Juma's Easy-Peasy Capacitance Multiplier

[Skylar88]

Slow ramp up

I've noticed the cap multipliers on my ACA's ramp up the current real slow - something like 30 seconds, iirc. Which component/s can I change to get faster ramp up to full current?

I've used the values shown in the schematic below.

 

[juma]

Change R5 and R6 to 1k or so.
And please stop spreading the confusion by repeatedly showing that schematic drawing - IRF610 can not be successfully used to supply ACA or any other power amp, it's good only for preamps and headamps.

 

[Skylar88]

Change R5 and R6 to 1k or so.
And please stop spreading the confusion by repeatedly showing that schematic drawing - IRF610 can not be successfully used to supply ACA or any other power amp, it's good only for preamps and headamps.

Thanks for the advice Juma.

And sorry for posting that erroneous schematic. Didn't realize that I have posted the one with the IRF610. I have now deleted it from my computer.

 

[sinova]

I came from the TDA7279 lunch amp thread, been modding it and good results so far.
I wanna try this easy cap multiplier so far the IRFPs are nonexistent where I live, so I want some common alternatives, I looked in some of my stashes and found only one MOSFET the MTP3N80, so which parameters I should check in the datasheet to adjust the circuit.
It checks on current and voltage loading (I want 2A to be safe).
Thanks XRK and Juma (and others), really awesome thread.

 

[sinova]

I should add that the Juma Easy Capx performs really well on simulation, I tried K-Multiplier, it's nice, but Juma's beats it in simplicity and BOM cant get any good really.

 

[Ripcord]

A little OT-Prasi gerbers

I like to import gerbers in to Diptrace, which is what I use, and I can't seem to import the drill files. Prasi's designs are excellent but sometimes I like to put them in Diptrace so I can change component sizes for parts I already have. Any idea how to import the drill file Prasi uses to Diptrace? You can move this if it's not in the right place.

 

[prasi]

I like to import gerbers in to Diptrace, which is what I use, and I can't seem to import the drill files. Prasi's designs are excellent but sometimes I like to put them in Diptrace so I can change component sizes for parts I already have. Any idea how to import the drill file Prasi uses to Diptrace? You can move this if it's not in the right place.

Hi Ripcord,
I dont use diptrace. So will not be able help you.
I could get you the files imported into sprint, so you could have a sprint layout file ready for editing.

You could contact some of the dip trace users that you know who are willing to help you.

regards
Prasi

 

[Ripcord]

Thanks Prasi. I will try the Diptrace forum and see if someone knows. Thanks for the offer of the Sprint files. Very generous! I'll let you know if I don't get anywhere with the Diptrace people.

 

[gannaji]

If the Eagle schematic and board files are available, then they can be converted to Diptrace files very easily.
Can I request Dear Prasi to post the final original Eagle files ?

 

[prasi]

If the Eagle schematic and board files are available, then they can be converted to Diptrace files very easily.
Can I request Dear Prasi to post the final original Eagle files ?

Sure, I will do it in the evening.

 

[Ripcord]

Eagle board files are definitely my favorite way to get pdb's in to Diptrace. Prasi, if it's not to much trouble, I would love the .brd files for the cap mult. Thanks much.

 

[prasi]

Here you go..

Funny, I posted eagle files (DLH amp) in this thread, thinking thats where they are required.
DLH Amplifier: The trilogy with PLH and JLH amps

Must be loosing my mind.

Regards
Prasi

 

[Ripcord]

Thanks a bunch!

 

[szpunk]

That PSMN1R025YLD looks like an awesome FET, however it has 25v limit which sort of limits it to 15v class A head amps or maybe preamps. A 25v typical class A supply might be too much. I like the 890 microOhm Rs_on, and continuous 100A!

This could be a very useful little FET to make a cap multiplier for my F5 head amp.

http://datasheet.octopart.com/PSMN1R0-25YLD-NXP-Semiconductors-datasheet-62336464.pdf

Is the input capacitance too large to use it as an audio OPS?

There has PSMN1R0-40YLD

https://assets.nexperia.com/documents/data-sheet/PSMN1R0-40YLD.pdf

 

[xrk971]

I just built up the Prasi 100mm square dual rail, dual channel layout. Under no load conditions and testing with a 10amp DC-DC step up as input. Will use it to feed an off-board CRC filter so small on-baord caps are used. This may become a nice adjustable (20v to 35v) dual rai voltage regulated high current PSU for my ALPHA amps.

Here is some initial testing for +/-28v output, still need to add output CRC filter.

More here:
Aksa Lender P-mos Hybrid Aleph (ALPHA) Amplifier

 

[potepuh]

Where did you get those nice litle DC-Dc converters?

 

[prasi]

Nicely done...
I think it will be an excellent supply for testing of different amps, be it class a or ab

 

[xrk971]

Where did you get those nice litle DC-Dc converters?

Search for “DC Boost 10 amp LED” it’s about $5 to $8ea.

 

[xrk971]

I was just thinking that I could make this a complete Prasi power supply system if I use the Prasi/Proejct16 CRC boards as the dual mono CRC (sans diode bridges - replace with jumpers on positive flow ones).

 

[thimios]

I just built up the Prasi 100mm square dual rail, dual channel layout. Under no load conditions and testing with a 10amp DC-DC step up as input. Will use it to feed an off-board CRC filter so small on-baord caps are used. This may become a nice adjustable (20v to 35v) dual rai voltage regulated high current PSU for my ALPHA amps.

Here is some initial testing for +/-28v output, still need to add output CRC filter.

More here:
Aksa Lender P-mos Hybrid Aleph (ALPHA) Amplifier

Theese are non isolated.
How you manage to solve the common gnd and safety earth connection(two smps using main earth & - connection)?