I saw this information on this site and decided to "blog" it so it would be easily available in the future. It is about the turn on time of the diodes and was originally posted about a snubber question.
\(\begin{array}{l|c|c}
Time & 1N4001-5 &1N4006-7
\hline
.2 usec &.1A&
.3 usec &1.5 A& .1 A
.4 usec &4 A &1 A
.5 usec &6.3 A& 2 A
.6 usec &8 A &4 A
.7 usec &10 A &5.4 A
.8 usec & &7 A
.9 usec & &8.4 A
1 usec & &10 A
\end{array}\)
Associated math goes like this: If you want to use a capacitor to help the SCR survive until the diode conducts, IT/V = C
Example for a 1N4007, (4 A x .6 usec)/200V = .012uf minimum. (12 nanofarads)
The 1N4005 can do this in .4 usec. and is rated for a generous 600 volts. (4A x .4 usec)/200V = 8 nanofarads minimum.
Take this into account if the snubber cap calculates to be in the nanofarad range.
\(\begin{array}{l|c|c}
Time & 1N4001-5 &1N4006-7
\hline
.2 usec &.1A&
.3 usec &1.5 A& .1 A
.4 usec &4 A &1 A
.5 usec &6.3 A& 2 A
.6 usec &8 A &4 A
.7 usec &10 A &5.4 A
.8 usec & &7 A
.9 usec & &8.4 A
1 usec & &10 A
\end{array}\)
Associated math goes like this: If you want to use a capacitor to help the SCR survive until the diode conducts, IT/V = C
Example for a 1N4007, (4 A x .6 usec)/200V = .012uf minimum. (12 nanofarads)
The 1N4005 can do this in .4 usec. and is rated for a generous 600 volts. (4A x .4 usec)/200V = 8 nanofarads minimum.
Take this into account if the snubber cap calculates to be in the nanofarad range.