Can we convert -12 to +12 ?

[Besto]

I have a power supply (THM 60-4822WI from Traco Power). Its output is -12 and +12 with one common. I need +24 volts with proper ground . How can I achieve that?

 

[cupoftea]

Is it isolated?
Just use the -12 as 0v, and the +12 as 24V.... have a diode across each "half". Add an overall +35V rated cap across your "new" +24v.

 

[KlausST]

Its output is -12 and +12 with one common. I need +24 volts with proper ground . How can I achieve that?

just connect load to -12V and +12V. That´s it.

Klaus

 

[barry]

just connect load to -12V and +12V. That´s it.

Klaus

As long as common is floating and not connected to earth ground.

 

[Easy peasy]

Looking at the data sheet you have 24V from pin 4 to 8:

Did you think to read the data sheet ?

 

[Besto]

Looking at the data sheet you have 24V from pin 4 to 8:
View attachment 194626

Did you think to read the data sheet ?

I got it. I wanted to know if I can use -Vout as ground and +Vout as 24 volts.
Will there be any problems?

As long as common is floating and not connected to earth ground.

this is helpfull

just connect load to -12V and +12V. That´s it.

Klaus

I need to know about the ground.

 

[KlausST]

I need to know about the ground.

"Ground" is what an electronics designer "defines" as ground. Usually it´s where voltages are reference to.

Say you have two 1.5V batteries in series.

* You may define the most negative point as GND
--> then you get +1.5V and +3.0V respectively

* you may define the mid point as GND
--> then you get -1.5V and +1.5V respectively

* you may set the most positive as GND
--> then you get -3.0V and -1.5V respectively

Does any of the batteries has a dedicated GND pin? --> no

Does your power supply has a dedicated GND output pin? --> no. Thus you are free to connect and name the nodes as you like.

Btw: a 12V car battery consits of 6 cells with 2V each in series. Initially they are six independent cells, each with independent 2V.
They are all connected in series. And the fact that the "mid points" are not accessable ... does not change anything. The voltage of the six cells combined gives a total of 12V. Indeed it´s by 4 cells more "complicated" than your power supply.

***
In opposite:
A logic IC has a dedicated GND pin. It is strongly recommended to connect it to the application´s GND. It acts as a reference for the power supply VCC as well as for the digital input and output signals.

Klaus

 

[mtwieg]

I got it. I wanted to know if I can use -Vout as ground and +Vout as 24 volts.
Will there be any problems?

If you do not connect the Common pin to anything, then yes it should work. You should be able to treat the dual-output models the same as the single-output models.

 

[barry]

“Ground is where you plant potatoes”.

Since the outputs are isolated from the rest of the world, you can arbitrarily call any of the 3 pins “ground”.

 

[Easy peasy]

Connect the bottom of the -12V supply to your external circuit "ground" this gives you 24V relative to your " ground "

the outputs are isolated from the input - so "ground" can be whatever you choose.

 

[Besto]

"Ground" is what an electronics designer "defines" as ground. Usually it´s where voltages are reference to.

Say you have two 1.5V batteries in series.

* You may define the most negative point as GND
--> then you get +1.5V and +3.0V respectively

* you may define the mid point as GND
--> then you get -1.5V and +1.5V respectively

* you may set the most positive as GND
--> then you get -3.0V and -1.5V respectively

Does any of the batteries has a dedicated GND pin? --> no

Does your power supply has a dedicated GND output pin? --> no. Thus you are free to connect and name the nodes as you like.

Btw: a 12V car battery consits of 6 cells with 2V each in series. Initially they are six independent cells, each with independent 2V.
They are all connected in series. And the fact that the "mid points" are not accessable ... does not change anything. The voltage of the six cells combined gives a total of 12V. Indeed it´s by 4 cells more "complicated" than your power supply.

***
In opposite:
A logic IC has a dedicated GND pin. It is strongly recommended to connect it to the application´s GND. It acts as a reference for the power supply VCC as well as for the digital input and output signals.

Klaus

Thank you. I understand the concept.

I also want to know if any circuit can convert -12 volts to +12 volts.

 

[KlausST]

Hi,

ANY isolated 12V --> 12V DCDC converter will do.
But I don´t see how "another +12V" can help.

--> provide a sketch of your idea

Klaus

 

[Easy peasy]

A buck-boost power circuit can convert -12 to +12.

 

[Besto]

Hi,

ANY isolated 12V --> 12V DCDC converter will do.
But I don´t see how "another +12V" can help.

--> provide a sketch of your idea

Klaus

I want a circuit like this.

 

[KlausST]

Hi,

schematic wise your "circuit" needs to be connected with COMMON.

Function wise: you don´t get 24V with it ... but you asked for a 24V solution in post#1

Klaus

 

[Besto]

Hi,

schematic wise your "circuit" needs to be connected with COMMON.

Function wise: you don´t get 24V with it ... but you asked for a 24V solution in post#1

Klaus

Yes. I was thinking if I could get a 24 v output from that I could take 2 12-volt outputs with another converter. If I take one 12-volt output, voltage is not stable when I connect the load.

 

[BradtheRad]

Simple charge-pump converts -12V to positive 11V, light load. Supply and load both share the same ground.

Some rearranging allows a similar circuit to double +12V to +23 or 24V.
To build in real-life the SPDT switch can be a half-bridge as you choose.

By adding diode-capacitor stages you can obtain greater volt amplitudes.

Link below runs this schematic at website of Falstad's animated interactive simulator:

tinyurl.com/22amxgnb

 

[Besto]

Simple charge-pump converts -12V to positive 11V, light load. Supply and load both share the same ground.

Some rearranging allows a similar circuit to double +12V to +23 or 24V.
To build in real-life the SPDT switch can be a half-bridge as you choose.

By adding diode-capacitor stages you can obtain greater volt amplitudes.
View attachment 194639

Link below runs this schematic at website of Falstad's animated interactive simulator:

tinyurl.com/22amxgnb

Thankyou

 

[KlausST]

Simple charge-pump converts -12V to positive 11V, light load.

Yes, as you said light load.
Lets say a couple of 10mA.

But I guess the OP is not aware that having two times +12V referenced to GND .... can not give 24V!!

Klaus