Path: utzoo!attcan!uunet!lll-winken!ubvax!weitek!amdcad!phil
From: phil@amdcad.AMD.COM (Phil Ngai)
Newsgroups: sci.electronics
Subject: Re: 7805 regulator
Message-ID: <22117@amdcad.AMD.COM>
Date: 17 Jun 88 00:34:05 GMT
References: <592@picuxa.UUCP> <5030002@hpvcla.HP.COM>
Reply-To: phil@amdcad.UUCP (Phil Ngai)
Organization: Advanced Micro Devices
Lines: 17

In article <5030002@hpvcla.HP.COM> johne@hpvcla.HP.COM (John Eaton) writes:
>< I have a question about the MC7805 5V 1A regulator. Can you parallel
>< two of these devices together to derive a higher current?
>In a word, NO. Unless they are extremely well matched then one will wind up
>with most of the load and the other will have very little. The best way is

I had a friend in college do this. I was skeptical but it worked fine. 

What is the problem with one taking most of the load? They are over
current and temperature protected anyway.

>to use a 7805 for the regulation and an external power transistor for the 

Now you don't have the protection that the 7805 has.
-- 

I speak for myself, not the company.
Phil Ngai, {ucbvax,decwrl,allegra}!amdcad!phil or phil@amd.com