Darren Gibbs wrote:
> On May 26, 2006, at 7:15 AM, Sergey Dryga wrote:
>   
>> Darren,
>> I would use a MOSFET to drive a solenoid, bipolar transistors  
>> require to much
>> current to drive them.  There is a lot of logic MOSFETs that will  
>> do the job,
>> e.g. NTE2980
>>     
>
> I'll try a MOSFET and see what happens.  I'm really curious though to  
> understand why I'm getting this locking on behavior.  From what I've  
> read so far about transistors it doesn't make sense.  The circuit  
> couldn't be simpler AFAICT.
>
> thanks,
>
> darren
>   
That is the right thing to do. There is little protection internally, so 
be sure to use a TVS or similar protection
from spikes. This will eliminate the heat that rapidly destroyed the TIP120.

--Bob
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