MY DESIGN L20D IRS2092+IRFI4020H 200W8R

[mravlca]

Originally Posted by clm811

Since I will be using a power supply of approx +/-72vdc to +/-75vdc, I will be replacing the 2W resistors with 5W ones; additionally, the stock heat sink will be replaced with 76 x 50 x 22.2mm one, with a 5mm thick baseplate. I expect the devices to run noticeably cooler than stock. My speakers are 4 ohms.

The amps will look like this:

Good thinking! On the first picture you can see temperature ratings of mine L25D runing on +/-72V, stock resistors, speakers are 8ohm. I will replace these resistors with 5W vertical ones.

[clm811]

I started thinking about those sand cast resistors and remembered they are not non-inductive and so they probably aren't the best choice for this circuit.

I will be using Mills MRA5 5W non-inductive resistors instead, with the same larger heatsink as above.

Here is the board with Mills resistors:

[luka]

Originally Posted by clm811

I started thinking about those sand cast resistors and remembered they are not non-inductive and so they probably aren't the best choice for this circuit.

I will be using Mills MRA5 5W non-inductive resistors instead, with the same larger heatsink as above.

Here is the board with Mills resistors:

they can be inductive, they don't conduct any high currents, they just drop DC voltage at low currents

[jlester87]

Does this have a built in over current protection? Anyone tried shorting speaker outputs?(either intentionally or accidentally)

[ljm_ljm]

Originally Posted by vakkuj

Hi,

Finally i have got these from Taobao store through my friend, assembled all the parts.
Attached is the photo of the items i have purchased.

Could someone please give me wiring instructions to do with the attached boards. My Speaker is a 6 Ohm speaker. Should i make any changes ?

And what should be the transformer ratings, how many core ?

1. For Amp. Is it 22 - 0 - 22 Volt , How much should be current rating ?

2. Delay board + Protection board - Voltage ?

3. Mini Preamp What should be voltage ?

Thank you...


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L20D or L25D will need to DC +-60 V DC voltage. In front can get the wiring diagram.

About your voltage AC22-0-22, indeed. TA2022 may be more appropriate it. It's very simple.

[ljm_ljm]

Originally Posted by mravlca

Good thinking! On the first picture you can see temperature ratings of mine L25D runing on +/-72V, stock resistors, speakers are 8ohm. I will replace these resistors with 5W vertical ones.

B: yes. We do not need to change L20D or L25D above capacitors. Because they are very good.

But, radiator and inductance do have some high temperature.

Including IRAUDAMP7S-200. Maybe a small fan can make them work better.

A resistor of about 1.5 watt power above. And equipped with the resistor of power consumption for 3 watt.

So we do not need to change resistance. Although it is very hot. But can't existence problem.

[ljm_ljm]

About link chart

[Bernie7]

Just finished building my first L25D with Connex 500w smps +-72V. It runs much hotter than my L20D amp with the same smps. Mains power consumption at no signal idle is 24w (both channels) compared with 14w for L20D.

Is this due to the extra power mosfet employed or is something amiss with my L25D? Ebay listing for L25D indicates power consumption at 7wpc idle. Can anyone check?

[Hadighorbani]

Originally Posted by nigelwright7557

So long as the switching frequency isnt too high and the deadtime is correct they shouldnt run hot. Obviously the heatsink comes into the equation too.

I run an irs2092 into 2 ohms at 750watts without any trouble.

HI sir
please share your application note, PCB and shematic in site
thanks

[eric914]

Remember that these amps peak efficiency is @ full rated power. Efficiency drops off as power output goes down and below roughly 20w drops off rapidly. An L25D running at the same power output as an L20D would be less efficient and have to dissipate more heat.