Which IRS2092 modules?

[Cristi]

please try again after restart browser or use internet explorer. there are some cookie issues with chorme, mozilla and firefox. if still cannot I will send you the invoice.

[noah katz]

Ah yes, I was using Firefox.

IE worked fine, payment sent

[Cristi]

Got it. thank you. I will send you mail as soon as the power supply is done, tested and ready to ship.

[noah katz]

In the mean time I can continue to work on the case layout.

Originally Posted by Cristi

The new SMPS board will be 100x150mm, will fit into a 1RU case, and I will give the exact size next week. The connectors will be places at the extremities of the board, for shortest routing path to amplifier modules.

Are the AC in and DC in roughly the same locations as on the SMPS800R?

Also, if they have IEC connectors for AC input like SMPS, could I get instead screw terminal blocks?

Thanks

[noah katz]

Cristi,

I want to put level control pots on the inputs to the CxD300 surround amps.

What value should they be?

And how's it going on the new SMPS?

Thanks

[CharlieLaub]

Hi Cristi,

I have a linear unregulated power supply with +/-89V rails and need an amp for it. I'm thinking of one of these (the 600W version):
Connexelectronic

In another thread, you mentioned that IRS2092 modules could go up to 94VDC and be OK.

I am concerned about bus pumping - these will be used for subwoofers. I will be using 8 ohms nominal loads. Let's say I use large caps (100,000 uF or more total) and CRC filtering to reduce rail ripple. Will this reduce concerns about bus pumping?

-Charlie

[Cristi]

Dear fellows, I couldn't access the forum for more than one week. some major event will take part over here this week and next week and I thing it has to do with connection problems.
The position of mains and output connectors will be approximately the same as the SMPS800R(E) and no IEC connector this time.
Potentiometers for CxD300 must be 5-10K because the low input impedance, and I strongly suggest to drive these modules from a low-impendance source.
By the end of the week I will send you some preview.

[Cristi]

Charlie, +-89V might be working but if you gonna use it for subwoofer, the OVP might mute the module earlier. of course it can be increased to +-95 to +-98V or so, but you're close to the maximum working voltage of output transistors and is not reliable for long term use.
adding such a large capacitance might affect the power supply, either smps or mains transformer. 100mF at 100V are huge. no need to use such large caps, even to avoid pumping. up to 10mF would be enough. the main issue is not only the bus pumping when supply a class D module with such high voltage, but the fact that is very possible that durring nightime the mains voltage to increase few V so does the DC voltage on the amplifier supply, and will render the amp unusable.

[noah katz]

Thanks, Cristi

[CharlieLaub]

Originally Posted by Cristi

Charlie, +-89V might be working but if you gonna use it for subwoofer, the OVP might mute the module earlier. of course it can be increased to +-95 to +-98V or so, but you're close to the maximum working voltage of output transistors and is not reliable for long term use.
adding such a large capacitance might affect the power supply, either smps or mains transformer. 100mF at 100V are huge. no need to use such large caps, even to avoid pumping. up to 10mF would be enough. the main issue is not only the bus pumping when supply a class D module with such high voltage, but the fact that is very possible that durring nightime the mains voltage to increase few V so does the DC voltage on the amplifier supply, and will render the amp unusable.

Cristi, Thanks for your comments and thoughts above. It is good to keep these things in mind. I am following up, below:

I measured my line voltage. It's a bit high for the USA, at 122VAC and doesn't seem to vary much day-to-day, at night, etc. I used the measured AC voltage to calculate the transformer secondary voltage I will get, then accounted for losses and rectification and was conservative in arriving at the 89VAC figure. But I will double check these values.

I disagree on the size of the caps. 10,000uF (per rail, meaning 5000uF in series across the full +/- supply) is IMHO way too small because the caps will have too little ability to deliver power or adsorb power, ripple will be very high and regulation low. I plan to use a linear power supply (not smps) and when the amp is delivering power at frequencies less than twice the line frequency the effective rectification factor in the AC-to-DC conversion goes down by 10-15% and you need to rely more on the caps to supply instantaneous power. Maybe 100,000uF per rail is overkill, however...

How do I request from you modules with the higher OVP limit and rail voltage range when ordering? I assume that this requires changing caps and resistors for higher the voltage level and increased dissipation...

I want to mount the modules on a larger heatsink than what is provided. I do not want to use a fan. Looking at the pair that I already have in hand (the 400W version) it looks like I can remove the heat sink from the assembled modules and re-install it on a new heatsink without desoldering anything. Is that correct?

-Charlie