Ubergeek63
Well-Known Member
While it is built in to the UNL series it is also a junk silicon diode not meant for switcher frequencies, hence I still say that if you insist on using them that way add good schottkys instead of relying on the slow ULN silicon.I see your point. I hadn't thought about EMI problems that would be exacerbated by having the diode located far from the inductive load, so I now understand the need for mounting it close. In the case where there are long wires between the switch and the inductive load, a diode near the switch (built into the ULN series, but not into most other devices) is also desirable.
Dan