Adjustable Voltage Regulator(s)

[Aiden1015]

I recently took apart a broken stereo and decided to use the powersupply as a benctop powersupply. after reverse engineering the cicuit board i discovered that the +-30dcv is unregulated.

i've seen the positive and negative adjustabe regulators but some of my projects will draw 4A (fuses on the circuit board are rated at 5A so i'm sure there's enough power to run some of my circuits)

where can i find either a positive and negative adjustable regulator at 5A in one or a 5A negative adjustable volage regulator, I found a positive regulator on digikey.

 

[saturn1bguy]

where can i find either a positive and negative adjustable regulator at 5A in one or a 5A negative adjustable volage regulator,

You could use two LM338s, one for pos and one for neg, if you have separate (isolated) transformer secondaries...

 

[Aiden1015]

assuming they are isolated would i hook up the 338 to the negative voltage the same as the positive or will that simply screw up the internal circuitry? I'm too lazy to look up the datasheet frankly.

if they aren't isolated do i have any other options?

 

[saturn1bguy]

assuming they are isolated would i hook up the 338 to the negative voltage the same as the positive or will that simply screw up the internal circuitry?

Each secondary gets its own bridge rectifier, filter cap, and regulator. The positive one is traditional. The negative leg, however, although wired the same, has its output tied to ground, and its ground becomes your regulated negative output.

If that doesn't make sense to you, I'll sketch it out.

 

[Aiden1015]

ah ok. yeah that makes perfect sense, idk why i didn't think of that. thanks.

 

[shokjok]

You will find circuit ideas in AARL Handbooks, Master Encyclopedia of Electronic Circuits ( TAB Books), and The Power Supply Handbook.