Simple Ways To Learn The Filter Capacitors In Electronic Circuits Perhaps you have wonder why you will find so many capacitors in electronic circuit board? They're all scattered during the complete electronic board. You may see mica capacitors, ceramic capacitors, tantalum capacitors, aluminum electrolytic capacitors, paper capacitors and etc. These in the circuit have a function and you'll find widespread applications in the electrical and electronics fields. Some of the common situations in which capacitors are employed are as follow: Electric Field-Power factor correction;-Motor start and run; and -Welding (stored energy in capacitor discharged rapidly) Electronic Field - Act as filter to eliminate ripple in power supplies; - As inter stage signal 104 ceramic capacitor coupling capacitors- A capacitor won't pass DC, but an AC signal will go through; - Tuning resonant circuits, oscillator circuits; - Decoupling in power supplies and amplifiers; - Within timing circuit; and - As waveshapers and filters In today's article I'm planning to covers capacitor become filter to remove ripple from power supplies. Once the AC signal from output transformer passed through diodes it'd become an uneven DC. A filtering section can be used to smooth out this uneven DC signal. Usually, the filter includes a number of capacitors. The capacitors are then placed involving the DC line and ground. The worth of the capacitors is chosen carefully to provide the filter circuit a certain timing constant or TC. This TC measures how quickly the circuit responds to changes in the voltage level. If the circuit has just the right timing constant, it could act to smooth the output voltage, and once the voltage leaves the filter stage, most of the variations or "ripple" must certanly be removed. The AC has been became a smooth DC. If the filter capacitors fail either increase in ESR reading or lose a number of its capacitance, the AC signal will be allowed to stay with the DC, making a signal which can be noisier than it should it. This unwanted noise signal can create problems in electronic circuit. When it happen in computer monitor power supply, the bad capacitors may cause capacity to blink, low power, voltage shutdown, no display, intermittent display problem ands many more. Now you understand just why everytime when a monitor has the complaint like above, I would first check all of the secondary side filter capacitor with my ESR meter. If all capacitors checked okay I'd then proceed to some other circuit. That's one among my troubleshooting methods. Next, perhaps you have seen all the little blue caps around a routine board? Those small value caps (usually 0.1uf 50 v or 104) will also be used to get rid of noise from electronic circuit. Then how about the event of big filter capacitors we've just mentioned above-aren't they already removed the unwanted signal? Why not one filter capacitor is enough for every single DC line voltage? The clear answer is that the big filter capacitors (large value) at the secondary side of power supplies is always
to smooth the DC and remove unwanted lower frequency noise. Meanwhile the little blue resin coated ceramic disc capacitor is more efficient in shorting quite high frequency noise spikes to ground and to preventing it from getting back into the energy supply line and traveling to other circuits.