i have a +12v and -12v sources and iwant to make a circuit that switches between them without using a relay using only 1 pin on esp 32 (3.3v)

 

If you simply want to switch polarity to a load all you need is a H Bridge module. Just about any H Bridge module is easily controlled by an ESP32, ESP8266 or just about any micro-controller. Depending on load current which you don't mention there is no shortage of off the shelf modules. The more information you can provide the better the help you will receive. If a H Bridge will work for you I would avoid older modules like the L298 versions to avoid loss of your 12 VDC supply to your load. Newer modules employ MOSFETS and not the loss of the older L298 modules.

Ron

 

Does thi

i have a +12v and -12v sources and iwant to make a circuit that switches between them without using a relay using only 1 pin on esp 32 (3.3v)

Do these + and - 12 volt sources share a common ground with the ESP?

 

H Bridge module

A H bridge will reverse a motor with only a +12V supply. There are " L298N " modules that will drive two motors.

 

What Sghioto asks is of paramount importance. If the answer is no, then your only simple option is a DPDT relay.

 

Does thi

Do these + and - 12 volt sources share a common ground with the ESP?

Yes

 

OK so rather than just switching polarity to a load you want to switch two supplies? I wasn't sure.

A H bridge will reverse a motor with only a +12V supply. There are " L298N " modules that will drive two motors.

Yes, I was aware of that but since the thread starter really did not explain his project in any detail I just suggested using an H Bridge if it would fit his needs. Still no clue as to the current or if the switching will take place under load or no load. I also discourage using a L298 H Bridge module with newer better H Bridge solutions available.

Ron

 

With ±12V supplies, a half bridge will do. Two MOSFETs, and a level translator for each.

 

Discrete transistor version:

 

Discrete transistor version:

Likely need a protection circuit to keep Q4's Vgs below 24V when it's ON.

 

Likely need a protection circuit to keep Q4's Vgs below 24V when it's ON.

Good call.
Revised schematic in post #9.

 

Sounds fishy to me.
Much more information is needed.
What is the character of the 2- 12-Volt Supplies ?
What is the Load, and how much Current will be required ?
Is this project for Motor-Reversing ?, or something else ?
.
.
.

 

Discrete transistor version:
View attachment 336577

The OP is ambiguous. This circuit does what one reading says. I, however, read it to mean +12V or -12V switched to a single output.

 

With two optocouplers:


You can swap 10k-s and opto-transistors to avoid shot-through since closing fet will be faster than opening (gate will be charged slowly through 10k then). But ESP need to start first before +-12V is presented to glow one of led, otherwise both fet will be opened at begining.

 

But ESP need to start first before +-12V is presented to glow one of led, otherwise both fet will be opened at begining.

I modified your circuit that I think will eliminate that issue.

 

i have a +12v and -12v sources and iwant to make a circuit that switches between them without using a relay using only 1 pin on esp 32 (3.3v)

Without a more complete description of what you want to achieve, there is no reason for any to consider the request.
IF the TS is an "Electrical Engineer", as posted in "information", the TS should at least know what additional information we will need to be able to provide a useful answer..