Hey All!
I'm new here. Been watching Dave's videos for some time and even though I don't really work in electronics or get involved with complex systems I've always found them entertaining. I thought I'd drop by and ask for some advice.
I'm a bit of a valve/tube guitar amp enthusiast and I've been thinking about making some DC-DC converter high voltage supplies. Something like 12vdc to 300vdc and I'm thinking around 10mA should be fine. 12vdc will provide filament voltage and 300vdc@10mA (or around that) should give plenty of options for running common preamp valves.
I've seen the nixie supplies that use 555 Timers or MAX1771 chips in boost converter setups and both will work for audio with some extra filtering, however I like the idea of putting together a small flyback converter. I think the isolation that type of circuit provides would be of an advantage if I made a valve preamp or pedal for example.
Here are some controllers I've found.
http://www.linear.com/product/LT3958http://www.linear.com/product/LT3748http://www.linear.com/product/LT3757The LT3958 contains a circuit that provides 300vdc@10mA but isn't specifically stated as providing isolation. The connections between the device and the transformer secondary are via ground though? The example circuit does not contain a switching transistor either.
Other devices I've found that seem to deliver high voltages and currents are photo flash cap chargers. I've not looked into these much as I imagined they may not be ideal for my purposes. I imagine these may be better at charging caps at intervals rather than being used as continuous supplies.
Just after some opinions from guys that know way more about this than myself! I've probably overlooked a lot of other solutions. Maybe some other SMPS topologies can be shrunk down to get what I'm after? I'm also looking into this with a view to practicing using LTspice and Eagle... both of which I'm very much a n00b at!
Peace!