jbcapacitors blog

Here are precautions in using aluminum electrolytic capacitors at high altitudes, such as in 
mountainous regions and in aircrafts.

As the altitude rises, the air pressure decreases. Therefore, if the capacitor is used at high altitudes, the atmospheric pressure becomes lower than the internal pressure of the capacitor. Due to the 
construction of the aluminum electrolytic capacitor, there is no concern in using them at altitudes lower than about 10,000 (m).

A run capacitor is a particular type of capacitor. A run capacitor uses the charge stored in the dielectric in order to boost the electrical current providing power to an electric motor. This type of capacitor is created to maintain a charge during constant use of the motor. These capacitors are often found in devices, such as heaters, that are continuously running.

One variety of run capacitor is often used in air conditioners. This type of run capacitor is called a dual run capacitor, and uses two run capacitors for two different functions. In an air conditioner, for example, one run capacitor is used to boost the fan motor, and another is used to boost the compressor motor.

Run capacitors typically are classified at 370 or 440 volts. It is necessary to ensure that the correct rating of run capacitor is installed in an engine. If a run capacitor with an incorrect voltage rating is installed in a motor that requires a capacitor for second-phase energy, it will throw off the magnetic field. An uneven magnetic field will cause the rotor to slow in the uneven spots, which increases energy noise, as well as power consumption, and can also cause performance problems and overheating issues.

This capacitor is small, with long lifespan and good self-healing ability. It is widely used as the start-up and running capacitor, especially for micro water pumps, cleaning machines, washing machines, and single-phase water pump motors.

Features:

jb film capacitors offers a full voltage range, from 63VDC to 2000VDC; our high voltage film capacitors include JFP (epoxy coating dipped type) and JFQ (box type) two series. JFA mylar polyester film capacitors, 1000V, 1200V is very popular. Also AC voltage and DC voltage both available, AC type film capacitors include JFC (AC metallized polyester film capacitors), JFN & JFO X2 class and JFT X1 class......

Tolerance range: ±1%, ±2%, ±2.5%, ±5%, ±10%

Temperature range: normally film capacitors temperature range is -40'C to 85'C, for some series we can provide a wide temperature range up to 125'C.

jb film capacitors technology available: winding technology and stacked technology (JFJ mini box series); single side metallized structure and double sided metallized structure (JFQ series) Safety Approvals of film capacitors: UL, TUV, CE, VDE...., X2 class, X1 class

Packaging: Ammo packaging and Bulk packaging both available, and all jb film capacitors are RoHS compliant

For reflow, use thermal conduction systems such as infrared radiation (IR) or hot blast. Vapor heat 
transfer systems (VPS) are not recommended.

Observe proper soldering conditions (temperature, time, etc.).
Do not exceed the specified limits.
Temperature measuring method: Measure temperature in assuming quantitative production, by sticking the thermo-couple to the capacitor upper part with epoxy adhesives.
Consult us for additional reflow restrictions.

For reflow, use thermal conduction systems such as infrared radiation (IR) or hot blast. Vapor heat transfer systems (VPS) are not recommended.

Observe proper soldering conditions (temperature, time, etc.).

Do not exceed the specified limits.

Temperature measuring method: Measure temperature in assuming quantitative production, by sticking the thermo-couple to the capacitor upper part with epoxy adhesives.

Consult us for additional reflow restrictions.

jb Aluminum Electrolytic Capacitor - JNE

Features

• Load life of 2000 hours at 105°C
• High ripple current
• Smaller size
• PCB Mounting

Construction

• Charge/discharge-proof, polar
• Aluminum case, fully insulated with PVC
• Version with PET insulation available
• Version with additional PET insulation cap on terminal side
• available for insulating the capacitor from the PCB
• Snap-in solder pins to hold component in place on PC-board
• Minus pole marking on case surface
• Minus pole not insulated from case
• Overload protection by safety vent on the base

In theory, capacitors can be coupled both in series and parallel. If you need a 100MF cap and have two at 50MF, you can connect them in parallel, and that will give you 100MF (and same voltage rating as each). If you couple them in series, you get half the capacitance, and double voltage rating. But coupling electrolytic capacitors in series to get higher voltage rating must generally be discouraged. For this to work, you must be sure that the two (or more) caps share the voltage load properly; a resistor network can augment this, but if leakage currents are markedly different or the capacitors age differently, you are looking at a potential disaster, so do this only as a last resort, if at all.

As already mentioned, never go below the voltage rating of the original part. Standards in voltage ratings have changed over the years, so you may not be able to find an exact replacement for the 250V capacitor you want to replace. Instead use 270V or even more. The only adverse effects of using a too high rating is price and, maybe, physical size; small problems compared to the risk of a capacitor impersonating a large firecracker inside your equipment!

Same is true of capacitance values: Standards have changed, and instead of old values like 15MF, 32MF, 50MF, etc, you will find 16, 33, 67, and such. The capacitance values of electrolytic capacitors are normally not very critical to the circuitry function, especially not in filters. A good rule of thumb is to go for the range between -20% to +100% of the original value, of course choosing a value as close as you can get.

There is a caveat here: If those capacitors have already been changed once, the values you look at may already deviate from the original values. If a 260V 40MF capacitor has sometime along the route been replaced with a 450V 67MF, you could be heading for problems; a 650V 100MF replacement will probably work, but we are getting out of bounds (oversize filter caps put extra strain on rectifier tubes, not to mention the price). So it would be nice to make a rough calculation to see if the value we are aiming for is reasonable.

Aluminum electrolytic capacitors have a bi-polar structure. This is marked on the body of the capacitor. A capacitor must not be mounted with reversed polarity. The application of an AC or reverse voltage may cause a short circuit or damage the capacitor. Bi-polar capacitors must not be used in AC applications, where the polarity may be reversed in the circuits or is unknown.

jb SMD Aluminum Electrolytic Capacitor Product List

JCS - 2000H at 85°C SMD Aluminum Electrolytic Capacitor
JCK - 1000H at 105°C SMD Aluminum Electrolytic Capacitor

SMD aluminum electrolytic capacitors, jb Capacitors provides the most common series: 2000h at 85°C SMD aluminum electrolytic capacitors and 1000h at 105°C SMD aluminum electrolytic capacitors. jb Capacitors sell very competitive prices and our monthly output for SMD aluminum electrolytic capacitors can reach 30 millions units.

The typical temperature range for aluminum electrolytic capacitors is –40 °C to 85 °C or 105 °C. Capacitance varies about +5% –40% over the range with the capacitance loss all at cold temperatures. Capacitors rated –55 °C generally only have –10 % to –20 % capacitance loss at –40 °C. Cold temperature performance for rated voltages of 300 V and higher is often worse, and temperature performance varies by manufacturer.