BFC238304334 vs BFC237955114
| Part Number |
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| Category | Film Capacitors | Film Capacitors |
| Manufacturer | Vishay Beyschlag/Draloric/BC Components | Vishay Beyschlag/Draloric/BC Components |
| Description | CAP FILM 0.33UF 5% 250VDC RADIAL | CAP FILM 0.11UF 5% 400VDC RADIAL |
| Package | Bulk | Tape & Reel (TR) |
| Series | MMKP383 | MKP379 |
| Features | - | Long Life |
| Operating Temperature | -55°C ~ 105°C | -55°C ~ 85°C |
| Mounting Type | Through Hole | Through Hole |
| Package / Case | Radial | Radial |
| Applications | High Pulse, DV/DT | High Pulse, DV/DT |
| Tolerance | ±5% | ±5% |
| Size / Dimension | 0.689" L x 0.394" W (17.50mm x 10.00mm) | 0.689" L x 0.197" W (17.50mm x 5.00mm) |
| Termination | PC Pins | PC Pins |
| Voltage Rating - AC | 125V | 200V |
| Voltage Rating - DC | 250V | 400V |
| Lead Spacing | 0.591\" (15.00mm) | 0.591\" (15.00mm) |
| Ratings | - | - |
| Height - Seated (Max) | 0.650\" (16.50mm) | 0.433\" (11.00mm) |
| Capacitance | 0.33 µF | 0.11 µF |
| ESR (Equivalent Series Resistance) | - | - |
| Dielectric Material | Polypropylene (PP), 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 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. -
3. How do film capacitors fail?
High working environment temperature, improper selection of working current, exceeding the specified working voltage, harmonic current
The main reasons for film capacitor failure include the following:
High working environment temperature: Film capacitors can work normally in a temperature environment of -40℃~+105℃, but exceeding this range will accelerate thermal aging, resulting in a shortened service life, and even bursting in severe cases.
Improper selection of working current: The current value in the circuit should be less than the current value allowed by the film capacitor, otherwise it will cause the capacitor to heat up, and long-term use will shorten the life, and even burst in severe cases.
Exceeding the specified working voltage: Excessive voltage will cause partial discharge, which will then break down the capacitor and cannot be used.
There are harmonic currents: high-order harmonic currents are superimposed on fundamental currents, resulting in an increase in total current, causing capacitor load overload, internal expansion, and explosion.
Buying inferior capacitors: In order to reduce costs, some manufacturers on the market use low-quality materials to produce capacitors, which greatly reduces the actual withstand voltage and life of such capacitors.
The structural characteristics of film capacitors and the impact of the use environment on their performance:
Film capacitors are usually composed of polypropylene film, aluminum foil and plastic shell. Polypropylene film is sensitive to high temperature, which accelerates its aging and shortens the life of the capacitor. In addition, a humid environment will also cause water vapor to enter the capacitor, affecting its performance.
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4. What are the alternatives to film capacitors?
CL21 capacitors, MPB capacitors, CBB13, CBB81, MMKP82 capacitors
Alternatives to film capacitors mainly include CL21 capacitors, MPB capacitors, CBB13, CBB81 and MMKP82 capacitors. These alternatives have their own advantages and disadvantages in performance and applicable scenarios, and the specific choice depends on specific needs.
CL21 capacitors
CL21 capacitors and CBB22 capacitors can replace each other in applications such as filtering. CL21 capacitors are more stable than CBB22 capacitors under high-frequency conditions, so CL21 capacitors are more preferred in high-frequency circuits. However, CL21 capacitors are more expensive and perform better in high-frequency circuits.
MPB capacitors
MPB capacitors are boxed metallized polypropylene film capacitors with the same core as CBB22 capacitors, but with a plastic shell, which has better resistance to high temperature, moisture and sealing performance. MPB capacitors can replace CBB22 capacitors in high frequency, DC, AC and pulse high current applications, but their prices are relatively high.
CBB13, CBB81 and MMKP82 capacitors
These capacitors have a higher voltage resistance, up to 3000V, and are suitable for applications requiring higher voltages. However, they are also relatively expensive and larger in size.
