What is an Electrolytic Capacitor?
A capacitor is generally used in an electronic circuit to filter out unwanted signals. The electrolytic capacitors in the DSM ECU are used to filter the power supply. An automobile is an extremely hostile place for electronics. The output of the alternator isn’t all that pretty to begin with. Couple that with the spark plug high voltage firing, the radiator fans, the interior fan, turn signals going on and off… the +12VDC main power line gets a lot of crud on it. Which capacitor to choose? There are a lot of different types out there – some large, some small, some really accurate, some “cleaner” for low noise applications, etc. For power supply filtering, electrolytics are almost always used. Power supplies generally require a large capacitor to absorb spikes and dips. You can’t afford not to have a steady power supply line inside of a computer – the microcontroller might act erratically or reboot. Electrolytics are chosen because they provide a lot of filtering for their small size.
