On 1 Jul 2005 at 16:18, Olin Lathrop wrote:
The load current limit is directly
> proportional to a transistor gain.  Since the maximum transistor gain is
> usually not specified, there is no upper bound on the load current.  In
> other words, there is no current limiting.  Even if the maximum gain is
> specified, there will be a large variation between min and max transistor
> gain.  Ratios of 5-10 are easily possible.  This is not what I would call
> "predictable" in the current context.

Why are you focusing on current limit? My circuit is not intended to limit 
current. The feature I was touting is fairly constant driver(not output) 
current through power supply voltage change when Vmotor >= Vlogic. 
With the two input resistors, Vmotor < Vlogic is also permitted, and 
driver current decreases as Vmotor decreases below Vlogic.

I think the issue here is that you misread my initial description and 
thought I was talking about current limit, which I was not.

Cheerful regards,

Bob

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