dual power supplies

[shangkaishin]

Hi,

I am building a digital filter circuit and I am having trouble finding a suitable power supply. I need a dual output, wall socket plug-in +12VDC power supply. However, everything I come across has pin connections like those on breadboards or DAQ's or switchboards like this one: https://www.trcelectronics.com/ecomm/pdf/abf04.pdf


I do not know how to adapt a wall outlet to fit that kind of input. Can anyone recommend a cheap plugin dual power supply? Alternatively, does anyone know an easy way to connect pins to a regular wall outlet?

Thanks!

 

[audioguru]

Why do you need a dual polarity power supply/ Many transistor or opamp circuits can easily be biased and capacitor coupled to use a single positive supply.
Why do you need a total supply voltage as high as 24V? Many audio circuits work perfectly from +9V.
Do you need a regulated voltage supply? Many circuits don't need voltage regulation.

 

[shangkaishin]

The circuit is actually multistage and includes multiple filters, amplifiers and I-V converters. The schematic was given to me because it worked before. I don't fully understand the analog circuitry behind it so I couldn't tell you if the bipolar power supply is strictly necessary or just more convenient. However, the design calls for both + and - 12V. I do need the voltage supply to be regulated. Essentially, I want to plug it into the wall to power the circuit, pack them together somewhere and then forget about them.

 

[audioguru]

I have never seen a plus and minus 12V regulated power supply for sale. It would be simple to make one.

 

[tomizett]

Simplest solution would be to get a 12v AC adapter (the kind that has only a transformer in it) and build a voltage doubler into your circuit, plus probably a pair of linear regulators, to give the required +/-12v. Such simple plug-in units are getting quite rare though, as they get replaced by SMPS units.
Failing that, get a 24v supply (with an output isolated from ground) and then derive a half-rail (ie, +12 with respect to your PSUs 0v) from that using a power op-amp and ground that rail (so that what your power supply calls "0v" becomes -12v with respect to earth).
I'm sure there are also DC-DC modules available off-the-shelf that would do a direct conversion from your preferred input voltage.

I take it the current is quite low?

 

[shangkaishin]

OK, I think I have found one that might work? https://www.trcelectronics.com/ecomm/pdf/abf04.pdf

any tips on how to plug this in to a wall outlet?

 

[shangkaishin]

and yes the current draw is very low, I was told a few hundred mA was all I needed

 

[KMoffett]

How about two SMPS 12VDC wall plugs. Switch the 12V side On/Off with a DPST switch.

Ken

 

[KeepItSimpleStupid]

This https://media.digikey.com/pdf/Data Sheets/Elpac PDFs/WM REV A.pdf does show they exist. They have some +12, -12 and +5 wall warts or "desktop" supplies. "Desktop" is like a laptop charger.

If the current draw is low, you could split a 24 V supply using a supply splitter IC. Not sure if they are available to 24 VDC though.