All,
I own a 3E audio TPA3255 (TPA3255-2CH-260W | 3e Audio) which I sometimes run 53-54V (yes, I know that's high!)
I have noticed that the inductors get too hot to touch (80C+ I guess) when operating in this state.
Is this something to worry about? I have some active cooling to keep heatsink running nice and cool, but not sure if I should worry about forced flow over the inductors now? Would their performance be reduced in this hot state?
Kind regards,
I own a 3E audio TPA3255 (TPA3255-2CH-260W | 3e Audio) which I sometimes run 53-54V (yes, I know that's high!)
I have noticed that the inductors get too hot to touch (80C+ I guess) when operating in this state.
Is this something to worry about? I have some active cooling to keep heatsink running nice and cool, but not sure if I should worry about forced flow over the inductors now? Would their performance be reduced in this hot state?
Kind regards,
You're running too much power through the board. Of course it's running hot. Running hot will shorten the life of the board.
More voltage will mean much more dissipation in the inductors. Once ferrite is getting hot like this it tends to degrade and become more lossy, leading to runaway failure eventually.
If its designed for max supply of 51V do not exceed this, in fact it usually pays to derate a little from a maximum supply - 48V seems a prudent value given the specs.
If its designed for max supply of 51V do not exceed this, in fact it usually pays to derate a little from a maximum supply - 48V seems a prudent value given the specs.
Hi nannoo,
Thanks for the comment, but can you elaborate? Running components hot is a given for shortened lifespans.
- Why would it shorten the lifespan specifically? Would it be the thermal cycling, enamel breakdown, cascaded effects elsewhere..?
- What would the maximum temperatures permissible be? I am reading some Murata inductors are good up to 125C? Does anyone know the part number for these?
- Would saturation be a problem for these specific inductors, and if so - what would the effects be? Would it be meaningful in the 'real world', or would it be measurable but not audible?
- If I were to measure the temperatures, would this give a better steer? I can instrument with thermocouples if needed
- What failures am I likely to see, and how could I observe, control or mitigate them?
Thanks,
Thanks for the comment, but can you elaborate? Running components hot is a given for shortened lifespans.
- Why would it shorten the lifespan specifically? Would it be the thermal cycling, enamel breakdown, cascaded effects elsewhere..?
- What would the maximum temperatures permissible be? I am reading some Murata inductors are good up to 125C? Does anyone know the part number for these?
- Would saturation be a problem for these specific inductors, and if so - what would the effects be? Would it be meaningful in the 'real world', or would it be measurable but not audible?
- If I were to measure the temperatures, would this give a better steer? I can instrument with thermocouples if needed
- What failures am I likely to see, and how could I observe, control or mitigate them?
Thanks,
Honestly most of these questions are beyond the scope of my abilities in electronics, and I may make a mistake in trying to answer others.
My engineering instinct (which is normally reliable) says if you don't know the circuit and didn't design it, running at over voltage will force it to fail. I'm not worried about a coil of wire, I'm worried that the whole circuit is designed to run at lower power.
Why not just run at 48V? (I know a lot of people run these at 36V incidentally).
Some electronics specs are clear and some are nominal, no doubt some parts in the board will cope fine with the voltage but I suspect others will fail relatively soon. What is the scope of voltage inlet for the board? Are you over spec or on limit? I know when I researched this board months ago I plumped for a 48v smps, I can't tell you why.
My engineering instinct (which is normally reliable) says if you don't know the circuit and didn't design it, running at over voltage will force it to fail. I'm not worried about a coil of wire, I'm worried that the whole circuit is designed to run at lower power.
Why not just run at 48V? (I know a lot of people run these at 36V incidentally).
Some electronics specs are clear and some are nominal, no doubt some parts in the board will cope fine with the voltage but I suspect others will fail relatively soon. What is the scope of voltage inlet for the board? Are you over spec or on limit? I know when I researched this board months ago I plumped for a 48v smps, I can't tell you why.
Hi zerokevin99
We are talking about idel mode ... not on full load, right?
Can't see exactly which coils are used, but I have experienced the same problems with the ICE components 1D10A-220M (seems to be similar). Already at a supply of +-40V they start to heat up quite a lot.
I think they have made the trade off btw number of windings and thereby the electrical loss in the wire and therefore chosen a core material with higher loss, and therefore more core loss and heat.
The coil if hot will also heat up the pcb and all the components including the caps ... not ideal.
Change to a T106-2 with a wire of 1 or 1.25mm, they will not heat up the same way.
In my opinion the coil should not be so hot you can´t touch it, in idle.
You will need a good margin for the temperature rise going from idle to full load.
KR Baldin
We are talking about idel mode ... not on full load, right?
Can't see exactly which coils are used, but I have experienced the same problems with the ICE components 1D10A-220M (seems to be similar). Already at a supply of +-40V they start to heat up quite a lot.
I think they have made the trade off btw number of windings and thereby the electrical loss in the wire and therefore chosen a core material with higher loss, and therefore more core loss and heat.
The coil if hot will also heat up the pcb and all the components including the caps ... not ideal.
Change to a T106-2 with a wire of 1 or 1.25mm, they will not heat up the same way.
In my opinion the coil should not be so hot you can´t touch it, in idle.
You will need a good margin for the temperature rise going from idle to full load.
KR Baldin