Ripple Buster cappack Xl
The Capacitor!!!!
• What is a Capacitor?
a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator.
The capacitor acts as a charge reservoir. They charge as the incoming voltage increases and discharge into the load as the voltage decreases smoothing out the signal. Caps will see varying voltage and current depending on the power applied and as well as both continuous and intermittently pulsed power
• What is esc ripple?
Ripple is the difference in voltage the fets see when they turn on - turn off (load, no load).
Acceptable ripple is normally 5% to 15% of total pack voltage. Above 20% is failure rate
• The run down
Pulse width modulation is a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discreet parts. The average value of voltage and current fed to the load is controlled by turning the switch on and off at a fast rate. This PWM on and off is done to get the desired current. The turning off of the current in combination with battery wire inductance, causes voltage spikes because the voltage wants to continue its course. these voltage spikes are higher than the battery voltage. The input caps take care of these spikes by reducing wire inductance. The longer the wire the more inductance. Therefore, using thicker wire will help but extra caps are the solution by reducing/compensating the wire inductance. So, buy adding more caps in parallel does two things, first it increases the capacitance limiting the change in voltage and distributes the current from the spikes across several caps to reduce heat. Its better to use several smaller caps in parallel instead of one big cap. Smaller caps shed heat easer and their total inductance will be lower. If the inductance per cap is lower than the inductance is paralleled too.
The main spec I would look for in a cap is low impedance and low or ultra-low ese (equivalent series resistance) otherwise the cap will get too hot. To find the esr you will have to look it up on the mfg spec sheet. You want the voltage rating on the caps to be the same or higher rating then the ones the mfg installed. Higher voltage ratings is not a problem. Capacitors have polarity like a battery positive & negative. Add the caps as close to the esc as you can. The esc is like a water tap that is switched on and off at a very fast rate so it’s best to have shorter battery wires and longer motor wires, this will help with the inductance and help lower the esc ripple.
Wat tech video's
https://m.youtube.com/watch?v=bMVF0ONVRiY&feature=youtu.be
https://m.youtube.com/watch?v=rGch07j8xSk&feature=youtu.be
Overal waar een ESC (controller) de stroom tussen de accu en de motor regelt, zijn er spanningspieken. Of het nu gaat om accelereren of remmen.
De ingebouwde (fabrieks) condensatoren op een ESC hebben als taak deze pieken op te vangen.
Waar zijn de spanningspieken van afhankelijk?
Veel factoren komen hier samen, zoals motorvermogen, KV-nummer, gewicht van het voertuig, bandenmaat, overbrengingsverhouding, batterijkwaliteit, grootte en type van de in de fabriek geïnstalleerde condensatoren.
Belast je de esc extra met oa grotere motoren, langere overbrengingsverhoudingen, hogere KV-waarden, hoger voertuiggewicht, grotere banden etc., dan kan het voorkomen dat de af fabriek geïnstalleerde condensatoren de spanningspieken niet aan kunnen. Dit kan leiden tot uitval, hogere temperatuur van de controller en zelfs uitgebrand of kapot.
Een cappack is daarom een wenselijke ondersteuning van je ESC. Je temperaturen blijven iets lager, esc krijgt meer lucht, een langere levensduur en net die paar km harder voor de speedrunners.