Hi Wayne,

In general I'd say yes, you need a snubber. But if the load on the
secondary captures the flyback, that will prevent the transistor from
overvoltaging and you may not need any further snubbing.

But I have a question about the way you are driving the PNP transistor.
Does the PIC first drive an NPN transistor and then the PNP? Because the
PIC can't fully turn off a high side PNP by itself if the PNP is
controlling a voltage higher than the PIC's V+.

Cheerful regards, Bob

On Sat, Oct 24, 2015, at 10:30 AM, Wayne wrote:
> Hi all,
>=20
> Apologises for possibly hijacking the original snubber diode thread, but
> does the same ideas apply to transformers?=20
>=20
> I have a pic driven high side php driving a small transformer from 9v to
> provide output pulses, however from time to time the driver php gets hot
> enough to melt the solder connection and drops off the board but I cannot
> seem to replicate this on the bench. Do I need a snubber diode??
>=20
>  would the generated voltage spike generate a pulse in the output of the
>  transfer?
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> Thoughts?
>=20
> Wayne

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