You have said right from the beginning that your requirement is for a single 22 volt DC supply of 1.1 amp capability. That means the original power supply has just two wires feeding the pedal.
A dual or split supply is totally different as it has two output voltages, one positive and one negative. The same rules apply to calculating voltages and current though.
You haven't got a dual supply though, and you also haven't got a dual or split winding transformerJust a single winding.
Your transformer is rated at 22 volts AC and can deliver 1.4 amps into a resistive load. That means your transformer is a 30VA rated unit. We normally use the term VA or 'volt-amps' and not watts when dealing with transformer specifications.
Once you rectify and smooth that AC voltage then it can not supply (as we have mentioned) the same 1.4 amps into a resistive load, it must be derated (multiplied by) by that factor of 0.61 which gives just 0.85 amps.
thanks Mooly, although i'm kinda upset that i'll have to return the transformer and the shipping is gonna be from my pockets
(is it possible to buy another transformer 22vAC 1400mA and use 2 transformers [each for a singke polarity] with 1 lm350 for each? is there any benefits for the final results or it doesnt make any diffetence?)
sorry for misrespecting you that day
thanks for bringing me hope again
edit: a friend of mine, the same who instructed me about the lm350k and supplied me with a can from National + mica isolator and poly spacers for screws... he said the pedal was fed by symmetrical DC because he saw on the schem of a previous version of this pedal it had -+ 15v
i have great respect for his friend so i considered it true, he also said my transformer could do it
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You can get +/-15V from a single or dual winding transformer.
You would need to rectify it, smooth it then regulate it.
Or rectify it, smooth it then DC DC convert it if uses a lot of power.
No need to apologize, as I still think you are wrong
Suggest you think some more about what you are doing. You are certain that a commercial product was successfully marketed and sold in an unuseable state, and continues to sell years later? The problem is much more likely to be that some cable or connector is broken or you have some DIY element in your signal chain that is the root cause.
Suggest you think some more about what you are doing. You are certain that a commercial product was successfully marketed and sold in an unuseable state, and continues to sell years later? The problem is much more likely to be that some cable or connector is broken or you have some DIY element in your signal chain that is the root cause.
No need to apologize, as I still think you are wrong
Suggest you think some more about what you are doing. You are certain that a commercial product was successfully marketed and sold in an unuseable state, and continues to sell years later? The problem is much more likely to be that some cable or connector is broken or you have some DIY element in your signal chain that is the root cause.
the pedal and original PS are okay
brazilian electric net is a joke full of bad harmonics and interferences...
i don't use energy conditioner for my tube amps because they only started screaming after i pushed the HT-Dual into their input, the correct should buy the device to filter all energy from the wall, but they cost at least 20x more than building a power supply with ground and tad less noise; (the pedal is good im sure, but it amplifies alot the signal to create the overdrive and when it amplifies bad signal it will obviously cause microphonics at an unwanted level)
maybe in the uk and so they don't need to dump bad signal into the ground wiring, but when it comes to brasil, well, things are different in hell and the cash income is real short, truth be told:
i'm moving to uruguay this month because its better there and my rent expires day 19... sad part is i don't have the high payment truck drivers ask to take my home studio, dogs and furniture there, you guys are very... very lucky been born outside brasil
well, at least i think this PS is gonna be finished
real thanks
before i vanish into oblivion, check this band i play in
facebook.com/netun0
thanks for ya'll time
(edit: if advertising that FB page is unallowed i just scrape it away from the post, theres no need to punish me)
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You should be able to parallel two identical windings in theory (make sure the phase is correct) possibly also including two series balancing resistors for each winding.
Paralleling/and/or series connecting primary windings is common practice when wiring a transformer for 230 or 115 Vac.
Its a messy and bulky option though. Far better to have the correct one in the first place tbh.
I have a lot of friends who I deeply respect. I also know that they are wrong once in a while. Two different things.
You could ask your friend how they could make +/-15 from a single +22V input?
This may trigger him to think ;-)
(And yes, it IS possible).
Jan
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thanks Jan
the correct specs needed for that PSU: 22vDC center positive
the transformer is mains AC into 22v AC, 1,3 mA
the transistor to regulate is an old metallic two legged lm350k
i have the diagrams from this topic saved on this phone
but after all, i still use the awitching psu that came stock, i must build this PSU asap, but at the moment i am in the search of motivation... theres a microfone signal splitter in the queue too
edit: picture uploaded, about the psu specs
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This is all wrong. The PSU delivers 22V DC which is what your unit needs. No idea where that 1,3 mA comes from.
LM350K is not a transistor, it is an integrated linear regulator with three connections. 2 pins and the body which IIRC is the output. Adjustable output 1.2V to 25V. Neatly fits an unregulated 22V.
My bet is that there is no +/-15 inside, but regulated 18VDC and that the active part runs unipolar with devices biased midpoint. You really should try to get a schematic of that unit, not 'something someone sometime seemed to remember'.
We take you serious, you should take it serious too.
Jan
I used a Class 2 linear transformer through a CMC to power a DC-DC switching step up, this goes to a cap multiplier, and that is followed by a LDO linear regulator like TPS7A4001, which is followed by a CRCRC filter. DC-DC step up is isolated and moves the AC noise to 400kHz where it’s easier to filter and outside of audio band. The 60Hz mains is left behind. Higher current linear regs can be used and some even parallelized for more current. The result is something that resembles a battery even though mains powered.
I use this system all the time now for Preamps and headphone amps. Works like a charm.
Here is an example of one for 315mA and +/-18v.
I use this system all the time now for Preamps and headphone amps. Works like a charm.
Here is an example of one for 315mA and +/-18v.
Hi Jan,
I think the DC-DC or SMPS topology and concept of commodity ($15) 24v 5amp LED SMPS to $7 DC-DC step up, followed by a cap multiplier might be the simplest way to get a very low noise 1100mA 22vdc PSU. All that is needed is a cap Mx - which is just a single MOSFET (if you can handle 4v dropout) or two BJTs if you want 1.3v or more of dropout. Even the usual linear trafo feeding a bridge and small 10mF smoothing cap and cap Mx is better than just a plain CRC. The 2v dropout might be perfect to take 24v to 22v.
The cap Mx is low cost and easy to build - available here.
https://www.diyaudio.com/forums/pow...sy-capacitance-multiplier-60.html#post5576523
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