Hey guys, is there any direct replacement TO220 replacement transistor pair that can substitute the parallel arrangement of TO92 that was manufactured with this prone to failure powersupply? The originals are C9013 but I’m tired of the reworking of these supplies when they fail, I used a 12v positive regulator I series with the B+ in to prevent alternator swinging, those hold out but is there just a drop in robust component that doesn’t need 4pcs to power it and can be durable without the inline regulator?
The D44vh10 is a fast transistor. The pin configuration is different (changed from reversed).
I had the same problem with coustic crossovers. In those, I converted to FETs and made a clamp to heatsink them to the bottom cover. It took more time but they never came back (not with that problem).
I had the same problem with coustic crossovers. In those, I converted to FETs and made a clamp to heatsink them to the bottom cover. It took more time but they never came back (not with that problem).
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Is there a breakdown of your schematic for that FET conversion Sir Babin?
The re-repairing is eating away the pads, very frustrating.
The re-repairing is eating away the pads, very frustrating.
I looked for notes and couldn't find them. You can remove the parts that are in it and use the same basic circuit that is used for a 494 driving IRFZ44 FETs,
Use a 1k pulldown that connects between pin 7 and pins 9/10 (one resistor per pin). And use a 100 ohm for the gate resistor. You may have to lower the gate resistor value since it's likely operating ad a much higher frequency than a standard amp.
Use a 1k pulldown that connects between pin 7 and pins 9/10 (one resistor per pin). And use a 100 ohm for the gate resistor. You may have to lower the gate resistor value since it's likely operating ad a much higher frequency than a standard amp.
I've tried a handful of transistor replacements some held up and some didn't (first pic). I'll see if I find the list I tried.
My go to circuit now is similar to the earthquake attached; I use a MIC4424 and any PS FET I have at hands reach during the repair, I just tweak the gate resistor to suit. I use Ray Chem's "Heatpath" and some E6000 to secure the FETs and perf board to the frame.
The second pic was trial, now I solder it on perf board and to the main PCB, as you mentioned, the pads and traces go pretty fast..
Prolly later on I may make a printed PCB, based on freq.
https://www.ebay.com/itm/2737999096...40QiVbuDhfiIgnWDyhG5f/GQ==|tkp:Bk9SR4rp9-zFYg
My go to circuit now is similar to the earthquake attached; I use a MIC4424 and any PS FET I have at hands reach during the repair, I just tweak the gate resistor to suit. I use Ray Chem's "Heatpath" and some E6000 to secure the FETs and perf board to the frame.
The second pic was trial, now I solder it on perf board and to the main PCB, as you mentioned, the pads and traces go pretty fast..
Prolly later on I may make a printed PCB, based on freq.
https://www.ebay.com/itm/2737999096...40QiVbuDhfiIgnWDyhG5f/GQ==|tkp:Bk9SR4rp9-zFYg
Attachments
Thanks for keeping me updated, could I use the perforated circuit board and solder pad the tabs of the FETs for dissipating, this setup does the FETs emit a lot of heat could I use that method and it runs reliable?
Minimal to zero heat from the FETs, I use the heat path and e6000 so I won’t have to drill the case.
I think most units the current draw is around 0.35A for a fully assembled.
I think most units the current draw is around 0.35A for a fully assembled.
Have you tried it without the driver, only using resistors? If you find the right combination of parts, it will greatly simplify things.