Hai, Do anyone know of a simple HV PSU around 280~300V to drive a Quad 22 control unit? 😕
I don't really wan to use a heavy and bulky power transformer for the PSU...
I have seen some 555 design PSU but they made that for nixie tubes..
So if anyone has an idea please do comment in this thread
Thank You 😀
I don't really wan to use a heavy and bulky power transformer for the PSU...
I have seen some 555 design PSU but they made that for nixie tubes..
So if anyone has an idea please do comment in this thread
Thank You 😀
Have a look at the datasheets for many of the SMPS controllers, they can all be adapted to produce HT output.
SG3525 is pretty simple to use.
SG3525 is pretty simple to use.
I would build a well filtered PSU for the QUAD 22, but if you want to do it on the cheap then go to your local auto supply store buy a small AC inverter similar to this one, feed it with an old 12VDC wallwart that you may have laying around. Use the 12VDC to feed the filaments and FWR, RC filter the 220V to get the HV. Get a nice looking case to house everything, so the HV is not accessible to kids and small animals... Warning - while this works but do so at your own risk.
On this thread i made, trobbins suggested the same solution but he also added that hose inverters actually step up to unregulated high voltage DC first before converting to AC. You might be able to tap to those high VDC although theyre unregulated http://www.diyaudio.com/forums/power-supplies/255978-modifying-ebay-boost-converter-tube-amp-b.html
The Antek transformers are not that bulky and are incredible value for the money. Add a rectifier, a cap, and a voltage regulator such as my 21st Century Maida Regulator and you have an excellent, quiet supply.
~Tom
~Tom
Personally I would go the transformer and bride + smoothing route.
A SMPS is going to be pretty much the same size anyway although it will be lighter.
A SMPS is going to be pretty much the same size anyway although it will be lighter.
+1 to tom and nigel, I would do the same, but the OP wants to avoid "big" PT.
Cool, have to try it sometimes.
An advantage of the 12VDC external plugpack, and either including the 12/270V DC/DC in the control unit, or in a small attached housing, is that the mains AC can be kept away from the control unit, and can be handled by a commercial power unit (ie. not diy).
Mains hum is removed, both from heater and HT entry paths. The heater and HT supplies may well have a minute level of smps ripple, but I suggest that is a red herring and if paranoia sets in then some judicious hf filtering can get anything down to below your oscilloscope optic nerve.
Mains hum is removed, both from heater and HT entry paths. The heater and HT supplies may well have a minute level of smps ripple, but I suggest that is a red herring and if paranoia sets in then some judicious hf filtering can get anything down to below your oscilloscope optic nerve.
How much current is needed to drive a Quad22- pre?
I don´t think that a big transformer is needed.
A simple 1:1 Transformer with diodebridge and CRC will be good enough.
Hilmar
I don´t think that a big transformer is needed.
A simple 1:1 Transformer with diodebridge and CRC will be good enough.
Hilmar
What about 2 12VAC transformer back to back?? 12V to 230Vac ? after rectifier can cap it should be enough to power a Quad 22 right?
Sure you can do that, but it's going be about the same price/size as a small PT purposely made for preamps.
I think it would be too bulky, whereas OP prefer to reduce iron weight. Not to mention very bad efficiency.
LOL yea brainfart on my side..
Personally, i think SMPS is the best thing since sliced bread.
Less weight and space, easier regulation, whatever ripple is there won't be audible, most of the time it's cheaper, high efficiency. What's there not to like?
I just learned about SMPS just a few days ago and wished i had known earlier. Imagine all the money one could save from not having to buy heavy transformers and pay even more expensive shipping cost from the weight itself.
Personally, i think SMPS is the best thing since sliced bread.
Less weight and space, easier regulation, whatever ripple is there won't be audible, most of the time it's cheaper, high efficiency. What's there not to like?
I just learned about SMPS just a few days ago and wished i had known earlier. Imagine all the money one could save from not having to buy heavy transformers and pay even more expensive shipping cost from the weight itself.
SMPS supply not well shielded causes white noise similar to a phono preamp with volume at half. the lower the amp is played the more noticeable it becomes
A mains input smps may well generate noise in to the audio spectrum if not well managed in the smps and allowed to couple over, due to the mains 2f energy within.
But a dc/dc smps (such as 12VDC to 300VDC) does not intrinsically have the same noise structure in the audible range as there is no 100/120Hz component.
But a dc/dc smps (such as 12VDC to 300VDC) does not intrinsically have the same noise structure in the audible range as there is no 100/120Hz component.
An LLC SMPS might be the answer.
LLC radiates less noise as it is a sine wave going into the SMPS transformer.
LLC radiates less noise as it is a sine wave going into the SMPS transformer.
Apparently it needs 330V 4mA, 6.3V 1.1A.
So you'll want the first transformere to be 9VA or more, but the second can be 6VA (or maybe even 3VA, although the loasses may be too great with such a tiny transformer). I suspect you may only get 250Vdc or so, at the output though.
So you'll want the first transformere to be 9VA or more, but the second can be 6VA (or maybe even 3VA, although the loasses may be too great with such a tiny transformer). I suspect you may only get 250Vdc or so, at the output though.
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