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Electronic PartsSatCure sells electronic kits and components to hobbyists. The range is steadily increasing. However, before you buy anything, we urge you to read the books, below. Low ESR Capacitors High reliability Low ESR capacitors for DVD, Television, computer, Audiophile use. We stock high reliability Low ESR capacitors and, therefore, not as cheap as you might find elsewhere. We do not attempt to "price match" because we want to supply the best we can find. Please read notes, below, before ordering. In the drop-down list, the figure in brackets like (0.03) is the ESR measured in Ohms at 100kHz. Capacitors with an ESR value are the most reliable and should be used in critical applications in favour of similar capacitors without an ESR value listed. NO minimum order! If you daren't attempt the repair, see our recommended local repairers list. Click HERE. Capacitor PlagueMillions of televisions, computers, satellite TV receivers and other electronic units have been assembled with faulty electrolytic capacitors. In some cases the capacitors are simply under-rated. In most cases they come from a factory manufacturing counterfeits. Electrolytic capacitors contain a water-based liquid (electrolyte) that contains several chemicals. If the chemical mix is wrong, hydrogen gas is evolved. The result is that, after a year or so, the internal gas pressure causes the capacitor to bulge at top or bottom. Audiophile? These are NOT so-called "Audiophile" capacitors. I advocate them for audio use for one simple reason: we have chosen them specifically for their low ESR value. In a switch-mode power supply circuit, the low Effective Series Resistance allows them to run cooler than any other type of capacitors. Running cool means no frying noises and long-term reliability. Low ESR means that fast risetime pulses are snubbed so they don't intefere with the circuits carrying the signals. Whether you'll hear any difference is down to your ears and I'm not going to make any unsubstantiated claims. For audiophile use I recommend using lead-tin solder simply because it flows well and produces a smooth, shiny joint. If you insist on using lead-free solder, I recommend the type that includes silver - not because it costs more, or has any magical audio properties, but because it flows better. When you measure the maximum available height in equipment with a metal cover, make sure that it's impossible to press the cover down into contact with the capacitor when the equipment is fully assembled. If contact is likely or unavoidable, glue our "High Temperature Card HTCARD65" to the cover to prevent direct contact. The card is heat resistant and insulating. When you measure the maximum available diameter, note that the capacitor must be kept as far as possible from any heat-generating source, such as a heat sink. It may be possible to lie the capacitor flat or bend it slightly away from a heat sink. Heat is the enemy of electrolytic capacitors. We can supply "High Temperature Card HTCARD65" (see above), to place between capacitors and heatsinks, to increase reliability. If possible, fit a capacitor with a slightly higher voltage. For example, replace a 10v capacitor with one rated at 16v. Replace a 16v with one rated at 25v. This will ensure greater reliability. You may also replace a capacitor with one of a slightly larger value. For example, it is usually fine (and sometimes desirable) to replace an 820µF capacitor with a 1000µF, or a 330µF with a 470µF. In general, a physically larger (volume) capacitor will be more reliable. Remember that the manufacturer will always minimise costs by using the lowest rating or value possible but it's usually OK to uprate this slightly to improve performance and reliability. Another important parameter of an electrolytic capacitor is the ESR or "Effective Series Resistance". Again, this is something that the equipment manufacturer will skimp on and, unless you look up the capacitor manufacturer's specification sheet, there is no way of knowing this value. There is also no simple way to determine what it ought to be. However, there's a general principle that says "the lower the better". The capacitors that we stock all have low ESR values and are usually better than you'll find elsewhere. If you want a capacitor for an application where it will never get warm, our capacitors will certainly work OK but they will be "overkill". You can get cheaper elsewhere. If you are an audiophile, looking for the best possible sound, you should find our capacitors as good as the best and considerably cheaper. Choose the physically largest capacitor that will fit in the available space. Size matters.
Cheaper/Better from Auction Sites? Unfortunately, capacitor hours rating is like LNB "noise figure". You should take it with a very generous pinch of salt. The price, too, tells a story. A price that is unrealistically low suggests that the quality of the parts will also be very low. The only parameter that matters (and is easily confirmed by measurement) is the ESR. The lower the better. You might also be impressed by a "3 year guarantee" but bear in mind that 90% of eBay businesses stop trading within 6 months. Go for a well established web site that has been trading for years - such as this one.
People are still writing to me with questions such as: "My capacitors aren't bulging so does that mean they are OK?" "One of my capacitors has a brown stain so does that mean it's faulty?" A faulty capacitor can be distinguished by a bulging top or bottom and by leaking (wet to the touch) electrolyte. Any of these signs indicates a faulty capacitor but the reverse is not true because a capacitor can be faulty with no visible signs. Without one or more visible signs, it is impossible to say whether a capacitor is faulty or not, without measuring it with an ESR meter. Note that this is NOT the same as a capacitance meter, which measures capacitance. A low reading on a capacitance meter indicates a faulty capacitor but a normal reading does NOT prove that the capacitor is good. Any dry stain could be ink or glue (and frequently is) and can not be taken as an indication either way. The only absolutely certain way to test a capacitor is by using an ESR meter. If you are in doubt - and if your model of equipment is known to use poor capacitors - then the best advice is to change them as soon as convenient. If you don't do this at a time of your choosing, you may end up doing it at a most inconvenient time. Television/Computer/DVD/Sat Audiophile Resistors Our MFR5 resistors are metal film type (high stability, low noise) and rated at 0.75 Watts (heat dissipation) and will withstand up to 350 volts. They are also physically small (3.2mm diameter x 10mm long) and accurate (+/- 1%) with a temperature coefficient (value drift) of only 100ppm per degree C change in temperature. Tinned copper wires are 0.8mm diameter and approx. 21mm long. They are so versatile that they can be used in audiophile applications, valve and transistor circuits and in high voltage power supplies. If you are in any doubt, this is the resistor to choose! Sold individually at 69p each but with automatic discounts for quantity (breaks at 10, 100, 500). Audiophile? These are NOT so-called "Audiophile" resistors. I advocate them for audio use for one simple reason: they have a low temperature coefficient, which makes them very stable. The metal film means that they generate minimal electrical noise. In addition, they are rated at 350 volts, which means that they can be used in valve circuits without any fear of breakdown or reliability problems. Whether you'll hear any difference is down to your ears and I'm not going to make any unsubstantiated claims. For audiophile use I recommend using lead-tin solder simply because it flows well and produces a smooth, shiny joint. If you insist on using lead-free solder, I recommend the type that includes silver - not because it costs more, or has any magical audio properties, but because it flows better.
Small Carbon Film Resistors We stock 1/4 Watt carbon film resistors - general purpose, low cost and rated at 0.25 Watts (heat dissipation) and will withstand up to 250 volts. They are also physically small (approx. 2.3mm diameter x 6.5mm long) and only moderately accurate (+/- 5%). Tinned copper wires are 0.7mm diameter and approx. 25mm long. They can be used in hobby applications, transistor circuits and for repairs where they will replace a similar 0.25 Watt resistor. If you are in any doubt, please ask.
Transistors Some of our stock are obsolete and almost impossible to obtain elsewhere. Some are modern. They can be used in hobby applications, transistor circuits and for repairs where they will replace a similar transistor. If you are in any doubt, please ask. Sold individually at 10p each but with automatic discounts for quantity.
Equipment Fuses (not for mains power plugs) We stock 20mm glass case Anti-surge fuses - sold in packs of 10.
The famous LITZ wire! Constructed of 24 strands of hair-thick 0.04mm diameter enamelled copper wire with a binding of Japanese silk. Each strand is individually insulated with the enamel coating. This wire is designed specifically for its extremely high frequency capability and is used primarily for winding inductors in radio equipment. However, its extremely low weight, flexibility and excellent frequency characteristics also make it ideal for use in transcription unit tone (pickup) arms and similar audiophile applications.
Loudspeaker Cable Pro79 loudspeaker cable designated "oxygen-free-copper" and having 79 x 0.12mm strands encased in colourless plastic insulation.
LS13/100WB economy Flex Can be used as speaker cable or twin flex for low voltage applications (burglar alarm, doorbell etc.) White pair with thin black stripe on one. PVC insulated.
The first is a downloadable eBook, which is free and you can get it right now. The second is a printed book sold by Amazon (and other book sellers). FREE - Beginners Guide to Electronics Easier to understand than anything you've read previously! Martin has a knack of explaining technical subjects in simple language. Components covered include resistors, diodes, transistors and capacitors. As an example, it describes in detail how to build a flashing LED circuit on perforated stripboard ("Veroboard") with a photograph of every stage. This is NOT just another boring technical eBook full of mathematical equations. You'll like it! Ideal for everyone from the young student to the retired lady looking for a new hobby. You'll definitely want more! Download it FREE now! (about 470k file size) Make: Electronics. Learning Through Discovery (Paperback) Want to learn the fundamentals of electronics in a fun, hands-on way? With Make: Electronics, you'll start working on real projects as soon as you crack open the book. Explore all of the key components and essential principles through a series of fascinating experiments. You'll build the circuits first, then learn the theory behind them! Build working devices, from simple to complex You'll start with the basics and then move on to more complicated projects. Go from switching circuits to integrated circuits, and from simple alarms to programmable microcontrollers. Step-by-step instructions and more than 500 full-color photographs and illustrations will help you use -- and understand -- electronics concepts and techniques. Read more information | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
