Hi,
I would like to know if there are known circuits that permit to have low-noise dual power supplies at +200 and -200V for circuits that need less than 100 mA.
Thank you in advance,
Kind Regards
Roberto
I would like to know if there are known circuits that permit to have low-noise dual power supplies at +200 and -200V for circuits that need less than 100 mA.
Thank you in advance,
Kind Regards
Roberto
If it doesn't need to be accurate: transformer - two rectifiers - two series of RC sections to filter off the ripple?
Do you already have the power transformer that you want to use?
What kind of accuracy? What is the behavior of your AC line voltage,
that will make a big difference with a linear regulator.
What kind of accuracy? What is the behavior of your AC line voltage,
that will make a big difference with a linear regulator.
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LR8s are noisy as hell, and I don't think they can handle 100 mA. Otherwise, with two secondary transformer windings, you could just use two positive regulators and ground the output of one of them.
Yes, do you need tracking supplies, or what kind of accuracy do you need?
What kind of circuit will this power? It's not a power amp, preamp, or headphone amp.
What kind of circuit will this power? It's not a power amp, preamp, or headphone amp.
The LR8 is a poor device for this purpose, so keep looking.
Here's an example of a older circuit. You would use two isolated secondaries, and two regulators
with their outputs connected in series. The semi devices would have to be updated, and bigger heat sinks.
http://www.electroniq.net/power-sup...e-adjustable-regulator-circuit-schematic.html
Here's an example of a older circuit. You would use two isolated secondaries, and two regulators
with their outputs connected in series. The semi devices would have to be updated, and bigger heat sinks.
http://www.electroniq.net/power-sup...e-adjustable-regulator-circuit-schematic.html
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The noise will get a lot lower when you decouple Rs, provided it doesn't destroy the pass transistor or overheat the LR8 at start-up.
With separate secondary windings and rectifiers, you could make two such circuits, ground the positive output of one of them and use the side you would normally ground as the negative output.
With separate secondary windings and rectifiers, you could make two such circuits, ground the positive output of one of them and use the side you would normally ground as the negative output.
@MarcelvdG basically a low pass filter before the gate/base of the mosfet/NPN, thanks.
Will grounding the other side guarantee a stable low Zout negative power supply?
Will grounding the other side guarantee a stable low Zout negative power supply?
No, more like extra feedback around the LR8, similar to ADJ decoupling for an LM317. It may be necessary to add a diode (1N4007 or so) in reverse from input to ADJ.
It shouldn't matter for stability or output impedance which side of the output you call ground.
It shouldn't matter for stability or output impedance which side of the output you call ground.
Here are two examples of high voltage supplies, one positive and one negative but with both using a NMOS as pass element.
They can be made adjustable, and have been actually tested:
https://www.diyaudio.com/community/threads/simple-hv-series-regulators.198986/post-2753552
https://www.diyaudio.com/community/...voltage-regulator-circuit.180140/post-2417349
I have also described other circuits, but they are more sophisticated and use an opamp
They can be made adjustable, and have been actually tested:
https://www.diyaudio.com/community/threads/simple-hv-series-regulators.198986/post-2753552
https://www.diyaudio.com/community/...voltage-regulator-circuit.180140/post-2417349
I have also described other circuits, but they are more sophisticated and use an opamp
@MarcelvdG and @Elvee
Thank you, I will try to simulate both options and then built it to see how thye work for this specific application.
Thank you, I will try to simulate both options and then built it to see how thye work for this specific application.
For basically the same front end as shown in your simulation, I just used a simple Maida regulator for the positive supply, although only 140V @ 30 mA. I didn't take the shunt load resistor to a negative voltage as I didn't need the swing, but you could just make a negative version. Example in post #28 here.
No problem with noise.
No problem with noise.
Two of these in series:
https://www.gyraf.dk/gy_pd/g9/g9pd.htm
Just modify the feedback network.
Or a single 400v dc supply with virtual ground.
Or a simple zvs resonant booster from a 12.6 v supply that you might use for fillaments too.
https://www.gyraf.dk/gy_pd/g9/g9pd.htm
Just modify the feedback network.
Or a single 400v dc supply with virtual ground.
Or a simple zvs resonant booster from a 12.6 v supply that you might use for fillaments too.
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