I'd avoid the Chinese soft starts. One I got still allows enough power through to light up all the LEDs inside when 'off'.
I haven't debugged it yet out of disgust for the wasted time.
I haven't debugged it yet out of disgust for the wasted time.
Rod Elliot has a pcb for an active soft start that's probably a well thought out circuit but I won't be using one unless absolutely necessary.
Yep. Kudos to Rob for the bulletproofness of what he puts out into the world. I'd have been better off going that way... I was seduced by convenience and alluring features.
I think I'm still talking about amps. 🙂
I think I'm still talking about amps. 🙂
Yes, I must admit that I've found the 10R thermistors quite adequate for the task but I do use the dc trap for anything bigger than 200va torroidal transformer these days - this, plus the Haggerman snubbers (C, R+C) on the secondaries and a well thought out C-Mx is a pretty good combination.
Some years ago (more than I want to think!) I built a big 250W classAB amp to drive troublesome speakers like the dastardly Infinities, etc - these were the days when large EI transformers were the rule - the damn thing weighed about 40kg - biased about 10W classA, valve gain stage, fan cooled, 10 o/p TO3 trannies/ch - a monster that worked extremely well - I think I'd have a serious hard look at the switchmode supplies these days with the appropriate filters
Some years ago (more than I want to think!) I built a big 250W classAB amp to drive troublesome speakers like the dastardly Infinities, etc - these were the days when large EI transformers were the rule - the damn thing weighed about 40kg - biased about 10W classA, valve gain stage, fan cooled, 10 o/p TO3 trannies/ch - a monster that worked extremely well - I think I'd have a serious hard look at the switchmode supplies these days with the appropriate filters
I use a mains soft start on all transformers from 100VA upwards.
I fuse all my transformers to close rated spec, if the very low value fuses are available.
Take the 100VA on a 240Vac supply. The close rated fuse would be 0.42A. I use a T500mA
Adding a 140r bank of resistors prevents that small fuse from blowing on repeated cold starts.
80VA and lower have a high resistance primary that is in effect a current limiter during start up.
I use an F500mA to fuse these, or smaller.
I fuse all my transformers to close rated spec, if the very low value fuses are available.
Take the 100VA on a 240Vac supply. The close rated fuse would be 0.42A. I use a T500mA
Adding a 140r bank of resistors prevents that small fuse from blowing on repeated cold starts.
80VA and lower have a high resistance primary that is in effect a current limiter during start up.
I use an F500mA to fuse these, or smaller.
I have currently got my eye on this. https://www.ametherm.com/datasheets/ms2220005/
This one seems up to the caveman task.
This one seems up to the caveman task.
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Jeez, what monsters - these make the big Semicron's look small!
Curiously, I was just reading here about using some GaN transistors as diodes and seemingly getting excellent results - just saying, mind you
A few years ago, the guy that started the long-running 'Ultimate NOS 1541A dac' thread (E C DESIGNS) suggested in one of his power supply designs to use 2 diodes in // but one of them has an additional small series resistor thus allowing a 2 step charging pulse function - I was fascinated by the idea but never did try it - must get my finger out ....
I wonder what they use for charging current control at the 'Synchrotron Project' near the Monash Uni?
Curiously, I was just reading here about using some GaN transistors as diodes and seemingly getting excellent results - just saying, mind you
A few years ago, the guy that started the long-running 'Ultimate NOS 1541A dac' thread (E C DESIGNS) suggested in one of his power supply designs to use 2 diodes in // but one of them has an additional small series resistor thus allowing a 2 step charging pulse function - I was fascinated by the idea but never did try it - must get my finger out ....
I wonder what they use for charging current control at the 'Synchrotron Project' near the Monash Uni?
Yeah monsters. Hahaha
Because I have mutiple transformer taps I wanted a rectifier with bolted connections (don't like spades).
I also like the geometry of the connection.
Because I have mutiple transformer taps I wanted a rectifier with bolted connections (don't like spades).
I also like the geometry of the connection.
Thanks! Just curious to read the datasheet and try and work out why them in particular (noted on the screw terminals!).