I've build a PS based on SMPS to replace a linear supply.
It uses a 12V SMPS driving this: MINI DC-AC Inverter 12V to 18V220V/380V 500W Boost Step UP Power Module New Hot | eBay
Unlike linear SMPS hate inrush. OTOH I'm using a 3300uf cap for filtering... Had to connect the HV power through a 300R resistor and jump it out with a time delay relay. Result? 340V filtered and excellent performance for something so cheap.
This could be a great SMPS for a car tube amp.
It uses a 12V SMPS driving this: MINI DC-AC Inverter 12V to 18V220V/380V 500W Boost Step UP Power Module New Hot | eBay
Unlike linear SMPS hate inrush. OTOH I'm using a 3300uf cap for filtering... Had to connect the HV power through a 300R resistor and jump it out with a time delay relay. Result? 340V filtered and excellent performance for something so cheap.
This could be a great SMPS for a car tube amp.
The first one is, the second one I haven't tested as I'm running it off a fixed voltage. The next time I open it up I'll dial the adjust pot and see if the output changes.
Secondly, I was mistaken. The cap is 2,200uF. I found it for $10 at a surplus store.
It uses a 12V SMPS (or a 12V car battery) to power the heaters and the above mentioned SMPS feeding into UF5408 diodes in a bridge connected to the 2,200uF cap through a 300R and a 100R resistor in series with a time delay relay that shorts the 300R after 8 seconds. The 100R drops 33V. The first cap in the schematic in the schematic is omitted, as are the relay and 300R.
Secondly, I was mistaken. The cap is 2,200uF. I found it for $10 at a surplus store.
It uses a 12V SMPS (or a 12V car battery) to power the heaters and the above mentioned SMPS feeding into UF5408 diodes in a bridge connected to the 2,200uF cap through a 300R and a 100R resistor in series with a time delay relay that shorts the 300R after 8 seconds. The 100R drops 33V. The first cap in the schematic in the schematic is omitted, as are the relay and 300R.
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Post #4 shows a choke between the HV inverter output and the diode bridge ????
I'd recommend deleting any such choke, and using UF4007 diodes, and fitting them on the inverter pcb with a close small electrolytic, as the smaller die and closer layout of those parts would minimise switching noise and alleviate it from splaying out.
I'd recommend deleting any such choke, and using UF4007 diodes, and fitting them on the inverter pcb with a close small electrolytic, as the smaller die and closer layout of those parts would minimise switching noise and alleviate it from splaying out.
What choke? There is a transformer feeding a bridge (UF5408) into a RC filter. As stated above the first cap is omitted. The schematic was just an example I pulled off the net 
In any case the entire thing has been running off and on for a week. There's no radiated noise to worry about as it's in it's own grounded enclosure 15" below the preamp it powers with some gear in between.
It's providing 120W to the amp, 70W to the heaters (there are 22 tubes in it) and 13W in the dropping resistor. The 12V SMPS is a "60A" Chinese LED supply (that's really closer to 40A judging by the components it's using).
The HV boost module is rated at 500W so 120W is a cakewalk for it. All in all I'm happy with the performance as it's less money to build than a linear supply and it's quiet.
I've built a second boost module supply that I'll be running off an ATX computer supply. It will use a much smaller capacitor! (100uF)
Cheers.
In any case the entire thing has been running off and on for a week. There's no radiated noise to worry about as it's in it's own grounded enclosure 15" below the preamp it powers with some gear in between.
It's providing 120W to the amp, 70W to the heaters (there are 22 tubes in it) and 13W in the dropping resistor. The 12V SMPS is a "60A" Chinese LED supply (that's really closer to 40A judging by the components it's using).
The HV boost module is rated at 500W so 120W is a cakewalk for it. All in all I'm happy with the performance as it's less money to build than a linear supply and it's quiet.
I've built a second boost module supply that I'll be running off an ATX computer supply. It will use a much smaller capacitor! (100uF)
Cheers.
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