Finished Car Amplifier schematic + PCB based on Kenwood KAC-716

[AUDISOUL]

Hi All,
My SMPS pcb at here:
http://www.diyaudio.com/forums/showt...99#post1785299

[AUDISOUL]

Hi All,

This all the designs (Post #616 and before) are design by my best Friend, But he dont want to giving this designs to all the guys so sorry and I cant help any body.dont mail me for the designs.He is hurt than I have stop to put his designs here.

[anselhu]

Who-to-use, high-power Class D schematic diagram of the hair to think about points. Thank you!

[lemoneasy]

hi,
can i replace fmu22r and fmu22s with FEP16GT? One positive CT and one negative CT. I'm still learning and I don't know what to look for but I need to find a local replacement. Any other common replacements?

[N-Channel]

Shouldn't be a problem, if you know voltage & current ratings of the diodes you're putting in. An easier approach: Sample some ultra-fast diodes from On Semiconductor. Specifically: MUR1620CT (+) and MUR1620CTR (-). Rated at 200PIV, and 8A per leg.

[lemoneasy]

Thank you! I can get that at a shop here

I took the liberty to attempt to test just the amplifier board today by hooking it up to a 30 volt 5 amp transformer i had around. The signal was a mono 3.5 jack i hooked up to a cd player. All I got was a loud buzzing... I unplugged it after a bit of smoke started coming from the board. All of the transistors stayed cool. I used a 470 ohm trimpot instead of the 330 one called for. As well i used a 2.3k resistor where it called for a 2k2 resistor.

Are my lack luster results due to using a 30-0-30 transformer and a cd player? I may have hooked up the transformer backwards, ie 40+ to 30- and 40- to 30+ as it was a surplus buy and had no markings. If the problem is the board itself I've got a lot of extra parts and I think I'll tear it down and start over. Maybe even try to be a bit more attentive this time...

[N-Channel]

Lemon,

First, start out by taking raw AC measurements across all the transformer secondaries before you connect them (assumed thru a rectifier & filter cap) to anything! Remember, if you read 30VAC, it's really peaking out at 42.42V, so you will wan to t de-rate your amp's voltage operating points, if possible.

Second, once you have sorted out all the secondaries, connect your rectifier bridge and two caps and measure the (+) & (-) voltages. Once you're satisfied you have good readings, correct any of the damage you mave done to the main amp board, and try it again.

Steve

[lemoneasy]

The bridge rectifier is putting out 36 volts dc. Shouldn't it be 60ish volts between the positive and negative wire? Anyways, I have one 3300 uF capacitor between positive and ground and negative and ground. I tried it again after cleaning up alot of stuff. I did it without a speaker and it stayed cool so I hooked it up to a speaker without a signal coming in and pooff the speaker went up in smoke. It was a free two way speaker with 120 watts max power, but the problem is that there was a hum while it was hooked up... and that it fried...

Why would the amp be putting out so much power with no signal? :| so I'm guessing that means transistors are fried. How can I check this?

[lemoneasy]

Im slowly working through my errors now. This is my first audio amplifier project, I'm a first year mechanical engineering student and it's quite humbling to learn how little you know!

Will I be able to test this amplifier on my 30 volt CT transformer? Which I now realize is putting out +/-18V DC at 5A max... I hope its sufficient because I'd like to test at a low voltage at first.

Thanks for the help! I'm sure a lot of you hate teenagers coming here requesting how to make a subwoofer amplifier but I'm trying to learn

[luka]

If you set your feedback to lower voltage, you will have lower voltage on output