The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "gert baars"
Subject: Re: High Voltage Input into 78xx
X-Newsreader: Microsoft Outlook Express 5.00.2919.6600
X-MIMEOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
Date: Thu, 31 Oct 2002 07:21:30 GMT
NNTP-Posting-Date: Thu, 31 Oct 2002 08:21:30 MET
Organization: Chello Broadband
With 35V input and 1A current the 7805 will have to dissipate 30 Watts. This
will only work for a few seconds
before temperature protection gets active.
An option is to use 2 or more regulators in series, like an 7824 (max 38V
in) and an 7815 (max 30V in) and
finally the 7805 and mount them on one fairly large heatsink.
"Shaun Davy" schreef in bericht
> Just wondering if anyone could point me in the direction of how i could go
> about running a +5V regulator off a 35V DC input (24VAC) and draw around
> 250mA mark and if possable for future projects upto .5A or 1A.
> Should i just use a normal 7805 and strap a big heatsink to it to
> all that heat or is there a better more efficient way?
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup