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: Tony Williams
Subject: Re: zero-power toggle circuit; was, how to master electronics
Date: Fri, 22 Nov 2002 12:15:20 +0000 (GMT)
References: <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org>
NNTP-Posting-Date: Fri, 22 Nov 2002 12:18:35 +0000 (UTC)
User-Agent: Pluto/1.14i (RISC-OS/3.60)
In article ,
Terry Pinnell wrote:
> This looks good! I simulated it with CircuitMaker using Tony's
> original component values. It worked fine from Vcc = 5 to 16 V with 22
> of the 32 MOSFET types I tested:
[snip exhaustive list]
Thank you Terry for all the work you have put in.
> I haven't investigated the reason(s) for the 10 failing to toggle.
Probable MOSFET fail reasons could be;
a) Total Fail; Model is wrong.
b) Ok at 16V, fail at low Vcc;
Not enough Vg-s available for that MOSFET at that current.
> Results are shown at
Thank you again.
If you have the time, keep trying to break it. Suggest;
a) Switch bounce. Use a narrow pulse (<1mS?), and increase
the repetition-rate until it fails to toggle properly.
b) On power-on it should always come up in the Off-state.
Because it is a simulation of the npn/pnp bistable,
(using a 4066 to simulate all-off "RTL" gates), then slow
power-on should be no problem.
The 100pF? on TG1's gate is there to try and ensure an
Off-state for fast power-on's (and to keep the last
toggled state, even during noise on the power suppy).
PS; There is a comp I'd like to add. A small diode,
pointing upwards from the top of C1 to Vcc. This is
to help protect the gate of TG1 (from the energy in C1)
during a fast power down.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup