Yes. It can bring somewhat lower voltages than average by not driving the LEDS as hard, but its of no real consequence.1. Is it OK to use 2SK170GR for the unmatched J-Fets?
AndrewT responded to my question about costs, but did not answer my question:
Can someone provide a ballpark estimate of the cost to build a Mermerizse B1?
Thanks,
Jim D
Can someone provide a ballpark estimate of the cost to build a Mermerizse B1?
Thanks,
Jim D
AndrewT responded to my question about costs, but did not answer my question:
Can someone provide a ballpark estimate of the cost to build a Mermerizse B1?
Thanks,
Jim D
It's hard to give a decent estimate without knowing how you want to set it up. I'm going to throw out a wild guess of $250ish if you go bare bones (basic case, no custom front panel, no exotic parts, blue velvet pot, antek tranny). You could easily double or triple this price by upgrading some parts and going with a nicer enclosure.
AndrewT responded to my question about costs, but did not answer my question:
I think you can build a cheap one for under $150.It's hard to give a decent estimate without knowing how you want to set it up. I'm going to throw out a wild guess of $250ish
The final price ballpark depends on what you have to pay for those 7relays and 4FETs.
The matched quad of 2sk170's also is an expense. I would guess $20.00 max for 2sk170's.
As stated on other thread, IRFP9140, and IRF140s can be used, and they are occasionally a bit less expensive, at least in local suppliers.
As stated on other thread, IRFP9140, and IRF140s can be used, and they are occasionally a bit less expensive, at least in local suppliers.
I was able to source the Omron 12V relays from an AU source through the 'bay at a reasonable price. I was told they had "1000" at the time. I have sent them mail to ask if they have more & the current price.
Has anyone hotrod'ed the Mezmerize ?
I'm planning to hot rod mine. My understanding is the board is not optimized for it like the Hypno Blue, but it shouldn't be too hard to do. I was thinking of using a couple of 10,000uF off-board capacitors, a Mills 12W 10ohm resistor (also off board), and bumping up the MUR120 diodes to MUR820's. I'm not planning to run it too hot, so I'd just mount the MOSFETs to the chassis floor.
Here's a good link to a hot rod build using a regular hypno board.
Last edited:
Sure, I have, Woodturner-Fran has. Of course these were all done with the older boards.
use 2-3 2W 20-30R panasonic resistors (narrow leads)
Put IRF's bolted to bigger heatsinks or chassis floor.
Second 100uf cap becomes small MKP type cap of .2 or .1uf, make sure it fits.
use 2-3 2W 20-30R panasonic resistors (narrow leads)
Put IRF's bolted to bigger heatsinks or chassis floor.
Second 100uf cap becomes small MKP type cap of .2 or .1uf, make sure it fits.
Last edited:
Thanks, John
To determine the interest for the Omron relays, I have begun a thread in the Swap Meet.
A set of 7 Omron G6H-2 12V relays can be mailed within North America for $13. Other locations will be priced upon request.
Please express your interest here:
http://www.diyaudio.com/forums/swap-meet/177054-omron-g6h-2-12vdc-relays.html#post2361098
To determine the interest for the Omron relays, I have begun a thread in the Swap Meet.
A set of 7 Omron G6H-2 12V relays can be mailed within North America for $13. Other locations will be priced upon request.
Please express your interest here:
http://www.diyaudio.com/forums/swap-meet/177054-omron-g6h-2-12vdc-relays.html#post2361098
Has anyone hotrod'ed the Mezmerize ?
What's the max current that can be used on this board ?
Thanks,
Davide
1A, the diodes limit. If having the proper sinks. Up to 200mA is sane and does great with the existing psu caps even.
A silly questions (Sorry if these questions are usually recurrent).
How big must be the dissipators for the IRFP240 and 9240?, these mosfets must be matched?. The 7812 needs a dissipator?.
Thanks
How big must be the dissipators for the IRFP240 and 9240?, these mosfets must be matched?. The 7812 needs a dissipator?.
Thanks
A silly questions (Sorry if these questions are usually recurrent).
How big must be the dissipators for the IRFP240 and 9240?, these mosfets must be matched?. The 7812 needs a dissipator?.
Thanks
Hi / hola,
Do you need single heatsinks or dual heatsinks / necesitas disipadores individuales o para los dos mosfets?
Singles heatsinks: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=92394247&uq=634256597073549093
Dual heatsinks: http://es.farnell.com/jsp/search/productdetail.jsp?SKU=150016
Saludos / cheers
Felipe
Last edited:
the easy answers first.How big must be the dissipators for the IRFP240 and 9240?, these mosfets must be matched?. The 7812 needs a dissipator?.
The 7812 does not need a heatsink if the transformer is <=15Vac and only has to supply current for two 12V relays.
I suspect that 5V relays may require a heatsink on the 7812, if the transformer >12Vac.
The mosFETs do not need to be matched. You need 4 in total. They can all be different. But, you must check the voltage across the gate source as it affects the set up of the CCS. If a very high Vgs mosFET were used in a low output voltage Shunt regulator, you may find that swapping in a lower Vgs mosFET may improve performance. At very low output voltages, the shunt mosFET must be replaced by a BJT to eliminate the high Vgs, inherent in a mosFET, from the circuit.
The Power dissipation of the mosFETs is determined by the CCS current chosen, by the transformer Vac chosen and by the Output voltage and Average Output current chosen.
These power dissipation conditions vary between normal operating conditions and various FAULT conditions. The worst case fault conditions do not require the regulator to properly power the client circuit and thus temperatures do not have to be optimum for good performance. You can use survivability temperatures for these extreme worst case fault conditions. I recommend much lower temperatures for normal operation.
These decisions on temperature and the four power determining factors in the previous paragraph will determine what size, if any, heatsink should be fitted to the various mosFETs.
You will gather from this response that no questions are stupid.
Last edited:
- Home
- Amplifiers
- Pass Labs
- Mezmerize DCB1 Building Thread