On 12.12.15 21:32, Gene Heskett wrote: > But I suspect that 90 volts (cap input filter) is still way too much for > those coils over any time period in excess of 2 or 3 minutes. > > So, how much more do I need to reduce the coil voltage in order to run > them at a reasonable temperature on DC? > > I have some other toroid trannies that might be more suited for this as I > suspect the operation from DC can probably be reliably done with 30 > volts w/o baking the coils. > > Does anyone else have similar experience who can toss a few words my way > on this?
They might hold on 30v, but I don't see them pulling in on it. If the relay is switched well after power-up, then a resistor feed of DC to a middle-sized electrolytic briefly provides full pull-in voltage via whatever switches the coil current, and the resistor is scaled for coolness, according to taste. (Well, finger-burn, actually.) Now, to "unsimplicate", if that is the builder's bent, there are gadgets like: http://www.ti.com/lit/ds/symlink/drv120.pdf , located by a quick google for "pwm solenoid relay driver". There are doubtless other ways to cook this cat, variously attractive, depending on ingredients to hand. Erik ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
