Capacitors Blog

A trimmer is a miniature adjustable electrical component. It is meant to be set correctly when installed in some device, and never seen or adjusted by the device's user. Trimmers can be variable resistors (potentiometers) or variable capacitors. They are common in precision circuitry like A/V components, and may need to be adjusted when the equipment is serviced. Unlike other variable controls, trimmers are mounted directly on circuit boards, turned with a small screwdriver and rated for many fewer adjustments over their lifetime. In 1952, Marlan Bourns patented the world's first trimming potentiometer, trademarked "Trimpot".

We have below special offer for Suntan TS18H High Voltage Chip Ceramic Capacitor no. The price validity is 2 weeks from April 25 , 2008.

• High Voltage MLCC 1206 0.027uF 500V X7R 10% US$28.0/kpcs
• High Voltage MLCC 1206 0.018uF 500V X7R 10% US$25.0/kpcs
• High Voltage MLCC 1210 0.12uF 300V X7R 10% US$52.0/kpcs

3Kpcs/ Reel, ROHS
MOQ: 51 kpcs per item
Pls. send inquiries soon if you need order these items.

Suntan Technology Company Limited
---All Kinds of Capacitors

Suntan lead the unique and latest technology in manufacturing ceramic trimmer. We specialized in producing ceramic trimmer capacitors with 3mm-SMD Ceramic Trimmer Capacitor, 3mm-Special SMD Ceramic Trimmer Capacitor, 5mm Trimmer Ceramic Capacitor, 6mm and 7mm Ceramic Trimmer Capacitor etc. Following is the applications of a Ceramic Trimmer Capavcitor

Consumer Electronic Equipment
Audio & Visual Equipment -- Home VTR/VCR, VTR Camera, Television set, Video-disk Player, Digital Equipment, Radio Cassette Recorder, Hi-Fi Audio Equipment, Car Audio Equipment, Broadcast Equipment, CATV.

Industrial Electronic Equipment
Tele-communication Equipment -- Facsimile, Key Phone, Electronic telephone, electronic exchanger.
Radio Communication Equipment -- Automobile Telephone, Pocket Pager, Personal Radio.
CPU & Peripherals -- FDD, Computer, Printer, CRT Display.
Office equipment -- Word Processor.
Testing & Measuring Instruments -- Electronic Measuring Instruments, Industrial Measuring Equipment, Medical Electronics Equipment.
Factory Automation Equipment -- Numerical Control Machine, Industrial Robotics, Automatic Equipment, Ultrasonic Equipment, Components for High-frequency Circuit.

Home Appliances / Home Security Devices
Others -- Toys and Electronics Games.

The capacitor at approximately 75% of the guaranteed maximum capacitance, shall be given a treatment consisting of 5 temperature cycles as follows: Cool the capacitors to -55°C±3°C. Remove the capacitor from the cooling chamber and allow to reach room temp.

Then place in an oven at a temperature equal to maximum operating temperature ±3°C of the respective style.  Remove from oven and allow capacitor to cool to room temperature. The capacitor shall be held at the specified minimum and maximum temperatures long enough to reach equilibrium and in no case less than 15 minutes. The rate of change of temperature in cooling from room temperature, or heating above it shall not be less than 3°C per minute.

The temperature cycles shall be followed by exposures for 96 hours to a relative humidity of 95% at 40°C ±3°C. The capacitor shall then be removed from the humidity chamber and held at 25°C ±5°C with a maximum humidity of 50% for four hours.  The I.R. shall be at least 1 gigaohm, the “Q” at 1 MHz is at least 40% of initial test limit and the capacitance shall not have changed by more than±3% or ±0.5pF, whichever is greater, from its value prior to the start of the temperature cycling.

The capacitor, at approximately 75% of the guaranteed maximum capacitance, shall be tested for 250 hours at twice rated voltage, and at a temperature equal to the maximum operating temperature± 3°C for the respective style. At the end of this period the capacitance shall not have changed more than ±5% or ±0.5pF, whichever is greater, from its value before the life test. The I.R. shall be 1 gigaohm minimum and the“Q” at 1 MHz shall be a minimum of 40% of the initial test limit.

The T.C. of capacitance shall be within the limits shown in the table to the right. The T.C. shall be determined by measuring the capacitance (capacitor shall be set at approximately 75% of the guaranteed maximum capacitance) at +25, -55°C and either +85°C or +125°C,whichever is applicable to the respective style, at a frequency of 0.1 to 1 Megahertz. Each measurement shall be made after the capacitor has reached thermal stability.

Trimmer capacitors (trimmers) are miniature variable capacitors. They are designed to be mounted directly onto the circuit board and adjusted only when the circuit is built.

A small screwdriver or similar tool is required to adjust trimmers. The process of adjusting them requires patience because the presence of your hand and the tool will slightly change the capacitance of the circuit in the region of the trimmer!

Trimmer capacitors are only available with very small capacitances, normally less than 100pF. It is impossible to reduce their capacitance to zero, so they are usually specified by their minimum and maximum values, for example 2-10pF.

Suntan Technology Company Limited
----All Kinds of Capacitors

Variable capacitors are mostly used in radio tuning circuits and they are sometimes called 'tuning capacitors'. They have very small capacitance values, typically between 100pF and 500pF (100pF = 0.0001µF). The type illustrated usually has trimmers built in as well as the main variable capacitor.

Many variable capacitors have very short spindles which are not suitable for the standard knobs used for variable resistors and rotary switches. It would be wise to check that a suitable knob is available before ordering a variable capacitor.

Variable capacitors are not normally used in timing circuits because their capacitance is too small to be practical and the range of values available is very limited. Instead timing circuits use a fixed capacitor and a variable resistor if it is necessary to vary the time period.

Do you need Ceramic Trimmer Capacitor now? Suntan is a Trimmer capacitor in both SMD & radial type. We offer trimmer in:

3mm trimmer capacitor       
5mm trimmer capacitor      
6mm trimmer capacitor
7mm trimmer capacitor

Please visit our website: www.suntan.com.hk and send us email to info@capacitors.com.hk if you have any inquire.

If using an iron for manual soldering (for prototyping or repairs, for example) use an appropriate size and temperature so that the high temperature exposure of the trimmer is less than 3 seconds.
We strongly recommend the use of water soluble fluxes for soldering, followed by cleaning in water containing detergents, and then a clear water rinse.

Some operations still use Freon or similar fluorinated or chlorinated hydrocarbon solvents. These solvents have a tendency to remove the lubricant, which in turn makes for bumpy adjustment, and will degrade the tuning torque, adjustment life, and other mechanical specifications.

In general, the minimum exposure to cleaning solutions is recommended. The gentlest would be the detergent and water rinses at fairly low temperatures. When chlorinated or fluorinated hydrocarbons are used, the boards should never be plunged into the solvent solution, but rather maintained in the vapor area of the defluxing equipment, and for the minimum possible time. Most desirable would be to clean only the bottom of the printed circuit board, as with board scrubbers.

The unsealed GKG models are usually specified for consumer applications where cleaning after soldering is normally not required. Should cleaning be required, the method to use would be to clean the bottom of the board, as with board scrubbers. If a solvent is used when cleaning the GKG series, sealed versions should be specified to prevent the solvent from being trapped in the housing and degrading performance.

Other precautions for using ceramic trimmer capacitors include:

Beware of excessive handling with bare hands as, "finger oil" and dirt can bring down Q and insulation resistance values.

Terminals should not be cut or reformed, as this could cause deformation of the spring or breaking of the rotor.