[GreenKeys] To snub or not to snub?

[WA5CAB at cs.com]

And the fourth scheme is to replace the fragile transistor with a 25K 25W EMP 
and spike proof rheostat.  And never have to worry about it again.  First 
rule of fail-safe design - never use an active component when a passive one will 
serve, work as well, and produce no more heat.

In a message dated 4/9/2007 10:00:34 PM Central Standard Time, 
jhhaynes at earthlink.net writes: 
> You have to snub to protect the transistor.
> 
> One scheme is an R-C series circuit, where you choose the R and C
> so that it snubs adequately and dissipates the energy in the resistor.
> 
> Another scheme is to run the R-C series circuit from colletor to
> base of the switching transistor, so the inductive spike keeps the
> transistor conducting until it dies out.
> 
> And another scheme is to use a Zener diode or a MOV device to
> absorb the transient.
> 

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