MKT1820468635 vs BFC238354333
| Part Number |
|
|
| Category | Film Capacitors | Film Capacitors |
| Manufacturer | Vishay Beyschlag/Draloric/BC Components | Vishay Beyschlag/Draloric/BC Components |
| Description | CAP FILM 0.68UF 10% 630VDC RAD | CAP FILM 0.033UF 5% 1.6KVDC RAD |
| Package | Bulk | Bulk |
| Series | MKT1820 | MMKP383 |
| Features | - | - |
| Operating Temperature | -55°C ~ 125°C | -55°C ~ 105°C |
| Mounting Type | Through Hole | Through Hole |
| Package / Case | Radial | Radial |
| Applications | DC Link, DC Filtering | High Pulse, DV/DT |
| Tolerance | ±10% | ±5% |
| Size / Dimension | 1.240" L x 0.531" W (31.50mm x 13.50mm) | 1.024" L x 0.394" W (26.00mm x 10.00mm) |
| Termination | PC Pins | PC Pins |
| Voltage Rating - AC | 220V | 550V |
| Voltage Rating - DC | 630V | 1600V (1.6kV) |
| Lead Spacing | 1.083\" (27.50mm) | 0.886\" (22.50mm) |
| Ratings | - | - |
| Height - Seated (Max) | 0.925\" (23.50mm) | 0.768\" (19.50mm) |
| Capacitance | 0.68 µF | 0.033 µF |
| ESR (Equivalent Series Resistance) | - | - |
| Dielectric Material | Polyester, Metallized | Polypropylene (PP), Metallized |

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1. Is a film capacitor AC or DC?
AC, DC
Film capacitors can be used in both AC and DC circuits. According to the current type, film capacitors can be divided into DC film capacitors and AC film capacitors.
DC film capacitors
DC film capacitors are mainly used in DC circuits and have the following characteristics:
Large capacity: has a higher capacitance.
Low withstand voltage: the withstand voltage value is relatively low.
Polarity: has positive and negative poles.
Application scenarios: commonly used in motor drives, uninterruptible power supplies (UPS), solar inverters, electronic ballasts, small automotive motors, household appliances, etc.
AC film capacitors
AC film capacitors are mainly used in AC circuits and have the following characteristics:
Small capacity: relatively small capacitance.
High withstand voltage: high withstand voltage value.
Pass AC, block DC: conduct electricity in AC circuits, equivalent to open circuits in DC circuits.
Application scenarios: widely used in industrial AC power supplies, asynchronous motor starting and operation, uninterruptible power supplies (UPS) and output filters of photovoltaic inverters, etc. -
2. What are the uses of power film capacitors?
Power film capacitors are widely used in power systems, communication equipment, automotive electronics and household appliances.
Power system
In power systems, power film capacitors are mainly used in high-voltage direct current transmission (HVDC) and reactive power compensation devices. HVDC transmission has the advantages of long transmission distance, low loss and small impact on the environment. Power film capacitors can effectively improve the voltage stability of the system, reduce voltage fluctuations and improve the quality of electric energy. In addition, power film capacitors can also be used in reactive power compensation devices. By adjusting the reactive power in the power grid, the power factor of the power grid can be improved, line loss can be reduced and the utilization rate of electric energy can be improved.
Communication equipment
In communication equipment, power film capacitors are mainly used in devices such as filters, couplers and isolators. Filters are key components in communication equipment, which are used to eliminate noise and interference in signals. Power film capacitors are small in size, light in weight and have good frequency characteristics, which can effectively improve the performance of filters. Couplers and isolators are used for signal transmission and isolation. Power film capacitors can achieve high-frequency and high-isolation coupling and isolation functions to meet the high-performance requirements of communication equipment.
Automotive electronics
In the field of automotive electronics, power film capacitors are used in electronic control units (ECUs), motor controllers, and battery management systems. ECUs are the core components of automotive electronic systems and are responsible for controlling various functions of the car. Power film capacitors can improve their reliability and stability. Motor controllers are key components of electric vehicles and are responsible for controlling the speed and torque of the motor. Power film capacitors can achieve efficient and high-precision motor control functions. Battery management systems are responsible for monitoring and managing battery status. Power film capacitors can improve their accuracy and stability.
Household appliances
In the field of household appliances, power film capacitors are mainly used in home appliances such as air conditioners, refrigerators, and washing machines. These home appliances usually require high power and high-frequency applications. The high-frequency filtering and bypass characteristics of power film capacitors make them perform well in these applications. -
3. What is a paper film capacitor?
Paper film capacitors are actually a conceptual error because "paper film capacitors" are not a standard type of capacitor. Based on the information provided, you may want to ask about paper capacitors and film capacitors.
Paper capacitors
Paper capacitors are capacitors that use paper as a dielectric. It consists of thin paper as the dielectric and aluminum foil as the electrode, which is wound into a cylindrical shape and then impregnated with a shell or epoxy resin. Paper capacitors have the following characteristics:
Low cost: Paper capacitors are usually low-cost and suitable for mass production.
Large loss: Due to its material properties, paper capacitors have large losses.
Application scenarios: Mainly used for bypass, coupling, filtering, etc. in low-frequency circuits. -
4. Will the performance of film capacitors degrade?
Yes
The performance of film capacitors will degrade. The performance degradation of film capacitors is mainly due to their internal structure and material properties.
Reasons for performance degradation
Metal plating oxidation: During the capacitor manufacturing process, there is a trace amount of air between the film layers, which may be ionized under the action of the electric field to produce ozone. Ozone is a strong oxidant that oxidizes the metal plating to produce non-conductive metal oxides, resulting in a reduction in the plate area and a decrease in the capacitor capacity.
Humid air: During the winding process of film capacitors, if the workshop environment is not properly controlled, there will be a large amount of humid air. These humid air will produce air ionization reactions when the capacitor is working, generating ozone, which further causes the capacitor capacity to decay.
Poor quality materials: The film materials used are of poor quality, such as uneven evaporation and defects on the film, which will cause the capacitor capacity to decay.

