From: Fred Bloggs
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Subject: Re: How to get CMOS counter to drive a relay?
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Date: Thu, 17 Oct 2002 14:12:43 GMT
NNTP-Posting-Date: Thu, 17 Oct 2002 07:12:43 PDT
Organization: EarthLink Inc. -- http://www.EarthLink.net
> Fred Bloggs wrote:
>>John Fields wrote:
>>>That 360µA output at 125°C is _worst case_ from -55 to 125C, so the
>>>chip will _always_ be able to source more than that from -40 to 85C.
>>>Try reading a spec sheet before you start spouting false
>>>pronouncements. You're right about the the margin, but for greater
>>>detail I usually get paid.
>>Your reasoning is naive. It appears that you know nothing about parts
>>cost, avoiding dependence on a single high-beta part, relay coil
>>parameter change with temperature, age, and manufacturing tolerance,
>>variation of component parameters across manufacturers and time, and
>>testing limits on "guaranteed" performance parameters and implications
>>for your QC. As for paying you, no thanks, I would rather flip a coin. I
>>would consider paying you to work for the competition however;-)
> You are way out of line, here.
> And you missed the point with your original post.
> The OP asked:
> "What's the SIMPLEST method to get a Fairchild CD4020/40/60
> counter to drive a relay with one of its Qx outputs?"
> (Emphasis mine)
> The SIMPLEST is NOT a 2 transistor circuit.
You're right, the simplest way may be to use parallel spare CMOS buffers.