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Subject: Re: zero-power toggle circuit; was, how to master electronics
References: <email@example.com> <firstname.lastname@example.org> <3DD39D90.email@example.com>
Date: Fri, 15 Nov 2002 12:05:59 GMT
NNTP-Posting-Date: Fri, 15 Nov 2002 07:05:59 EST
Organization: Road Runner
Winfield Hill wrote:
> Terry wrote...
>>Winfield Hill wrote:
>>>>Thanks for all the comments. Here's wafer's new circuit:
>>>: ,--------+----(O) V+
>>>: | |
>>>: R4 |
>>>: 100k |
>>>: | |
>>>: +----||--+ Q2
>>>: | ||>-'
>>>: ,-----------------------+ |--,
>>>: | R2 | |
>>>: R1 ,-- 220k --- | -------+--+---(o)
>>>: 1M5 S1 | | | |
>>>: | _|_ | |--' _|_ |
>>>: +---o o----+ ||<-, Q1 /_\ LOAD
>>>: | +--------||--+ 2N7000 | |
>>>: | 0.1uF | | | |
>>>: === C1 R3 '--------+--+---(O)
>>>: | 100k |
>>>: gnd | gnd
>>Win, Jonathan: I'm struggling to understand why I can't get it to
>>simulate. I don't have a BSS110, but tried several alternatives
>>for Q2. Can you positively confirm the circuit's OK please?
> It's OK. Were you careful to connect source of the Q2 p-channel
> FET to the + rail and the source of Q1 n-channel FET to ground?
> I dunno, just a stab in the dark as to what you're doing wrong.
> Are you activating the switch for just a short time, 1/4 second?
>>I downloaded the BS110 Fairchild data sheet which says "They can
>>be used, with a minimum of effort, in most applications requiring
>>up to 0.17A DC". I thought we were talking power switches?
> Hey that wimpy part was Wafer's selection. You can try something
> more serious like an IRF9540, or IRF9Z34N. Or maybe an FB-class
> FET, a real man's part in a SOT-227 bolt-it-in 500W package. :)
> - Win
One advantage to my design is that the user can hold down the switch
indefinitely with no side effects :) Please be sure to see my new post
using the ASCII art, but INCLUDING my original comments and explanations.