Normally, Electronic circuit requires the power supply in one direction only. The circuit will immediately damage, if the power supply to the electronic circuit is reverse against the design direction.
Hello,
I think you could use some protection diodes to avoid incorrect polarity.
You can use diodes, MOSFETs , relays etc. it depends on your application. Please go through the attached links.
https://www.edn.com/design/analog/4368527/Simple-reverse-polarity-protection-circuit-has-no-voltage-drop
http://www.electronicdesign.com/power/reverse-polarity-protection-automotive-design
The usual approach is a diode or a MOSFET in series with the circuit.
A more unconventional approach (applicable only if the power source is current-limited) is an "antiparallel" diode between + and minus that shorts the supply if the circuit in connected in reverse.
If some current path would exist "traversing" the board, additional precautions may become necessary.
With Reverse Polarity you put Voltage in reverse value at risk for the components in circuit.
To remove this voltage you have to make it zero and in proper direction it should be of desired value.
The best way is to use diode which conduct in reverse voltage so that the drop will be 0.7V.
You can add fuse at the entry point to avoid short circuit to source.
Depending on your application, and the ability to accept a voltage drop of an additional diode/s, there is another solution.
Place a series fuse in the incoming supply source, with a reversed diode to ground behind it (a very fast avalanche type). When the supply is reversed, the diode avalanches and blows the fuse, protecting the circuits behind it. Not an elegant solution, but a sure-fire way to protect the circuit from further mistakes. The fuse must carry the full load plus around 20% more - see other papers for this value. The avalanche diode must carry at least that much current, long enough to blow the fuse and probably survive for further abuse, once the fuse is replaced. Self-resetting fuse? Maybe, but be careful with the specs.
This circuit very similar to bridge rectifier but with transistors to reduce the diode drops
Diode Simply using a diode as shown in the first circuit is often a good approach. The advantages are simplicity and cost. The disadvantages are larger power loss for larger circuit loads and a substantial voltage drop. Normal rectifier diodes typically drop around 0.8 volts. If your circuit draws little power and can handle such a drop, then the blocking diode will work for you.
You can improve this circuit somewhat by using a Schottky diode. It has a lower voltage drop - usually about 0.6 volts, but you can get some lower than that. There is one potential problem with using Schottky's though. They have more reverse current leakage, so they may not offer sufficient protection. I suggest avoiding using Schottky diodes for reverse protection.
PNP Transistor A greatly improved protection circuit can be provided by using a pnp transistor as a high-side switch as shown in the second circuit. The saturated voltage is much lower than it is with diodes, so the voltage drop and power loss are much lower.
The limitations of this approach is the fact that there is some power loss from the base current, and that loss is constant regardless of the circuit's current power draw. In circuits where a very low quiescent current is typical, this approach could greatly increase it. For circuits which are usually active and draw modest amounts of power, this simple type of protection is hard to beat.
P-Channel FET For the ultimate in low voltage drop and high current capability, replacing the PNP transistor with a P-channel FET as shown in the third circuit can't be beat. Please note that the FET is actually installed in the reverse orientation as it would normally be used. This direction is so that the slight leakage current through the FET's intrinsic body diode will bias the FET on when the polarity is correct and block current when reversed, thus shutting off the FET.
If the supply voltage is less than the FETs maximum gate to source voltage, you only need the FET, without the diode or resistor. Just connect the gate directly to ground. If after checking your FET's spec sheet, you find that Vcc could exceed the maximum Vgs, then you must drop the voltage between the gate and the source. The circuit shown does exactly that. By inserting a zener diode with a voltage less than the maximum Vgs, it limits the voltage to a safe level. Calculate the resistor value to provide enough current to properly bias the zener diode chosen.