Coil replacement TO COIL 330UH IN THE pathway regulator 7809 ?

[dazzz]

I need help on the part chosen for the SMPS mode of Danon 2900
One of the components I replaced this coil L909
Its value 4.7UH
His model is LHL08TB4R7M

Inductance- 4.7UH

Current Rating-3A

DC Resistance- 0.025

Frequency - Self Resonan- 30MHZ

Q @ Freq - 40 @ 7.96MHz


I bought this coil PANASONIC - ELC-10D Series 330UH


nductance-330UH

DC Resistance Max-0.32ohm

RMS Current (Irms) - 900mA

DC CURRENT RATING-0.9A

Test Frequency-10KHZ


Can I use a coil that I bought
I worry only because the current value ?

 

[KatieandDad]

From the small bit of the circuit that you have shown, it appears to be too low a current. The voltage there is DC so the coil is only there to reduce HF noise. Be careful of its DC resistance though as there could be up to 3A flowing, 1A each through the 3 x regulators that can be seen.

Personally I would get a coil that can handle at least 3A, not 0.9A, as the regulators have heatsinks they might be passing more than 0.9A in total.

 

[dazzz]

From the small bit of the circuit that you have shown, it appears to be too low a current. The voltage there is DC so the coil is only there to reduce HF noise. Be careful of its DC resistance though as there could be up to 3A flowing, 1A each through the 3 x regulators that can be seen.

Personally I would get a coil that can handle at least 3A, not 0.9A, as the regulators have heatsinks they might be passing more than 0.9A in total.

Thanks
This is what I thought to

 

[FoMoCo]

There could be up to 3A flowing, but most likely not. You can always measure the current flowing. If it's under, say, 500mA, go for it. Or you can play it safe and get an inductor with a higher current rating. (My personal choice.) The inductance value would not be critical.

 

[dazzz]

There could be up to 3A flowing, but most likely not. You can always measure the current flowing. If it's under, say, 500mA, go for it. Or you can play it safe and get an inductor with a higher current rating. (My personal choice.) The inductance value would not be critical.

My problem is to find coil 330UH
That the diameter is not too large
( In the Area I replaced the coil dnot have much room )
3 amps I've seen in FARRNEL
Starting diameter 25 mm

 

[KatieandDad]

It's probably not doing much anyway, try a shorting link in place of the inductor.

 

[dazzz]

It's probably not doing much anyway, try a shorting link in place of the inductor.

I have a reason I replaced the coil
I do a comprehensive project on power supply
The DENON DVD 2900
And increasing the value of this coil give me better nois filtering to reg 7809
7909
9 volt
If I replace the coil in this with shorting link I did not do anything

 

[KatieandDad]

True, but you can't find a coil to fit.

You could try an axial coil and mount it vertically.

 

[KatieandDad]

This one might fit.

Buy Leaded Inductors Inductor radial ELC09D 4.7uH Panasonic ELC09D4R7F online from RS for next day delivery.

 

[dazzz]

True, but you can't find a coil to fit.

You could try an axial coil and mount it vertically.

I might have a solution
Buy Coil 330UH 4.5A
FROM FARNELL

MURATA POWER SOLUTIONS
INDUCTOR, 330UH, 4.5A




And mount it in the bottom of the SMPS
What do you think ?

 

[FoMoCo]

My problem is to find coil 330UH
That the diameter is not too large
( In the Area I replaced the coil dnot have much room )
3 amps I've seen in FARRNEL
Starting diameter 25 mm

Why do you need 330uH? The schematic shows 4.7uH.

 

[dazzz]

Why do you need 330uH? The schematic shows 4.7uH.

To have better noise filtering to audio circuit regulators

This coil is only part of the swap
I replaced the main filter capacitors from 47UF 400
To RUBYCON 220UF 400V
Diodes of the bridge diodes were replaced by diodes
VISHAY SEMICONDUCTOR - VS-ETX0806FP-M3 - DIODE, HFAST soft recovery 600V, 8A, TO220FP
Regulators filter capacitors
OF
7909
7809
I uploaded the value from 220UF 16V
To RUBAYCON ZLH 470UF 35V

I replaced most of the capacitors in SMPS
To RUBAYCON ZLH
It's just part of the improvements on the device
I also made a lot of improvements in audio circuit


Probably later I'm going to build a power supply to the circuit audio based on Toroaidl transformer
Provide voltage
9 +
9 -

 

[FoMoCo]

To have better noise filtering to audio circuit regulators

It'll never make a difference... Especially when you increase the parasitic capacitance and allow more noise...

 

[dmills]

Yep, LC filters have to be designed bearing in mind that the L (in particular) is not anything like an ideal component, just making it bigger while lowering the SRF is not likely to have the desired effect.

Spice is your friend for investigating this sort of thing, doing it on paper when you include all the parasitics is an excersize in linear algebra not for the faint hearted.

Regards, Dan.

 

[dazzz]

this is the denon dvd 2900 smps schematics