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John-Del[_2_] John-Del[_2_] is offline
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Default mosfet replacement for tip120?

On Wednesday, September 13, 2017 at 8:29:21 PM UTC-4, Jeff Liebermann wrote:
On Wed, 13 Sep 2017 08:33:57 -0700 (PDT), wrote:

im working on a arcade game board . the tip 120 for an eject soleniod is driven right off the processor leg, no pre -driver transistor. didnt even think that was possible, maybe that why it blew. is there a mosfet i can replace the tip120 with?
thanks


I don't like using darlingtons for power drivers. A momentary shorted
load, and the darlington blows up from too much current. This article
should provide some detail:
http://www.sensitiveresearch.com/elec/DoNotTIP/index.html
I can't offer any specific recommendations without some clue as to the
processor output voltage and current capabilities, the solenoid specs,
and the operating voltage.


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Jeff Liebermann

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I wouldn't worry about using a Darlington as a coil driver. Arcade games are generally quite robust (the monitors generally the weakest point) and they've been using them for years with no issues. They used to use relays or even high current leaf switches to drive coils but relays and switches have a finite life.