How do i pit a botage limit where it cutoofs if it exceeds it to protect connected devices

 

Pit a botage limit?

 

A voltage limit where it cuts off if the voltage exceeds that of a connected devices' maximum voltage?
That is usually part of a voltage regulator circuit. Is there any particular circuit you are considering?


The circuit above automatically shorts out the power supply and blows the fuse if the maximum safe voltage is exceeded.This kind of circuit is referred to as a crowbar circuit. There are other techniques as well.

 

A voltage limit where it cuts off if the voltage exceeds that of a connected devices' maximum voltage?
That is usually part of a voltage regulator circuit. Is there any particular circuit you are considering?

View attachment 287033
The circuit above automatically shorts out the power supply and blows the fuse if the maximum safe voltage is exceeded.This kind of circuit is referred to as a crowbar circuit. There are other techniques as well.

Thank a lot for this circuit

 

The scheme used to protect against an over-voltage condition depends a whole lot on what sort of system is involved. The arrangement for disconnecting an over voltage in a mains power system is quite different from the one protecting against alternator regulator failing in a car, and both are quite different from the one protecting equipment connected to an antenna from excess voltage.
So without more details there will be no answer!!

 

The scheme used to protect against an over-voltage condition depends a whole lot on what sort of system is involved. The arrangement for disconnecting an over voltage in a mains power system is quite different from the one protecting against alternator regulator failing in a car, and both are quite different from the one protecting equipment connected to an antenna from excess voltage.
So without more details there will be no answer!!

Im protecting a class d amp so i wanted a full cutoff of power when the voltage increases anything over 24v

 

Are you protecting the power input to the amplifier from an over voltage situation on the power supply, or protecting the speakers from an overvoltage situation on the amplifier output?

 

Are you protecting the power input to the amplifier from an over voltage situation on the power supply, or protecting the speakers from an overvoltage situation on the amplifier output?

The power input

 

I suggest a shunt zener diode and a series fuse. The zener diode must be able to carry enough current to pop the fuse. This is the brute force method, suitable if the over voltage will be more than momentary spikes. To also protect against spikes, a series inductance followed by a large shunt capacitor will often be adequate.
Certainly the crowbar scheme is effective.
I have also seen some military equipment with a power protection module rated to protect against polarity reversal, AC not DC, and over voltage.
Can we see the circuit of the power supply, or is this to be in the mains input portion?

 

What kind of power supply are you using where you are worried about over-voltage?

 

What kind of power supply are you using where you are worried about over-voltage?

I got this tru rated pc psu but im ussing a boost conveter to boost the voltage tp 24v so i was worried the boost comverter might fail and send more than 24v

 

I got this tru rated pc psu but im ussing a boost conveter to boost the voltage tp 24v so i was worried the boost comverter might fail and send more than 24v

We have no hint as to what the "tru rated pc psu " is or what voltage it supplies or it's current capability. Then there is some sort of boost converter to raise an unknown voltage up to 24 volts.

The circuit shown in post #3 will provide the requested protection, most likely. GOOD LUCK.

 

We have no hint as to what the "tru rated pc psu " is or what voltage it supplies or it's current capability. Then there is some sort of boost converter to raise an unknown voltage up to 24 volts.

The circuit shown in post #3 will provide the requested protection, most likely. GOOD LUCK.

Oh sorry its a Corsair cx 750 bronze im using the 12 v on it

 

Oh sorry its a Corsair cx 750 bronze im using the 12 v on it

Does it have a -12V?

 

Does it have a -12V?

Yes but i dint know the use

 

Yes but i dint know the use

You could get 24V from the +12V and -12V outputs. However, the -12V might have a limited amount of current available.

 

What I think is being done is that a DC power supply ( Corsair cx 750 bronze ) is being used to supply 12 volts to a circuit that boosts it to 24 volts, to feed a "class D" amplifier that is intended to operate from 24 volts.
The TS "does not know how to use" the negative 12 volt output from the power supply.

A great deal of thought has been wasted, it appears, because the TS did not provide enough information with the initial question.
"How to use the negative 12 volts and the positive 12 volts to power an amplifier that requires 24 volts power" would have lead to a suitable answer directly.

 

What I think is being done is that a DC power supply ( Corsair cx 750 bronze ) is being used to supply 12 volts to a circuit that boosts it to 24 volts, to feed a "class D" amplifier that is intended to operate from 24 volts.
The TS "does not know how to use" the negative 12 volt output from the power supply.

A great deal of thought has been wasted, it appears, because the TS did not provide enough information with the initial question.
"How to use the negative 12 volts and the positive 12 volts to power an amplifier that requires 24 volts power" would have lead to a suitable answer directly.

Really sorry for not providing adequate information about my concern

 

You could get 24V from the +12V and -12V outputs. However, the -12V might have a limited amount of current available.

my-12v rating is only 0.3A while tge +12 can go upto 50A and i need a 24v 5A to power my amp, so I don't think this would work?

 

my-12v rating is only 0.3A while tge +12 can go upto 50A and i need a 24v 5A to power my amp, so I don't think this would work?

True.