Hello !
I posted this question in an earlier thread but I try again.
it is normal for the coil in the Zen lite to get hot. I measured the temperature to + 80 C after 30 minutes. I installed a cooling fan and the temperature dropped to 60 C.
I could not get a 14 gauge 4mH (1.63 mm) coil in Sweden. My coil is made by 1.4 mm wire. Is the high temperature normal or not ?
The caps are slightly lower 20000 uF instead of 25000 uF. (the Circuit och powersource) Does this generate heat in the coil ?
Dan P
I posted this question in an earlier thread but I try again.
it is normal for the coil in the Zen lite to get hot. I measured the temperature to + 80 C after 30 minutes. I installed a cooling fan and the temperature dropped to 60 C.
I could not get a 14 gauge 4mH (1.63 mm) coil in Sweden. My coil is made by 1.4 mm wire. Is the high temperature normal or not ?
The caps are slightly lower 20000 uF instead of 25000 uF. (the Circuit och powersource) Does this generate heat in the coil ?
Dan P
The temperature is loss of power as some of the power is now heat. Try using double wound 0.8mm or even larger but I think the loss could be in any core used due to eddy currents
Hi, Dan,
An air core 4mH coil made of 1.4mm wire should be good up to about 2.5A DC Iq, you can use 4 units in serial parallel combination to help heat distribution, but I think we need more info than that to be able to help you further, there could be something else wrong that causes excessive dissipation.
- DC Iq passing through your coil and DC resistance of your coil
- exact circuit you use, zen lite have many variations
- whether your coil suitable for DC - how your coil is made - air core, gapped EI iron core or...
- Pictures should help
Hello !
I just measured my Zen Lite when I uppdated to bigger internal fans.
The current through the Coil is 5.1 A
Internal resistance measured to 2,3 Ohm
DC meassured 4.2 Volt
The variations I buildt was the balanced version (FIG 16) zen Lite.
4 bulbs 300 W
Toroid specs 800 VA 2x53 Volts
The coil is an air coil with 1.4 mm Cu.
Rdc 066.
I hope this helps to sort out the heat problem.
best regards
Dan P
I just measured my Zen Lite when I uppdated to bigger internal fans.
The current through the Coil is 5.1 A
Internal resistance measured to 2,3 Ohm
DC meassured 4.2 Volt
The variations I buildt was the balanced version (FIG 16) zen Lite.
4 bulbs 300 W
Toroid specs 800 VA 2x53 Volts
The coil is an air coil with 1.4 mm Cu.
Rdc 066.
I hope this helps to sort out the heat problem.
best regards
Dan P
Attachments
The measured value is 2,3 Ohm over the coil with my multimeter.
0.66 is taken from the homepage were I bought the coil.
Best regards Dan P
0.66 is taken from the homepage were I bought the coil.
Best regards Dan P
Ok Dan, but your meter has problem, invalid reading, the number does not add up.
However, as I stated previously, 1.4mm is good up to 2.5A, for 5.1A you need at least 2 in parallel. But now you have 2mH instead of 4mH. Try it first, if you don't like it, you can add 2 more in parallel in series to the first 2 to get 4mH back.
However, as I stated previously, 1.4mm is good up to 2.5A, for 5.1A you need at least 2 in parallel. But now you have 2mH instead of 4mH. Try it first, if you don't like it, you can add 2 more in parallel in series to the first 2 to get 4mH back.
You may want to just build a Mosfet cap multiplier. You would just lose about 4.5v in the regulator. lower your ripple more and might even be cheaper.
Yes, it gets very hot.
5.1Adc through 2r3 is 59.8W !!!!!! in the coil.
For wire in an airstream with normal electrical insulation you can use 3.1A per sqmm.
1.63mm diameter has a current rating of ~6.5A when cooled by the air stream.
1.4mm diameter has a current rating of ~4.8A when cooled by the air stream.
Your "coil" will have many turns insulating each other from the cooling air stream
The acceptable current rating will be much lower than 3.1A per sqmm. Maybe less than half that value.
A good clue is the resistance of the coil and Vdrop.
0r1 will dissipate ~2.6W
0r5 will dissipate ~13W
1r0 will dissipate ~26W
But, that 1r0 will drop 5.1V. Can your circuit perform properly with a 5.1V loss between the supply and the circuit?
2r3 will drop ~11.7V !!!!!
P=IV = 5.1*11.7
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Zen Lite Uppdate
Today I finally mounted the new coils for my Zen Lite. The problem with the heat from the coil seems to be solved. As Indra1 suggested I used two coils parallel. I bought two Mundorf L100 coils 8.2 mH.
The coils still get warm but now the temperature is about +50 C.
I also took the opportunity to increase the value of some capacitors.
I use small fans to cool the amplifier due to the construction. The chassis with heat sinks is a bit too small so it feels like a good idea to use fans.
I took some pictures of the amplifier. Preamplifier is seen under the small Sonos box
Thanks for all the help.
Today I finally mounted the new coils for my Zen Lite. The problem with the heat from the coil seems to be solved. As Indra1 suggested I used two coils parallel. I bought two Mundorf L100 coils 8.2 mH.
The coils still get warm but now the temperature is about +50 C.
I also took the opportunity to increase the value of some capacitors.
I use small fans to cool the amplifier due to the construction. The chassis with heat sinks is a bit too small so it feels like a good idea to use fans.
I took some pictures of the amplifier. Preamplifier is seen under the small Sonos box
Thanks for all the help.
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