Re: programmable circuit breaker

On 3/5/2025 9:22 AM, Liz Tuddenham wrote:

Put a resistor in series with the clamp diode, the value can be chosen
to keep the inductive spike just below the maximum allowable voltage and
that will give the fastest turn-off.  By using higher voltage switching
transistors you can have a higher voltage spike and a faster turn-off -
but there is the risk that the spike might be capacitively coupled to
somewhere vulnerable to damage.

It's best to put a zener rated for the coil voltage.  This helps
the coil release faster.  A regular diode will slow the opening of
the contacts.
Relays 101