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Switched Mode Power Supplies (SMPS)

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please contact me by mail or PM for orders information and tracking numbers. i want this thread to be dedicated only to technical discussions.
also, when sending a mail or PM please consider the time shift and the fact that i do not have access to internet all the time, and it might take 24h or more to answer to some mails.
thank you for understanding.

PM sent. Waiting for news.
 
Hi Cristi,
I'm searching for a power supply for my current project (300-350W rms stereo class D amp with IRS2092)
In my view the SMPS800R with +-60V would be a good choice.
Which power supply do you recommend?

Is there also a schematic of this one available, because I want to increase the soft-start time, this should limit the inrush current of the bypass caps (10mF) at start.

Thanks
 
Hi Cristi,

I need an SMPS for an EVM Board from TI (TAS5518-5152K8 Evaluation Module PurePath) and they need "Very stable" power supply because (for example) 100mV change in supply voltage can cause up to 10% THD. The reason is they are Open Loop designs. Any experience with TI PurePath Class D and your SMPS products?

best regards
Alan
 
Hardadi, i just sent you the number by mail.

Alan,
some years ago i have made an amp with TAS5261 + TPA2001D2. the output power was high, compact design and only one supply voltage was needed since i made the 12V with an on-board buck converter. the only things which i did not like was the THD which was strongly load and supply voltage dependent. at that time i used some linear power supply for test. later on, i tested with SMPS500RS and has proved to be much better, but i abandoned the design in the meantime :)
 

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Hi, I have a question regarding the maximum output-side capacitance.

I'll be powering a 41Hz Amp4 with a SMPS500R-Single. This TK2050 amplifier kit has 20.000µF capacitors included on the board [link]

Should I avoid putting them in? Change to a smaller capacitance? Or just put them in? :)

I repeat my question: What capacitance is allowed on the output of the SMPS500R-Single? Thanks!
 
kristleifur: the maximum capacitance value depends on the start-up time and output voltage and it decrease exponentially while the output voltage increase. for SMPS500RS-24V a total capacitance of 22mF is not a problem, and the maximum should not exceed 68mF. for 30-36V version, the capacitance should not exceed 33mF and for 48V should be not more than 22mF. for higher voltage version, the values are below 10mF. this because the high current required to charge the caps at start up in the given start-up interval. if a larger capacitance is needed, the start-up time should be increased as well as the bias capacitor from primary side. the values chosen for the capacitors of the available configurations covers almost all the required capacitance values for amplifiers which would be used with.
the amplifier which you want to supply was designed to be powered from a mains transformer with rectifier bridge and large capacitors, which in case of using a smps are not necessary to be so big. even if is a class D or T amplifier, being a single rail supply will definitely use BTL output configuration where bus pumping is not present, so using such a big capacitance is not required. also, the SMPS500RS has regulated output voltage.
if you are not willing to remove the caps, you can leave them on the board and i will explain you how to increase the soft-start time if needed to avoid over-current tripping during start-up.

Duffy, please contact me by mail regarding the order confirmation. thank you.
 
kristleifur: the maximum capacitance value depends on the start-up time and output voltage and it decrease exponentially while the output voltage increase. for SMPS500RS-24V a total capacitance of 22mF is not a problem, and the maximum should not exceed 68mF. for 30-36V version, the capacitance should not exceed 33mF and for 48V should be not more than 22mF. for higher voltage version, the values are below 10mF. this because the high current required to charge the caps at start up in the given start-up interval. if a larger capacitance is needed, the start-up time should be increased as well as the bias capacitor from primary side. the values chosen for the capacitors of the available configurations covers almost all the required capacitance values for amplifiers which would be used with.
the amplifier which you want to supply was designed to be powered from a mains transformer with rectifier bridge and large capacitors, which in case of using a smps are not necessary to be so big. even if is a class D or T amplifier, being a single rail supply will definitely use BTL output configuration where bus pumping is not present, so using such a big capacitance is not required. also, the SMPS500RS has regulated output voltage.
if you are not willing to remove the caps, you can leave them on the board and i will explain you how to increase the soft-start time if needed to avoid over-current tripping during start-up.

EXCELLENT information. Thank you so much.

I am perfectly willing to leave out the capacitors. I'll try without them :)
 
kristleifur: the maximum capacitance value depends on the start-up time and output voltage and it decrease exponentially while the output voltage increase. for SMPS500RS-24V a total capacitance of 22mF is not a problem, and the maximum should not exceed 68mF. for 30-36V version, the capacitance should not exceed 33mF and for 48V should be not more than 22mF. for higher voltage version, the values are below 10mF.

This posting caught my attention. I am in a similar situation to kristleifur with regard to powering an amp that was designed for a big toroidal transformer.

I am currently building a ß24 from AMB and each channel has 4x2200uF = 2.2mF per half side of the balanced circuit.

I have 2 SMPS800R configured for +/-40V in transit right now. Do I need to do anything special? I was assuming the slow start could handle this.


Cheers

Thomas
 
Thomas, adding 2200uF more to the existing caps would not affect the performances, or the startup time. you could add up to 4700uF on each rail, over that should consider to increase the start-up time only.

cOZ: the aux. output uses a 7812 regulator, it could supply up to 1A, if the main output is loaded with at least 0.5-1A, if the main output is not loaded, the power supply might enter in burst mode and there will be not enough current for the aux. supply.
 
Hi Cristi,

I Need a PSU around +-70v and +-12v as auxiliary.
I dont understand how your site works. No details about PSU in the page where all are listed, and not so much in detail page of each one. And i don't know how to order the one i would need:
+-72v and +- 12v auxiliary.
I will put all the stuff in the loudspeakers enclosures:
- L20D for the basses. With 1khz cut-off.
- A current feedback analog amp (with bad power supply noise rejection and bandwitch >3Mhz) for treble above 1Khz.
On the auxiliary:
- PGA2311 for volume control (+-6V)
- Little electronic (amp protections and soft power) with 3 relays.
- May-be 2 DACs in the next future.
I have some questions, as i never used SPMS for audio .
Can-i espect a better HF rejection if i use a emitter follower power transistor in serial with the SMPS and additional parallel electrolytic condensers (with soft power on protection) for my analog amp ? How far from my amps is best for the (shielded) SMPS (electromagnetic coupling) ?
Thanks in advance.
 
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