TiSd7F-XxEXo21AyXu%3DSzUaEx4FhET0B9RiVAw%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.