Mail Archives: geda-user/2012/03/16/12:26:46

X-Authentication-Warning: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113;
MIME-Version: 1.0
In-Reply-To: <>
References: <CALSZ9gp3RUu2WiEU9SoJROD+3LQcF3XR4YKJiKP1P-U2OWM4-Q AT mail DOT gmail DOT com>
<20120316142719 DOT 26210 DOT qmail AT stuge DOT se>
<4F63506D DOT 90602 AT keensupport DOT net>
<4F6354C2 DOT 10502 AT keensupport DOT net>
<20120316150615 DOT 29273 DOT qmail AT stuge DOT se>
<CALSZ9gqfcTrcYuDunFqrz_cEgbSCB6qxyz-eE3YhGHeu7NoC7Q AT mail DOT gmail DOT com>
Date: Fri, 16 Mar 2012 12:26:15 -0400
Message-ID: <>
Subject: Re: [geda-user] Daughter's Science Fair
From: Bob Paddock <graceindustries AT gmail DOT com>
To: geda-user AT delorie DOT com
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

On Fri, Mar 16, 2012 at 11:33 AM, Rob Butts <r DOT butts2 AT gmail DOT com> wrote:
> So if I use a 1 watt 15k ohm resistor in series with the nail and an ac
> outlet that will give me 8ma alternating current and that should light the
> bulb?

With no isolation transformer this is not a safe approach for
something in a Science Fair.
Anything connected to the AC Line always presents a electrocution
hazard when not isolated.
Currents of less than 8 mA across the heart could kill.

Two identical transformers hooked up back-to-back will get you safety isolation.

For example in the past 110 in 6.3V out transformers were common.
Hooking the two 6.3V sides together would get you isolated 110VAC out.

- Raw text -

  webmaster     delorie software   privacy  
  Copyright 2019   by DJ Delorie     Updated Jul 2019