---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Thu 05/25/17: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:09 AM - Re: Kolb-List Digest: 5 Msgs - 05/24/17 (George Bearden) 2. 05:54 AM - Re: Fuel Pump (Denny Baber) 3. 07:49 AM - Re is 12 v 12 volts (B Young) 4. 10:25 AM - Re: Fuel Pump (Richard Girard) 5. 10:44 AM - Re: Fuel Pump (B Young) ________________________________ Message 1 _____________________________________ Time: 02:09:42 AM PST US From: "George Bearden" Subject: Kolb-List: RE: Kolb-List Digest: 5 Msgs - 05/24/17 Richard Girard said: "12 volts DC is 12 volts DC" This is not a true statement, since it is implying that "all we need is 12c DC" for stuff to work. Sometimes (and IIRC this time) it *isn't* really 12v DC, but only AVERAGES out to that. Sometimes this makes a big difference. Also sometimes you need 50 amps at 12v DC. Thus one can see that not ALL 12v DC's are created equal, since the Rotax cannot produce 50A. ________________________________ Message 2 _____________________________________ Time: 05:54:25 AM PST US From: Denny Baber Subject: Re: Kolb-List: Fuel Pump What size capacitor should I use? Respectfully, Dennis Baber Stay Curious ________________________________ Message 3 _____________________________________ Time: 07:49:54 AM PST US From: B Young Subject: Kolb-List: Re is 12 v 12 volts This is a lot of rambling. Just hit delete if your not interested Do not archive 12 v is 12 volts end of statement! That is a standard. The amount of power to push 1 amp through a 12 ohm resistor It is what we perceive to be 12 volts may or may not be 12 v. Our aircraft while running will put out anywhere from 10 to 35 volts ac. Some equipment will run on ac. Most needs DC. In order to convert ac to DC we need some type of rectifier. The most simple is a single diode. Which will provide pulsating DC. If we use 4 diodes we get a full bridge rectifier. It still provides pulsating DC but with twice the energy. By adding a capasitor the pulsating DC becomes a rippled DC. Adding a battery smooths it out even more. Depending on the frequency the addition of an inductor may also help. Tmi too much information A 12 v ac circuit will push 1 amp through a 12 ohm resistor. BUT if you look at it with a peak to peak ac meter, or an oscilloscope it will show 14 1/2 volts plus or minus but on an rms (root mean squared) meter it will show 12v. To get the average 12 volts out of 14 1/2 volts, the top of the voltage curve is clipped off and used to fill in the gaps see the red and blue in last illustration. Now if you need 50 amps on a momentary basis. You can do it with a 1/2 amp supply. Provided you have a storage unit to put it till needed. Ever heard of a battery? The size of battery is determined by the amp draw required and the duration it is needed. If amp draw and duration are high,, a larger power supply is needed. If we have too small of battery or wire and need 50 amps the voltage will crash to near 0, or we will burn something up in the process. Example,, a fuze will kill the power and prevent a fire. Did I mention that our planes generate around 35 vac well we use 12 and burn the rest up as heat. Thus the purpose of the heat sink on the regulator. Did I say we use 12??? Silly me, the voltage regulator clamps off at 13.8 to 14 v DC.. this allows us to charge a 12 v battery which when fully charged runs about 12.8 volts... So 12 volts is exactly 12 volts,,, what we preciece to be 12 volts is well close to 12 v. Boyd Young ________________________________ Message 4 _____________________________________ Time: 10:25:49 AM PST US From: Richard Girard Subject: Re: Kolb-List: Fuel Pump Dennis, Look at page 18-3 of the Two Stroke Installation manual. Rick On Thu, May 25, 2017 at 7:53 AM, Denny Baber wrote: > > What size capacitor should I use? > > > Respectfully, > Dennis Baber > > Stay Curious > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ________________________________ Message 5 _____________________________________ Time: 10:44:46 AM PST US From: B Young Subject: Re: Kolb-List: Fuel Pump 25v 22000 mf capacitor >> >> >> What size capacitor should I use? >> >> ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.