A power strip surge protector circuit is like a superhero for your plugs.
It protects your devices from sudden bursts of electricity called power surges or spikes.
These surges can happen during storms or even when other appliances turn on and off.
This circuit, often found built into power strips uses special parts called MOVs to soak up that extra electricity and send it safely away from your gadgets keeping them safe and sound.
So you can plug in all your devices without worrying about surprise zaps from the wall.
Circuit Working:
Parts List:
| Category | Component | Quantity | Notes |
|---|---|---|---|
| Capacitors | PPC 0.1µF 400V | 1 | |
| PPC 4712KV | 2 | ||
| MOV 431KD14 | 1 | ||
| Semiconductors | Coil (pair of 20 Turns 22 SWG) | 1 | |
| Other | Fuse | 1 |
Here is a circuit for a power strip surge protector that serves as a protective device for power supply units.
Such spike protection circuits are commonly found in multi socket switchboards used for connecting computer peripherals.
This circuit is designed to protect electronic and electrical devices from mains transients and spikes.
In the event of heavy transients in the mains the metal oxide varistor in the circuit will short circuit the lines causing the fuse to blow out.
The power supply guard circuit consists of a MOV 431KD14, a 0.1 uF X2 rated AC capacitor a toroidal transformer and two 2kV disc capacitors.
Metal Oxide Varistor MOV contains a ceramic mass of zinc oxide grains surrounded by a matrix of other metal oxides like bismuth, cobalt, manganese, etc. sandwiched between two metal plates forming the electrodes.
Each grains boundary with its neighbor forms a diode junction allowing current to flow in only one direction.
When a small or moderate voltage is applied across the electrodes only a tiny current flows due to reverse leakage through the diode junctions.
However, when a large voltage is applied the diode junction breaks down due to a combination of thermionic emission and electron tunneling allowing a large current to flow.
Varistors can absorb part of a surge, and the extent of protection depends on the equipment and the specific varistor chosen.
Formula:
From the above circuit diagram we can use the formula for calculating coil Inductor.
It is conceivable that an inductor filters out high frequency transients or suppresses noise.
The inductive reactance XL of an inductor is calculated using the following formula:
XL = 2 * π * f * L
where,
- XL : is the inductive reactance in Ohms
- π : (pi) is a mathematical constant (around 3.14).
- L: is the inductors inductance measured in henrys H and
- f: is the frequency of the incoming current Hz.
Note:
Beyond the formula for individual components, a surge protector circuits performance is dependent on a number of other parameters.
Power strip surge protectors are made to withstand particular voltage and surge current specifications.
Safety is the first priority when building a surge protector circuit, thus it is critical to consult with certified electrical experts and pertinent safety requirements.
How to Build:
To build a Simple Power Strip Surge Protector Circuit follow the below mentioned steps:
- Connect one terminal of the C1 MOV metal oxide varistor to the live wire of the input power supply.
- Connect the other terminal of the MOV to one terminal of the C2 rated AC capacitor.
- Connect the other terminal of the C2 rated AC capacitor to the live terminal of the output power supply.
- Connect the neutral wire of the input power supply directly to the neutral terminal of the output power supply.
- Connect the toroidal transformer across the live and neutral terminals of the output power supply.
- This transformer helps in providing isolation.
- Finally, connect the two 2kV disc capacitors across the output terminals for additional spike protection.
Note:
- Make sure to follow safety precautions when working with mains electricity such as disconnecting power before making any connections and ensuring that all components are rated for the voltage and current they will be subjected to.
Conclusion:
A Power Strip Surge Protector Circuit is a vital component in power strips or surge protectors designed to safeguard electronic devices from voltage spikes and surges.
Using components like Metal Oxide Varistors, these circuits divert excess voltage to the ground protecting devices from potential damage.