Low resistance coil or large pulse width?

[1843]

Hi everybody,
Which one is better for applying a high current ( 3-4A ) in a coil ?(about energy dissipation)
1. lowering the coil resistance.
2. Increasing pulse width ( to 1mS ).

Best regards

[Max]

Hi everybody,
Which one is better for applying a high current ( 3-4A ) in a coil ?(about energy dissipation)
1. lowering the coil resistance.
2. Increasing pulse width ( to 1mS ).

Best regards

Hi everybody,
Which one is better for applying a high current ( 3-4A ) in a coil ?(about energy dissipation)
1. lowering the coil resistance.
2. Increasing pulse width ( to 1mS ).
Best regards

Hi,
if you have a longer tx pulse you have also much more power drain cause you need more power to give the current rise (NOT at parity of inductance but) at current end peak parity...it's not a good idea. Also you have more power dissipation on switching device(s)...and that's another bad idea too...you could end-up with burn devices or thermal drifts or other kind of bad influence to the overall stability (think e.g. at transients magnitude on power rail also with big tank capacitors...)

What's important is the peak current you have just before switchoff occourrs and not the charging rate...so faster rate with equal end-peak is better cause you save energy that otherwise you lose without any advantage.

So the best thing is to have a good peak current with the smaller tx pulse width. This way you get same performance of another coil/pulse-lenght but save much of the energy. Offcourse it's not always easy to figure out how to save energy and having good performances too.

Also inductance plays a major role here...cause charge or the inductor depends on it and other parameters too (e.g. coil resistance and other resistances like RDSon...limiting resistors etc)...you need to keep inductance small to avoid excess of ringing and to keep dumping resistor small... but not too much few inductance...and also capacitance is another issue.

At the end you need a good compromise to get good perfomances at a reasonable power dissipation.

Best regards,
Max

[1843]

Many thanks for your good and complete answer.