I have seen alot of good reviews on this chip, and was wondering how well it will do on 14.6V into 4 ohms, I have a massive regulated 14.6 volt power supply, 50A continuous, have used it to run car amps in the past, also, are the LM3886's isolated from the case? (can multiple ones be mounted on same HS)
I assume you mean a single +14.6VDC output? You could probably rig it up to work with the +14.6V connected as a ground, the 0V output connected as V- supply, and a big capacitor at the output. And your reward for that effort would be about 1 W of power.
You might want to do a bit of reading up on the basics of chipamps in this forum. Quite a lot of good stuff.
You might want to do a bit of reading up on the basics of chipamps in this forum. Quite a lot of good stuff.
sorry for the misunderstanding, I had read elsewhere on the forum about someone running it from a car batt. with a modification to the circuit, I know that they are normally ran from CT transformers to get the standard V+ 0 V-, (I'm not that much of a noob javascript:smilie('
') was just looking for a cost effective way to use existing power supply.
') was just looking for a cost effective way to use existing power supply.About the lowest you can run an LM3886 is 16V total. The -9V must be met and the datasheet does indeed say minimum of 18V meaning +/-9V. But, if you test (as I did) you will find that if you run the negative rail at -10V and then the positive only needs about 6V to kick on. I made a simple circuit to create an asymmetrical supply to see how low it could go for an application using a 24V battery. You might find some parts that operate lower but you'd have to just buy a bunch and try them. Besides, THD improves quite a bit going from +/-12V to +/-15V. At 16V total you will have very little output power, not really worth it.
-TH
-TH
According to AN-898 the voltage between negative rail and ground must be 9 V or higher and the voltage between negative and positive rail must be 14 V or higher.leadbelly said:
Sasmit reports that the undervoltage protection has not worked reliable for him, however.
why not just get a higher voltage transformer, bridge rectifier, and a couple of big caps and be done with it? Adapting this 14.6VDC supply sounds like a big PITA. Why not just make it alot easier on yourself? Apex and Antek have some good deals on transformers, and I assume you've read Nuuk's Power Supply Article?
yeah, I think you're right about it being a PITA, the only reason I was trying to use the 14.6v PS was cost, I already have it, the transformer cost would be more than the rest of the project combined if bought new, but if I'm gonna have to build the PS from scratch I might as well go all out.
From what I've gathered during my searches of the forum the min. transformer rating should be 80-100VA per chip, therefore 3 800VA trans. (2,400VA) should be enough for 20, thinking about a wall of 20 of these, one chip per woofer. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-320 , that's $233 for woofers, $312 for transformers, $141 for chips, and roughly another $120 for support components (caps, resistors, bridge rectifiers, ect) so, about $800 total for a wall of 20 individually driven 12" subs, probly 1,200 watts total, should be pretty impressive anything I'm missing??
From what I've gathered during my searches of the forum the min. transformer rating should be 80-100VA per chip, therefore 3 800VA trans. (2,400VA) should be enough for 20, thinking about a wall of 20 of these, one chip per woofer. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-320 , that's $233 for woofers, $312 for transformers, $141 for chips, and roughly another $120 for support components (caps, resistors, bridge rectifiers, ect) so, about $800 total for a wall of 20 individually driven 12" subs, probly 1,200 watts total, should be pretty impressive
anything I'm missing??
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.