Another power supply question, bi-polar

[MikeMl]

... But basically is the idea of making this a bi-polar supply just not going to work?

The only way you can make a bipolar supply out of a 3650 is to own TWO of them and connect them in series. Call the middle connection 0V. Then you will have two voltages V+ and V- which can be independently adjusted with TWO knobs

 

[Cobalt60]

OK well just for a better understanding, is it likely (or possible) that my 3650 is what is known as a "split" supply? That is to say, internally, it would have 2 voltage regulators, one rated for +18V, the other -18V, to achieve 36V?

I have seen a couple schematics for DIY variable bench supplies designed in this way, which I do not believe are claimed to be bi-polar supplies.

 

[Ayaskanta]

It might be... I'm still confused whether its split as -18V to +18V or -36V to +36V Well you must definitely turn the knob to the maximum extent and check using a Multimeter

 

[forumlicker007]

A 0-36 V supply can be a -18 0 +18 V supply too.

 

[tcmtech]

Could be a split source. It just has one lead broken off on the inside maybe.
I have worked on many power supplies and most of them have a bypass capacitor and a high ohm resistor going from one or both ouput lines back to a common ground point. usualy attached to the ground line of the power cord. The actual power outputs are floating themselves.
But some cheap designs or forign designs do use diffrent layouts.

 

[MikeMl]

OK well just for a better understanding, is it likely (or possible) that my 3650 is what is known as a "split" supply? That is to say, internally, it would have 2 voltage regulators, one rated for +18V, the other -18V, to achieve 36V?...

For the third time; NO!!!! I Googled it and found the specs on line. You can do it too.

 

[Cobalt60]

You found the specs for it, or a schematic? I know that the specs are 0 to +36V, what I am curious to know is the internal design of the supply. I have found VERY little info on this supply through Google, so if you could share whatever link you have I would appreciate it.

Some power supplies use a variable positive and negative regulator, which vary their voltage at the same rate as each other (pots ganged to each other), but the overall output is entirely positive. So, right now I am trying to establish a distinction between a "bi-polar" power supply and a "split" power supply.

 

[Cobalt60]

And BTW, there is FAR more info printed on the back of this power supply than I have found through Google. I could simply type whats on the back of the power supply into this very post and then this post would be the number one place to go if you want to find info on the Power Designs 3650.

 

[Cobalt60]

using the following link, I am currently at the section "Rectifier Types" and "Full Wave rectifiers". I think this is more or less where my understanding of power supply design is incomplete, and is probably why I am stuck on the exact definitions of "bi-polar", "split", and "dual" supplies.

 

[electech2u]

A 0-36 variable suppy mans you get a max. supply of +36V.
Your bench power supply probably has three knobs. Red, Black and Green(?)
Red for positive voltage, green for negative and black for ground. In this case the voltage varies from the negative maximum voltage to 0 to positive maximum voltage.

i would guess its red for + black for - an green for ground. a bipolar power supply is like two supplies with ground at zero volts and one supply is a positive voltage while the other is a negative voltage ( electrons are moving in the opposite direction) op amps often use a bipolar supply and so do some audio amplifier stages where two transistors share the making of their output waveform (audio is alternating current or ac with a frquency under 20KHz or so). To learn about power supplies first learn how transformers and diodes work, then how capacitors and resistors work, then transistors and zener diodes,and then you about have it figured out.

 

[Sceadwian]

I don't know why people keep posting, the question was answered back there with MikeMi and my posts. A floating 0-36 volt supply can be + or - 36 volts depending on which rail you decide to ground. It can't be BOTH at the same time. You can create 'virtual grounds' but these are at best references for op amps and not considered dual supplies. You can use two floating supplies and ground the center tap for dual supplies as I mentioned previously.

 

[electech2u]

I don't know why people keep posting, the question was answered back there with MikeMi and my posts.

I didnt realize all the questions were here just for you, i will leave the group and let you answer them all so as not to upset your world.

 

[Sceadwian]

Don't be grumpy electech. But by all means leave, no one will notice, like no one would notice if I did =) Either way I'm not particularly upset.

 

[tcmtech]

Full moon coming!
Everybody gets a little pissy around then. Just read a few threads that are a week or two old! The background tension on the forum has gradualy been rising all week!