Re: Logic Level MOSFET
- From: Fred Bloggs <nospam@xxxxxxxxxx>
- Date: Fri, 16 Nov 2007 06:48:47 -0500
John Larkin wrote:
On Thu, 15 Nov 2007 07:45:18 -0500, Fred Bloggs <nospam@xxxxxxxxxx>
wrote:
John Larkin (uglionical engineer) wrote:
One trick is to add a resistor in parallel with the fet, to keep the
filament warm all the time, to reduce the turnon surge. Cute, but you
really don't need that here.
Mmmmmmmmmmnah...not done that way:
http://www.onsemi.com/pub/Collateral/AN1542-D.PDF (fig 6) or for a very simplified approach on light loads (pun intended) US6518713....
If I correctly interpret your "not done that way" as "nobody does
this", you're just flat wrong. It's been done for decades, in
thousands of applications.
Not interested in the old and inferior way of doing it...
If one must use incandescants, and inrush is a problem, PWM would be a
simpler solution than all that stuff in the ancient Motorola appnote.
It is no solution at all. PWM through a substantial length of wiring harness, with unlimited dV/dt, the one size fits all "solution"? Forget it.
The patent is absurd. Why not just taper the PWM drive and be done
with it?
Things are more bulb-centric these days...too complicated for you?
.
- Follow-Ups:
- Re: Logic Level MOSFET
- From: John Larkin
- Re: Logic Level MOSFET
- References:
- Logic Level MOSFET
- From: James Fraser
- Re: Logic Level MOSFET
- From: John Larkin
- Re: Logic Level MOSFET
- From: Fred Bloggs
- Re: Logic Level MOSFET
- From: John Larkin
- Logic Level MOSFET
- Prev by Date: Re: Light bulb power control/dimmer
- Next by Date: Re: OT: winter's here. First sub-zero temp since summer
- Previous by thread: Re: Logic Level MOSFET
- Next by thread: Re: Logic Level MOSFET
- Index(es):
Relevant Pages
|
