CurtPalme.com Home Theater Forum

[macgyver655]

Ever wonder whats really inside a HVPS? This is an early model Ampro. Yes I was bored today. This is the best I felt like cleaning it.

[dturco]

Thanks Mac. I was wondering what was in there. What is there is not what I expected. But I don't really know what I expected either, but it wasn't that. I guess I was thinking like a toroid or El coil? Not that I would have a clue but it's nice to know.

Thanks again.

[Curt Palme]

Judging by those poor capacitors, you sure have a dusty shop.

I've got a couple of late model Ampro 3600 LVPS coming your way along with a parts unit. THey are leaving tomorrow.

I'm also working on an Alpine car amp. One of the SMT switching chips overheats, then a couple of the channels shut down.

I put on my best soldering suit, and managed to install a new upC 494 switching chip, which does exactly the same thing. Go figure. I was all proud of myself too, swapping out the SMT chip.

No luck finding an Alpine schematic online, so I'm going in with the uPC 494 data chip to see why this thing is running hot. THe unit is a 5 channel amp, and there's two identical SMPS in the same amp, so hopefully I'll nail it. If not, let me know if you want a go at it. It's a really nice amp, but I think I overheated it under my seat a few years ago. Before the switching chip overheats, the amp channels it is powering work fine, then they start distorting as the chip shuts down.

It's kinda cool I can (barely) put my finger on the hot chip, my finger acts as a heatsink, and the channels start working again.

[Curt Palme]

Judging by those poor capacitors, you sure have a dusty shop.

I've got a couple of late model Ampro 3600 LVPS coming your way along with a parts unit. THey are leaving tomorrow.

I'm also working on an Alpine car amp. One of the SMT switching chips overheats, then a couple of the channels shut down.

I put on my best soldering suit, and managed to install a new upC 494 switching chip, which does exactly the same thing. Go figure. I was all proud of myself too, swapping out the SMT chip.

No luck finding an Alpine schematic online, so I'm going in with the uPC 494 data chip to see why this thing is running hot. THe unit is a 5 channel amp, and there's two identical SMPS in the same amp, so hopefully I'll nail it. If not, let me know if you want a go at it. It's a really nice amp, but I think I overheated it under my seat a few years ago. Before the switching chip overheats, the amp channels it is powering work fine, then they start distorting as the chip shuts down.

It's kinda cool I can (barely) put my finger on the hot chip, my finger acts as a heatsink, and the channels start working again.

[Tom.W]

The high voltage duadrupler circuit.......

http://www.falstad.com/circuit/e-voltquad.html

The output voltage is approximately 4 times the input voltage but less current.

[Curt Palme]

BTW, if you have an inductor ringer, check the transformer between the HVPS section and the LV section. My theory is that teh transformer has shorted turns in it, killing the switching circuit, and thus no HV.

[Curt Palme]

BTW, if you have an inductor ringer, check the transformer between the HVPS section and the LV section. My theory is that teh transformer has shorted turns in it, killing the switching circuit, and thus no HV.

[macgyver655]

[macgyver655]

[tse]

Drawing.........

Scott

[macgyver655]

Thats pretty cool Scott. Got any of them for the newer supplies?

[Nashou66]

Potting Material:



nashou

[macgyver655]

[Nashou66]

Not sure, but i didn't look to well either.

Athanasios

[macgyver655]